Computing stuff tied to the physical world

Archive for the ‘News’ Category

Wrapping up

In AVR, Hardware, Musings, News, Software on Oct 6, 2013 at 00:01

I’m writing this post while one of the test JeeNode Micro’s here at JeeLabs is nearing its eighth month of operation on a single coin cell:


It’s running the radioBlip2 sketch, sending out packets with an incrementing long integer packet count, roughly once every minute:

Screen Shot 2013-10-04 at 15.44.58

The battery voltage is also tracked, using a nice little trick which lets the ATtiny measure its own supply voltage. As you can see, the battery is getting weaker, dropping in voltage after each 25 mA transmission pulse, but still recovering very nicely before the next transmission:

Screen Shot 2013-10-04 at 15.45.45

Fascinating stuff. A bit like my energy levels, I think :)

But this post is not just about reporting ultra low-power consumption. It’s also my way of announcing that I’ve decided to wrap up this daily weblog and call it quits. There will be no new posts after this one. But this weblog will remain online, and so will the forum & shop.

I know from the many emails I’ve received over the years that many of you have been enjoying this weblog – some of you even from the very beginning, almost 5 years ago. Thank you. Unfortunately, I really need to find a new way to push myself forward.

This is post # 1400, with over 6000 comments to date. Your encouragement, thank-you’s, insightful comments, corrections and additions – I’m deeply grateful for each one of them. I hope that the passion which has always driven me to explore this computing stuff tied to the physical world technology and to write about these adventures, have helped you appreciate the creativity that comes with engineering and invention, and have maybe even tempted you to take steps to explore and learn beyond the things you already knew.

In fact, I sincerely hope that these pages will continue to encourage and inspire new visitors who stumble upon this weblog in the future. For those visitors, here’s a quick summary of the recent flashback posts, to help you find your way around on this weblog:

Please don’t ever stop exploring and pushing the boundaries of imagination and creativity – be it your own or that of others. There is infinite potential in each of us, and I’m certain that if we can tap even just a tiny fraction of it, the world will be a better place.

I’d like to think that I’ve played my part in this and wish you a lot of happy tinkering.

Take care,
Jean-Claude Wippler

PS. For a glimpse of of what I’m considering doing next, see this page. I can assure you that my interests and passions have not changed, and that I’ll remain as active as ever w.r.t. research and product development. The whole point of this change is to allow me to invest more focus and time, and to take the JeeLabs projects and products further, in fact.

PPS. Following the advice of some friends I highly respect, I’m making this last weblog post open-ended: it’ll be the last post for now. Maybe the new plans don’t work out as expected after all, or maybe I’ll want to reconsider after a while, knowing how much joy and energy this weblog has given me over the years. So let’s just call this a break, until further notice :)

Update Dec 2013 – Check out the forum at for the latest news about JeeLabs.

Summer Break

In News on Jul 1, 2013 at 00:01

It’s that time of year again: 1st of July, and time for me to take a break.

Just as last year, this is going to be my last post on this JeeLabs weblog post for a while – two months to be exact. This isn’t so much about going on holiday (nothing planned yet, other than a few short trips) as it is about performing an internal reset.

The past year has been mostly about taking a new direction in software (by which I mean Node.js and the Dive Into JeeNodes series) – not the embedded Arduino stuff), and about exploring numerous electronics and software topics – a.k.a. Physical Computing.

Speaking of which, yesterday’s post was a good example of what I hope to keep up for a long time to come: introducing electronics and mixing it with embedded microcontrollers to show just how easy it is to tie the two fields together, and to keep on enticing everyone who comes across this weblog to explore, learn, tinker, and play with this stuff. It’s all very low-cost, it’s wide open to make tons of new ideas happen, and there is an immense body of knowledge, experience, and open source software + hardware available to anyone with some spare time, a healthy dose of curiosity, and an internet connection.


There’s a lot to be done beyond what I’ve been dabbling in here at JeeLabs. The field of wireless communication has only just started for the home and the hobbyist. There’s an explosion going on w.r.t. small affordable Linux boards, which take Physical Computing to totally new levels of capability. And there is a huge need to find easy and enticing entry paths into all this, if you ask me. The more there is to learn, the more we need to come up with ways to help people “find their way in”. The RoboCup 2013 event (which will be over by the time you read this) has shown that there is a great opportunity to expose kids of all ages to technology. From hundreds of cheering cardboard FanBots all the way to amazing self-organizing teams of autonomous “Middle Size League” football-playing robots.

The future has only just begun. What an amazing times we live in!

Second bit of news is that it’s time to kick off a summer sale in the web shop once again. And as in previous years, the following discount is for existing JeeLabs supporters, i.e. it can only be requested if you have ordered products from JeeLabs in the past:


And while I’m at it, let me list all the key dates for this period, here at JeeLabs:

  • July 1st – weblog paused and summer sale kicks off
  • July 31st – sale ends at midnight, 0:00 CEST time
  • September 1st – daily weblog resumes

Due to the fine efforts by Martyn Judd & Co., the shop will remain open throughout the summer break, with fulfilment continuing as before from the UK Center in Cambridge. The staff level will be somewhat reduced during August, but we will nevertheless attempt to keep up the regular flow of sending your packages promptly.

There is also a summer sale at Modern Device, but note that since the shops are separate and independent entities, we cannot extend the same offer across the shops. Please check the shop you have purchased from in the past to see what’s on sale.

If you’re looking for geek stuff to do this summer: check out the chronological index of this weblog, maybe there is something that interests you, somewhere in those past 1,364 posts?

Anyway: thank you for all the interest, comments, discussions, tips, and appreciative emails – I’m honoured by everything that’s happening around JeeLabs and looking forward to lots of new ideas, developments, sharing, and products – starting again on September 1st.

Have a nice summer (or winter, on the southern hemisphere)!

Energy Hack June 15 in Berlin

In News on May 30, 2013 at 00:01

For the German readers… got this announcement in which might be of interest to you:

[...] It will be a day of hacking the open energy data by Berlin’s main energy provider and exploring hardware hacks to manage energy consumption in one’s own household. You can find all the necessary info on

The day will be mostly in German, but since the topic is global and all Germans speak English, we hope to make everyone feel at home.


Some more details, now “auf Deutsch”:

Am Samstag, 15. Juni, veranstaltet die Open Knowledge Foundation Deutschland e.V. in Berlin einen Hackday zum Thema „Energie der Zukunft“, zu dem wir euch alle herzlich einladen.

Ziel des Energie-Hackdays ist es, die abstrakten Themen Stromversorgung und -verbrauch besser greifbar zu machen und Verbraucher zur effizienteren Nutzung von Energie anzuregen. Gemeinsam mit Programmiererinnen, Softwareentwicklern und Open Data-Enthusiasten wollen wir mit den Daten des Berliner Stromnetzes experimentieren und Anwendungen verschiedenster Art bauen. Besonders freuen wir uns über Hardwarehacks, die zum Stromsparen anregen oder sich auf andere Weise mit dem Thema Energie auseinander setzen.

Zur Verfügung stehen unter anderem Echtzeitdaten zur Last und Erzeugung in Berlin sowie durchschnittliche Verbrauchsdaten von Haushalten, die ihr als Open Data in den Datenkatalogen des Netzbetreibers und der Stadt Berlin findet. Außerdem haben wir elektronische Zähler zum „Selbstablesen“. Falls ihr Anregungen oder Ideen für weitere interessante Datensätze habt oder Material zum Hardware-Basteln braucht, das ihr nicht selbst mitbringen könnt, kontaktiert uns!

I won’t have time for it, alas, but if you’re interested, go to

New series – What If?

In Hardware, News, Software on Apr 23, 2013 at 00:01

Questions are very useful: “what would happen if…” is the foundation of science, after all.

Conjectures and Refutations is a famous book by the late philosopher Sir Karl Popper. I could not possibly summarise it (heck, I haven’t even read it), but what I take away from what I’ve read and heard about it, is that theories can be judged on their predictive value. A theory in itself is no more than an intellectual exercise, but its real value lies in being able to apply it to what-if questions. The stronger a theory, the better it should predict outcomes. The way to “refute” a theory, is to come up with an example where it fails. Rinse and repeat, and you’ve captured the essence of science.

Want to predict what will happen when you place a 100 Ω resistor across a 9V battery? That’s easy, given the proper theory: take Ohm’s Law (i.e. a theory which has stood the test of time), and apply it – a current of ≈ 11 90 mA will flow. Actually a bit less due to the internal resistance of the battery, which goes to show how strong theories can be refined further, leading to even more accurate predictions.

The what-if question is a great way to experiment, especially in electronics and electro-mechanics, because it lets you be prepared and avoid silly (and sometimes catastrophic) outcomes, such as a damaged component, a harmful burn, or even an explosion.

This approach lends itself to all sorts of practical questions:

  • What if I short out a 3x AA battery pack?
  • What if I connect my chip the wrong way around?
  • What if I have to use a 12V power supply instead of 5V?

But also issues as varied as:

  • What if I omit a certain component from my circuit?
  • What if I unplug the Raspberry Pi without shutting it down?
  • What if I wanted to use HouseMon in combination with MySQL?

Properly phrased, what-if questions are essential for practical experiments, and – by extension – also the key to building useful circuits and automated installations.

A useful variation of the what-if question is to help predict “bad” outcomes and estimate the risk of an experiment, such as: can shorting out my power supply cause real damage?

Starting tomorrow, I’m launching a new series on this weblog, titled “What-If Wednesday”. As far as I’m concerned, it can run as long as there are interesting questions I can answer, so please feel free to suggest lots of topics in the comments below. These weekly posts will be tagged What-If, and I’m also setting up a new wiki page to collect them all.

Sooo… please help me out folks, and send in some nice what-if questions!

Winding down

In Musings, News on Apr 22, 2013 at 00:01

The JeeDay 2013-04 event is over.

I would like to warmly thank the 40 or so people who attended on Friday and Saturday. It is clear to me from the kind follow-up emails that the event was appreciated by many of you and I really hope that everyone got something useful and stimulating out of this.

Allow me to also thank the “anonymous sponsor” at this point for funding the venue, the coffee and drinks, and Saturday’s lunch. I’ve passed on your and my appreciation, and it has gratefully been accepted. As several people have pointed out, this whole concept of an anonymous sponsor is really a contradiction in terms, so let’s all just cherish the fact that philanthropy (and mystery) still exists, even in today’s western societies.

This is probably the point where I’m expected to write sentences full of superlatives, self-congratulatory remarks, let’s-conquer-the-world type of pep-talk, congratulations for the speakers and their choice of interesting topics, all sorts of grandiose plans, and where I’d also describe how stimulating all the discussions on the side turned out to be.

I could, and it’d be true. But I won’t…

Instead, I’d like to give this a somewhat different (personal / philosophical) twist.

We’re focused on success. We crave rewards. We seek recognition. So when something good (for some definition of “good”) happens, we want to take it further.

Again. Better. More.

Yet to me, that’s not what JeeDay was about. Sure, we could do it again. In fact, I’d love to and I’ve even sort-of committed to organising another JeeDay a year from now. We’ll see.

But to me, JeeDay is not about the next step or some future trend. It’s about this event we just had. Some 10 talks from people describing what they like to do in their free time. That’s quite a special situation, when you stop and think about it: here we all are, a few dozen geeks with a common techie interest, and this what we choose to spend our time, our creative energies, and our money on. We could do anything, yet this is what we want to do. In. Our. Free. Time.

Now of course, everyone’s reasons will differ. But to me, it’s pretty amazing: there’s rarely a financial reward (heck, it usually costs money!). There’s often not much recognition. These are not TED talks, we’re not working on some high-visibility successful project and showing the world. We just tinker in private, we come up with stuff, we learn, and we like doing it.

In my view, this is about the top two tiers of Maslow’s hierarchy of needs:


The basic idea being that you can’t really get to focus on the levels above before the levels underneath have more or less been covered.

This is – again, in my perception – not about success, and probably not even about peer recognition, but about the intrinsic fun of discovery, invention, creation, and problem-solving. And about finding out how others deal with this. It’s no accident that most of it happens as open source, either: open source (hardware + software) and sharing is what floats to the top when the intrinsic puzzles and their solutions dominate.

In a world where so much is about ownership, money, and time, I think that’s precious.

I hope JeeDay has helped you find and follow your passion. Everything else is secondary.

PS. The mystery topic in my presentation was JeeBoot – more to follow soon.

See you in Houten!

In News on Apr 19, 2013 at 00:01

Psst, did you know? We’re getting together…

Here’s the location, right next to the railway station:


If you prefer to come by car, set your driving directions for Kamillehof in Houten to find a parking spot (or use the parking garage on the other side of the railway). Note that there is essentially only one way to get there:


Any attempt to drive differently will probably lead you to a bicycle path or one-way street…

JeeDay flier

Bring your pet projects (not the pets, please), bring your curiosity, and bring your energy. Let’s have some techie fun, eh?

Electro:camp 13.04

In News on Apr 17, 2013 at 00:01

As if one event is not enough – here’s a reminder for another one coming up soon:

This the next one in a series of bi-annual meetings, from people in Germany, Belgium, the Netherlands, the UK, and beyond – this time in Kaiserslautern @ the Fraunhofer institute.

See the wiki for further details. Don’t forget to register if you wish to attend.

As I see it, Electro:camp is more focused on electricity metering and monitoring, whereas JeeDay – which has yet to define itself, clearly – will be more of a “maker/hacker” style event with focus on DIY home projects, low-power wireless, and electronics as a hobby.

JeeDay next Fri+Sat

In News on Apr 16, 2013 at 00:01

(whoops, this went out one day earlier than planned… before it was ready)

Just as reminder, here’s the announcement (as you can see, I’m no graphics designer):

JeeDay flier

And this is the draft time schedule for the entire event:

JeeDay 2013-04

For more information, see the JeeDay wiki page.

PS – The is no pre-registration, everyone is welcome. The venue is large enough to accommodate some 25 people on Friday and about 35 on Saturday, which matches more or less the interest on the original list.

Energy savings…

In Musings, News on Mar 31, 2013 at 00:01

Here’s a view of the solar energy production earlier this week here at JeeLabs:

Screen Shot 2013-03-26 at 18.49.36

Best day so far … 19.3 kWh in one day: that’s some 2.5 x our average daily consumption!

This graph was made with HouseMon, which is still in the early stages but I’m viewing it on a daily basis – the Status and Graphs pages are already quite practical. Then again, it’s a constant reminder that the progress of this project is considerably slower than I had hoped when I started out. One reason for that is that I’m still hesitant to make some major design decisions – mostly because I don’t have enough experience and don’t feel confident enough with Node.js and CoffeeScript yet. So many things still feel awkward :(

Speaking of insufficient progress… it’s time to switch off:

wallpaper power symbol green

(image by TheBigDaveC, as found on this site)

I’m going to take a brief break, and interrupt this daily flow of weblog posts for a while.

It has happened before, and it will happen again: I want to clear my head and focus on some projects which take a bit more concentration than I seem to be finding these days.

But no worries: this daily weblog will resume before JeeDay (April 19 + 20), so there will still be enough time to get the latest info and news out to you.

Soooo… see you then, and more importantly: see you there !

(Pssst… in case you haven’t seen this… let that nano stuff inspire you… pretty amazing!)

Issues on GitHub

In News, Software on Feb 26, 2013 at 00:01

Since doing more and more with GitHub, I’ve been getting increasingly impressed with the features and workflow of that website. One of the things which really turned me around, was its issue tracker. This is already in use on projects such as EtherCard, as you can see:

Screen Shot 2013-02-19 at 22.39.00

The way things are implemented, including mail integration, keyboard shortcuts, and the fact that issue pages update in real time (making them little real-time chat environments) has convinced me that it really is the best place to deal with these things for all JeeLabs projects. This means I’m also not going to enable issue tracking in Redmine after all.

I’m not too concerned about lock-in, because all source code, its history, and even the entire issue tracking dataset is available for download from their site via a REST API.

I’ve also been using GitHub issues quite a bit for HouseMon lately, and have just started using its “milestones” feature, to help organise and plan the pile of work ahead:

Screen Shot 2013-02-19 at 22.20.22

Sooo… if you have a problem with JeeLib, Ethercard, etc. and want to report a bug, feel free to do so on the GitHub site. This doesn’t replace or interfere with the discussion forums on the JeeLabs “Café” in any way, as these continue to be the place for discussion and general questions and support. But for obvious bugs and clear-cut enhancement requests, GitHub is the place to be from now on…

As some people have started to discover, GitHub is also the fastest way to get patches and new features implemented – the mechanism for this is called “forking” and “submitting a pull request” (me pulling your changes into the official libraries, that is).

Here is a nice write-up about the process, written by the developers of “ThinkUp” – but it really applies to any project on GitHub.

As for release versioning, I’ll be using this approach for HouseMon from now on. This means that if you want to follow along and see the latest changes, you need to enter git checkout develop (once). The “master” branch will only update on the next release.

PS. Still struggling with all the terms and “features” of git. Thanks to @tht on the forum, I’m looking into SourceTree (for Mac), which acts as GUI wrapper around git commands, but I can’t say the coin has dropped quite yet. Things like merge vs rebase sound logical, but I’m sure I’ll get it wrong several more times before getting the hang of it…

Solar at last

In Hardware, News on Oct 20, 2012 at 00:01

As mentioned recently, last step was getting the SMA 5000TL inverter and hooking it up:

DSC 4200

DSC 4203

Here’s the before-and-after shot of the hookup:

DSC 4190

DSC 4192

Three pulse-counters to help me measure what comes in, what goes out, and the induction stove (measured separately). Still a minor wiring error, but that’ll be fixed soon.

So that’s the end of the story for now. Let the sun shine!

Elektro:camp October 26 and 27

In News on Oct 10, 2012 at 00:01

A year has passed, and it’s time for a get-together again, in Leuven, Belgium this time:

Elektro camp 2012 10 final

What is it?

Elektro:camp is a place where geeks meet to talk about smart metering, smart homes, smart grids, and smart ideas. Everything in and around the house related to electricity and electronics, really. Oh, and software.

This is a “barcamp” so there’s no fixed agenda: we make it up as we go, and we all present our ideas and discuss the ideas of others. Trust me, if things go as they did last time, then we’ll be scrambling to find enough time to go through everything that pops up.

Wanna have lots of fun with a bunch of geeks? Wanna show what you’re working on? Wanna present some new ideas? Wanna meet up in person? Be there!

It’s at the Faculty of Engineering this time, and since it’s all done as volunteer effort, please register soon if you’re considering joining us. For questions and other info, please contact Bart Van Der Meerssche.

Looking forward to meet some of you in a couple of weeks!

Shop news

In News on Oct 2, 2012 at 00:01

How does this sequence continue?

    GG TW TK SG .. .. 


    MT CY

Get it? Think country codes…

And those last two (Malta & Cyprus) bring the total to 50 countries where JeeLabs Shop has delivered products. Woohoo! Thank you John & Andreas for reaching that milestone – welcome to the expanding community of JeeLabs experimenters!

(and thank you Martyn, for spotting this factoid)

Now that we’re on this topic anyway: the shop has just been upgraded to accommodate the new 21% VAT tax requirements in the Netherlands, effective as of October 1st. Death and taxes, as they say… the two inevitabilities in life!

After two years of total stability, we’ve had to raise the price on some items, to match costs and keep those ever-changing US$ exchange rates in check, but the good news is that all the major items such as JeeNodes, RBBB’s, and USB BUBs remain at the same level as before. This is where (modest) economies of scale start to kick in, so we’re not changing one bit of what has been working out so well.

Another point I’d like to single out here, is that Martyn and Rohan Judd have been doing a truly phenomenal job of steering a major shop transition over the summer into a pretty smoothly-running operation again – as it’s now all done from the UK. With a tip-of-the-hat to you fella’s, for making this happen in the best imaginable way – cheers!

There is more change cooking, but for the moment the only change you will see is that the shop’s email is now coming from order_assistance at jeelabs dot org. This address is from now on also the best place to get in touch, to make sure no message goes by unseen. Whether it is an inquiry about packages, questions about delivery times or problems with the supplied goods, we’ll take care of it. Yes, including me – I’m not going anywhere :-)

Oh, and then there’s that second disruption I mentioned a few days ago: the Café + Wiki at have now been replaced by the new Redmine 2 system. The original wiki and doc pages can still be reached at “”. For now.

Note that the forum is not affected. It’ll be switched over to Redmine later this year.


In News on Sep 28, 2012 at 00:01

There are a couple of disruptions imminent regarding the JeeLabs web sites:

  • First one is a VAT increase in the Netherlands, starting October 1st. This will affect the shop.

  • Second one is the switch from Redmine 1 to Redmine 2, this will affect the café (docs and wiki).

  • Third one is a transition / migration from Drupal to Redmine – this will affect the forum.

Let me assure you that I hate each of the above changes at least as much as you do. Probably more.

But there’s no way around it. The VAT increase from 19% to 21% is a legal requirement, of course, so it’s both necessary and needs to happen on a specific date. A few days from now, that is. More news on that coming.

The switch from Redmine 1 to Redmine 2 was also inevitable, in the long run. I’m quite happy with Redmine as a system, but the current 1.0.1 setup has been out for two years, and I haven’t ever been able to easily update it. Yuck, yuck, yuck. In the end, the only way out was to wait for a solid 2.x release series, which also happens to come with a far better upgrade mechanism.

But instead of doing some sort of 1.x -> 2.x conversion for a range of projects in Redmine 1 (some public, but also several private ones), I’ve decided to just start over. With the help of a couple of people (thank you Steve, thank you Myra), just about all the main content of the café has now been transferred (converted, in fact).

Except the API documentation – this hasn’t been migrated, because I’ve decided been convinced that maintaining API documentation in Doxygen is a far better long-term solution (thanks Jasper). So instead of setting up wiki pages for that, all the JeeLabs libraries can now be extended with comments for Doxygen to generate nice docs from – which I intend to publish as part of the new “” site (for now, you can generate the JeeLib docs yourself, again thanks to Jasper’s check-ins).

The new Redmine website has been around for some time now (at, but largely unexposed.

On October 1st, I’m going to take the plunge, and replace the current site with the new one. This will probably break most URLs out there.

(Did I mention how much I hate these changes?)

Note: to avoid losing essential info, the current site will be moved to “”, for reference. So if you can’t find what you’re looking for, you can prefix the url with “oldred.” and try again.

The fact is, that I’ve not made enough progress in the current situation for some time now, and the only way to get there is to break everything first, and then quickly try to repair the most harmful damage. Evolution just doesn’t cut it for me in a case like this, apparently.

Apart from the URL breakage, there are some additional horrid consequences:

  • To participate (submitting bugs, editing wiki pages, etc), you will need to register as new user again. To make matters even worse, I’m not enabling auto-registration to keep spammers at bay. So new registrations will not be instant.

    (Did I mention that I hate spammers even more than these disruptive changes?)

    Please use the same user name for registration as on the forum (I’ll explain why in a moment).

  • I’m dropping Markdown as wiki formatting language, and switching to Textile. This format comes from the Ruby world and is considerably better supported by Redmine (which is implemented using Ruby On Rails). The good news is that Textile formatting is very similar to Markdown for simple things, and much better at supporting more complex features (such as tables, colours, and even CSS styles).

The third disruption is probably going to cause the most frowning and cursing, but it too is becoming inevitable. Some time later this year, the forum will be migrated to Redmine as well. One reason is practical, in that Drupal admin is too much of a burden (for the three of us sharing the burden: thank you Martyn, thank you Steve again). And since I’m not going to start using it for more tasks here anyway, it really bothers me to have to keep a VM running with 1 GB RAM allocated to it.

This is the reason why registration on the new Redmine site should be done with your existing forum name, where possible: it’ll become a forum as well, once that third big switch is flipped.

But there are also advantages to this forum migration. A major one of them is the nice integration we gain by having forums, issues, source code browsing, and wiki pages all in the same system. Something I’ve always been looking for, and frankly Redmine 2 has been moving in the right direction for some time now.

And lastly, note that “” will keep a copy of all the forum discussions, so those URLs will in fact not break – that forum will merely become read-only (preferably using a static copy, if I can figure out how).

Anyway. Major disruptions. I hope you’ll bear with me as this takes place, and that you’re willing to help out and pinpoint any problematic and painful spots this leads to. First there is trouble, then we can fix it. There’s no way back – so let’s at least try and make the way forward as effective as possible.

Once the big trouble spots have been identified and resolved, I can move forward on the documentation side of things again (hardware as well as software). That too has been long overdue. Jeelabs deserves better. Open source deserves better. And you deserve better from me. A lot better.

Now the good news: the new Redmine setup (currently at has recently been given a major makeover (thank you David), bringing it close in style to the daily weblog. Same logo, same fonts, same looks.

The best news though, I’m sure you’ll agree, is that the daily weblog isn’t going to change!

Hello, Laser Cutter!

In Hardware, News on Sep 17, 2012 at 00:01

Yep, it has finally happened… it all started in July, when I got this (without the electronics board) and this (called the LaOS board).

The laser arrived like this:


This summer, a couple of early adopters in the Netherlands got together to figure out all the pesky little details that come up when you’re really just in pioneering mode. Make no mistake: this thing is far from ready for mainstream use. The laser itself is quite nice and ready to go, and definitely workable as far as all the mechanics go. But the electronics and software are still work-in-progress (I’m using the VisiCut software – which includes a driver that talks directly to the laser’s firmware over Ethernet).

Nevertheless – early as it may be, the total cost is less than €1,500 and you end up with an A4-sized laserable workspace which can cut up to 5 mm wood panels and 6 mm acrylic (engraving is more involved, but getting there). One of the first things we tried was this:

Image 1

Sure enough, the circle is a snug fit and turns perfectly. Excellent alignment!

I’ll describe a few more details of this setup in the coming weblog posts, but also want to point out that you too can end up with such a laser cutter (just make sure to arrange for ventilation – you’ll quickly get very tired of the burning smell and fumes).

There’s a project by the designers of the replacement electronics, called LaOS (Laser Open Source) – and it’s definitely the best place to go right now if you want to find out what’s going on. Warning: the site is currently undergoing a messy transition to a new wiki – I’ve helped out a bit and am sure they’d love to see more people join in the effort of making this thing more practical for the non-hacker crowd.

One little gotcha: these 35 W laser cutters are produced in China and then tested/resold by a company in the UK, and they are really large and heavy. Having one shipped from the UK to you is fairly expensive, because of the delicate glass laser tube (several hundred Euro, most likely). We got around that by getting organised and doing a “group buy”, with one person actually volunteering to go to the UK, load his car up with a bunch of laser cutters, and driving back (!). Still pricey, but less so, and I think the UK vendor is in fact willing to make arrangements when enough units are being purchased and shipped at the same time. Anyway – it’s an aspect to keep in mind.

But oy, oy, oy, this personal fabbing is fun :)

Shoppety shop

In News on Sep 3, 2012 at 00:01

Short post, with big consequences for me…

As you might have noticed, the Jeelabs Shop has been kept open and operational during the summer break. The reason for this, is that Martyn and Rohan Judd have set up what is now essentially a fantastic fullfilment service for JeeLabs.

As a result, this welcome message on the shop’s home page is now more or less permanent:

Screen Shot 2012 09 02 at 23 45 26

The limit for free shipping has beeen raised somewhat, due to the higher cost of shipping to “mainland” Europe from the UK. The other major change is that you need to use the indicated email address to make sure your message reaches me and all people involved.

Note that I am out of the loop for day-to-day order processing, but not out of the loop in any other way!

There will be more changes, most of them probably behind the scenes, as we work out all the details of doing business this way. As far as the shop is concerned, the orders are still placed in the Netherlands, and I remain as before fully responsible and accountable for everything that happens – both good and bad. VAT processing (and VAT exemption for EU-based business outside the Netherlands) will also remain exactly as before.

I am quite confident that this change will allow me to spend more time on the R&D side of things regarding all current and future JeeLabs projects.

Which, dear reader, is – and remains – my main motivation for doing all this, of course.


JeeLabs logo

In News on Sep 2, 2012 at 00:01

Tada! I’m really proud to be able to present the JeeLabs new-and-official “look” to you!

Here is the new logo for JeeLabs – nicely distinctive and with a little wink towards battery-powered electronics:

Screen Shot 2012 09 01 at 22 19 14

As you can see, this has been incorporated into the weblog, as header and as “favicon”.

I hope you like it.

The proportions and font used for the “JeeLabs” text in the header above are still work-in-progress. In fact, I just used the Trebuchet MS font with smallcaps for now, because it sort of resembles the letters in the logo. If you have tips or suggestions for this, let me know…

One more announcement tomorrow, then “regular” JeeLabs posts will resume – promise!

Summer break

In News on Jul 1, 2012 at 00:01

Ok, time to sign off for the summer break. This weblog will be off the air until September 1st – same as last year.

But unlike last year, the shop will stay open during the break: Martyn and Rohan Judd will be taking over all JeeLabs shop duties from the UK this summer. We’re making a range of preparations to get everything going smoothly, but please note that there will be some “reduced availability” issues during this time – i.e. a few more items out of stock than usual, and occasional delays while trying to prepare packages and get things out the door.

It’s been yet another truly fascinating year here. Somewhat fewer new products out the door than I would have wanted, but also quite a bit more work behind the scenes to make sure this all remains focused on fooling around with physical computing, wireless networking, and ultra-low power computing. And even though there has been another unplanned break early this year, things are actually starting to work out a lot better these days. As I’ve learned after over 1000 posts, the trick is to stay ahead of the weblog by a comfortably large margin, instead of having the daily publishing schedule dictate how to spend my time and my energy. This summer break will give me an excellent opportunity to relax, re-focus, and then re-launch into the next yearly cycle – IOW: onwards!

Until then, I’ll leave you with a view of one of the more chaotic corners of the JeeLabs work area:

2012 07 02 09 34

If physical computing – or even just technology in general – is your thing, then maybe some of these past 1075 posts will encourage you to follow your passion, nurture your curiosity, cherish your fascination, challenge your boundaries, and … be creative! Because there is infinite fun in creating and in learning from what others create.

To be continued in September. Have a wonderful time!

Note – Please send all questions about the shop, payments, and shipping to email address order_assistance at jeelabs dot org during the summer break – that way it will reach both the people handling the shop and me. Note also that I will be reading email only once a week during this period.


In News on Jun 20, 2012 at 00:01

As you may have seen in a number of discussions on the forum (such as this one), things are still in flux w.r.t. documentation of software / libraries / hardware coming out of JeeLabs.

I’ve been agonizing for ages about this. It’s a recurring theme and it drives me up the wall about once a year.

Like with so many things, ya’ can’t get very high (or far) if you keep changing shoulders to stand on…

The good news is that the wait is over. All documentation and collaborative editing is going to be done with Redmine, the same system which has been driving the Café for some time now. But a few things will change:

  • Redmine has now evolved to version 2.0.3, and I’ll be using subversion to easily track updates
  • page formatting will switch from Markdown to Textile plus Redmine’s own extensions
  • anyone can register to participate, but the process involves an administrator (goodbye, spammers)
  • the system supports generating PDF’s, so we can have good web docs and good paper-like docs
  • better support for page hierarchies and automatic page lists, i.e. more high-level structure

Also, I found an excellent theme for the wiki, which gives the whole thing a clean look and nice layout. Like so:

Screen Shot 2012 06 19 at 22 30 35

Clean, minimal, and compatible with all modern browsers, as far as I can tell.

But this isn’t about good looks at all, really. That’s just an enabler, to finally make it worthwhile to pour tons and tons of my time into this.

And now that I have your attention…

The above has been set up, but it’s very, very early days. Things may get (slightly) worse before they get better – i.e. I’m not going to do much more maintenance on the current Café pages at – neither the hardware pages, nor the software documentation, nor any of the other wiki pages or user-contributed info.

The reason to announce this here anyway, is that I want to make a really serious effort to get it right. I would like Physical Computing software and hardware such as from JeeLabs to be maximally fun to explore, easy to get acquainted with, fully open to adopt and tweak, and truly, truly, truly effective and practical. No fluff, no nonsense, but a rich resource which improves over time.

I love writing (heck, 1000+ posts ought to have made that clear by now) and as I said, I’m willing to pour lots of time and effort into this. But I can’t do it alone. You can help by telling me what sort of info you need, where you’re coming from, what style and structure would work well for you, and you can help point out the errors, the gaps, the omissions, the mistakes… or anything you don’t agree with and consider substantial enough to bring up.

You can of course also help a lot more than that, by participating in this initiative to get a really good collaborative documentation site going (I’m willing to beg on my knees, bribe you in some innocent way, or pile up the compliments if that helps). Everybody is busy, but I think there is value in trying to coordinate efforts like this.

To put it all in perspective: this new documentation site is not “my” site (other than providing the infrastruture). Even though I’ll probably be one of the main contributors, it’s not anyone’s site, in that nothing on it should be written in first-person form. No I’s and me’s to wonder about who said what. It needs to become everyone’s site, a live knowledge base, with full and honest attribution to everyone who volunteers to get involved.

Let’s get the focus on audience right. Let’s get the structure right. And let’s get the content right. In that order.

Here’s the bad news (yeah, I know, should normally have started off with this) …

No spotlights on this endeavor for the next three months. No fame. No riches. Only blood, sweat, and tears.

This weblog post will remain the only one to draw attention to this documentation challenge. I’m inviting you to participate and help shape things. I hope some of you will find a suitable amount of time, right now or later on.

Note that I haven’t mentioned “code” until now. That’s not because code is irrelevant. On the contrary – part of this work will be to write new code, redo things done so far, and if possible even to “lead by example”. The same goes for technical documentation and for tutorials which can go far beyond just telling what the code does. And for automatically generated documentation from comments or other text files. It all has a place.

But it’s easy to get swamped by it all – as I’ve been for so long – and never reach a practical point. Best thing for me to do now, is to try and pick a single direction for documentation and run with it. You’re welcome to tie your own interests and efforts into this – I’m sure we can figure out ways to make things work nicely together.

One last point – this isn’t really limited to software or hardware from JeeLabs. To me, this whole Jeelabs thing is just an umbrella to go off and play with “Computing Stuff tied to the Physical World”, wherever that leads to. I use this as basis to try and stay focused (hah!) and keep aiming in a somewhat coherent (hah again!) direction.

Wanna help make the above happen? Email me some thoughts and I’ll set up editor access for you.

Discount month

In News on Jun 1, 2012 at 00:01

It’s that warm summer time of year again – at least on this hemisphere…

Time to kick off a new discount month in the JeeLabs web shop

Screen Shot 2012 05 31 at 08 43 09

During the month of June, everyone who has previously purchased something from the JeeLabs shop (i.e. before June 1st 2012) can use discount code “JEE2012GO” to get 12% off all items.

And while I’m at it, let me list some other important dates for this period, here at JeeLabs:

  • June 1st – summer sale kicks off with this post

  • June 30th – sale ends at midnight, 0:00 CEST time

  • July 1st – weblog is suspended during the summer

  • July 15th – shop enters “summer fulfillment mode”

  • August 16th – shop resumes normal operation

  • August 31st – daily weblog resumes

Most of these are more or less the same as in the past years. The 2-month summer hiatus on the daily weblog gives me time to recharge and put things in perspective, and gives you some time off to enjoy other activities :)

The summer fulfillment mode is new. I’m currently making arrangements to keep the shop open this time, by having new orders and support handled by someone else. More details will follow once everything is in place.

Anyway – now you know what’s coming as far as JeeLabs and yours truly is concerned for the summer period.

TD – LED flashlight

In Hardware, News on May 22, 2012 at 00:01

Welcome to the Tuesday Teardown series, about looking inside the technology around us.

Today’s episode will be a short one, it’ll become clear why halfway down this page…

This is a little bargain LED flashlight, nothing to it really:

DSC 3228

Three AAA (not AA) cells, a toggle button, 24 + 4 white LEDs, and that’s it. Press the button once, and the 4 LEDs on the side turn on, press again to light the 24 on the top, and again to turn it off.

Quite a bright light BTW. The 4 LEDs draw 190 mA, with 16 it rises to 270 mA. That’s perhaps 4 hours of use with 16 LEDs before the batteries run out.

The circuit is as ridiculously simple as can be – one 4.7 Ω resistor and a switch:

DSC 3229

That “metal” reflector is actually plastic with a chrome finish. The PCB is one-sided, no doubt to lower the cost:

DSC 3230

(it won’t take much bending to create a short with that top wire!)

Using Ohm’s law (V = I x R), we can deduce that the LED’s forward voltage is 4.5 – X = 0.190 x 4.7 – in other words, X = 4.5 – 0.190 x 4.7 = 3.6V. Note that the light intensity will vary considerably with battery voltage and that this lamp won’t work at all with 3 AAA EneLoop batteries which only supply 1.2V to 1.3V when fully charged.

The reason I’m opening up this trivial little gadget is not to marvel at the deep electronic engineering that went into it, but to show how custom plastics and a custom case makes something quite practical and nice to the touch. The top and bottom have a rubbery feel to them. The bottom has a little plastic hook in it, which can be folded out.

The bigger news today is a bit of a mess, unfortunately.

Last night I decided to upgrade the JeeLabs server from Mac OSX 10.7.3 to 10.7.4 – that update had been out for a few days, worked fine on two other machines here, so it seemed safe to apply the update to the server as well.

It failed.

This server is connected via wired Ethernet, and I usually only look at the GUI via a VNC-like “Screen Sharing” mechanism built into Mac OSX. It works well, because that connection is re-established even when the machine is in an exclusive “Updating…” mode, so you get to track progress even while the system is busy replacing some of its own bits and pieces. No screen needed, even though part of admin interface sometimes uses the GUI.

Last night, the server failed to come back online. Which is a major hassle, because then I have to move it to another spot to hook up a mouse, keyboard, and monitor to see what’s going on. Never happened before.

Trouble is (probably), that I turned the darn thing off forcefully. I knew that all the VM’s had been properly shut down, and I heard the characteristic reboot “pling”, so I thought it was waiting for a GUI response… or something.

Then the trouble started. Hooked it up, did a restart: no go. So I restarted it in recovery mode, and did a disk check/repair of all the disks. Guess what: the startup disk with all VM’s could not be repaired… whoops!

Time to kick my backup strategy in gear. I have two in place: local hourly Time Machine backups to a second drive, and daily backups for all VM’s to the cloud.

To make a very long night story short: the local hourly backups are fine, but they do not include the VM’s (whole-file backups of a VM disk every hour is not really practical). And the daily backups? Well, they are indeed all there – I can get any day in the past 3 months back, for any of the 4 VM’s. Awesome.

But Turnkey Linux does things a bit differently. Very clever in fact: it only backs up the minimum. The Linux Debian packages for example: these are not backed up, but re-installed from some other source. The rest is a well thought-out mix of full and incremental backups, and it all works just as expected.

Except that my VM’s are about two years old now, and no longer the latest base images used by Turnkey Linux. No problem, they say: you can get the latest, and then recover your own stuff on top of that.

So I spent about 6 hours trying to work out how to get my VM’s back up from the Amazon S3 storage. No joy. I can see all the files being restored, but the result is not a working VM. At some point, package installs & updates hang, with either udev restart problems or bootdisk image generation problems.

And now the crazy bit: the JeeLabs weblog + forum + café sites are all back up again (phew!). I restored from Time Machine to a freshly freed disk partition, and restarted the Mac – it’s alive! Right now, the server is running from the new disk partition, but with the 4 VM disk images still on the damaged partition. So apparently they did not get any damage, although the Mac file system structure on that disk seems to be hosed.

I’ll spend some time thinking about how to clean up this mess, and how to avoid it in the future. The good news is that I lost no data – just a lot of time and some hair. Yikes … this really was uncomfortably close to the edge!

The moral: test the backup strategy regularly. It can still break, even when not changing anything!

Update – All systems are “go” again.

Update 2 – Final diagnosis: one of the 2 internal disks was getting too hot, leading to intermittent failure, so it was hardware after all – unrelated to the 10.7.4 software. And it was probably all my fault, because I placed a (fairly warm) router on top of the Mac Mini. I’m going to replace the failed system drive with with an SSD.

Weblog post 1000 !

In Musings, News on Apr 17, 2012 at 00:01

Today is a huge milestone for JeeLabs. This is weblog post number:

Screen Shot 2012 04 16 at 17 15 32


It all started on October 25th in 2008, with a weblog post about – quite appropriately – the Arduino.

Then it took a few more months to evolve into a daily habit, and yet another few months to set up a shop, but apart from that it has all remained more or less the same ever since.

You might have been following this from the start, and you might even have been going through the long list of daily posts later, but there you have it – a personal account of my adventures in the world of Physical Computing. If anything, these years have been the source of immense inspiration and delight. I’ve been able to re-connect to my inner geek, or rather: my inner ever-curious and joyful child. And to so many like-minded souls – thank you.

“Standing on the shoulder of giants” is a bit over-used as a phrase, but it really does apply when it comes to technology and engineering. What we can do today is only possible because many generations of tinkerers, inventors, and researchers before us have created the foundations and the tools on which we can build today. It feels silly even to try and list them – such a list would be virtually endless.

I’m not a technocrat. I think our IT world has done its share to rob people of numerous meaningful and competence-building jobs, and to introduce new mind-numbing and RSI-inducing repetitive tasks. Our (Western) societies have become de-humanized as more and more screens take over in the most unexpected workplaces, and our car trips and train rides are turning us into very selectively-social beings, reserving our emotions but even our respect and courtesy for our families and the people we choose as our friends. Technology’s impact on daily life is a pretty horrible mess, if you ask me.

But what drives me, are the passion and the creativity and the excitement in the field of technology. Not for the sake of technology, but because that’s one of the major domains where cognition and rationality have free reign. You can learn (and reason) all about history, medicine, psychology, or you can invent (and reason about) things which do new things, be it electrical, mechanical, biological, informational, or otherwise. Technology as a source of boundless evolution and innovation is breath-taking, we “merely” have to tap it and put it to good use.

And what thrills me most is not what I can do in that direction, but what others have done in the past and are still doing every day. Learning about all that existing technology around us is like looking into the minds of the persons who came up with all that stuff, feeling their struggles, their puzzles, and ultimately the solutions they came up with. I’m in awe of all the cleverness that has emerged before us, and even more in awe of the thought that this will no doubt go on forever.

It’s really all about nurturing curiosity, asking questions, and solving the puzzles they bring to the surface:

I have no special talents. I am only passionately curious. — Albert Einstein

Here’s the good news: we all have that ability. We all came into the world the same way. We can all be explorers.

If you start doing this early on in life and hold onto it, you’ll never be hungry and you’ll never get bored. And if you didn’t have that opportunity back then: nothing of substance prevents you from starting today!

We live in amazing times. Ubiquitous internet and access to knowledge. Open source Physical Computing. Online communities with a common language. This weblog is simply my way of reciprocating all these incredible gifts.

Learning to program

In News, Software on Apr 15, 2012 at 00:01

As it so happens, someone very recently brought to my attention a site called, which announces itself as simple and as clearly as can be:

Free online university classes for everyone.

It’s a phenominally exciting initiative, second only to the Khan Academy, if you ask me:

Screen Shot 2012 04 14 at 21 23 47

The idea: great video lectures plus exercises to let anyone with (good) internet access learn some major topic really well. You have to be fluent in English, evidently, but apart from that the courses seem to be designed to give the broadest possible group of people access to this new form of – literally! – world-class education.

These guys are serious. With a pool of well-known researchers and teachers and set up to scale massively (the class on Artificial Intelligence which led to all this had over 160,000 people signed up).

For some background info about this project, see these Hack Education and Reuters articles.

The format is slightly different from the Khan Academy in that the courses start on a fixed date and have a fixed duration. So you really have to “sign up” for class if you want to benefit from what they have to offer.

As it so happens, these classes start tomorrow, Monday, April 16th and they will last for 7 weeks.

It looks like there will be a bunch of videos each week, plus some homework assignments, which you can then follow whenever you have time that week. You can enroll in multiple courses, but I’m sure they will be repeated at a later date, so it’s probably best to just pick what feels like a good match right now.

What can I say? IMO, this is a unique chance to learn about modern software programming on many levels. Whether you’ve never built any software or whether you are curious about how some really sophisticated problems can be solved, these six courses cover a breathtaking range of topics.

I don’t know how these courses will turn out, but I do know about some of the names involved, and frankly, I’d have loved to have this sort of access when starting out in programming.

FWIW, out of curiosity, I’ve signed up for CS101. What a nice birthday present.

There has never been a better time to learn than now. This world will never be the same again.

Watchdog kicking in …

In Musings, News on Feb 2, 2012 at 00:01

History is about to repeat itself… With this 954′th post, I have an important announcement to make: I’m slamming on the brakes and taking a one month break away from this weblog.

It’s a bit radical and unexpected, but there is no way around it. This weblog is “driven by passion”, as you will probably know, and the crazy bit is that there’s just too much going on here to keep things going smoothly. I’ve been running behind on shop fulfillment again, and I’ve been running behind even more on answering emails and with helping out on the forum. First thing I hope this will do, is to let me catch up and regain my footing.


In sharp contrast to last year’s emergency stop, this time it’s not so much lack of ideas or lack of energy, but lack of clear focus and direction. The stories I would love to tell need more time – diving into various aspects of physical computing in considerably more depth and detail than what’s been happening on the weblog lately. And it’s not happening because the daily bite-sized cycle is chopping up my attention (even at times when I have enough weblog posts queued up for many days on end – go figure!). And maybe it’s also a hill climbing issue.

For an interesting insight about attention, see Paul Graham’s essay titled Maker’s Schedule, Manager’s Schedule.

I’ve updated the alphabetical and chronological indexes to all the posts on this weblog, to give you something to go through for the coming weeks. It’s a stopgap measure, but it’ll just have to do – and there should be enough to keep you interested and hopefully also pique your interest and keep you excited in the month ahead.

The difference with last year, is that I’m putting a precise cap on the duration of this “outage”: 30 days from now. That’s when this weblog will resume, probably with some announcements and adjustments to its style and format.

Talk to you one month from now!

PS. If you want to learn about electricity, then there are numerous resources on the web. Let me single out one: a 50-minute video by Walter Lewin at MIT about batteries and power (lecture 10 on this page). You can get a deep understanding of what a battery is, why its internal resistance matters, what power is, how heat comes out, what shorting a battery does, and even sparks. It’s a fantastic presentation, and the video was just picked at random!

Happy tinkering in 2012!

In News on Jan 1, 2012 at 00:01

Happy 2012. We each have roughly 5,000 waking hours ahead of us in 2012. Let’s use ‘em – slowly and wisely.

As my contribution to slowing down, I’d like to encourage everyone interested in Computing Stuff tied to the Physical World to deepen your understanding and broaden your experience. So allow me to introduce a little tinkering kit, for those of you who are into ATmega’s and wireless stuff – the JeeNode Block:

DSC 2827  Version 3

This is a recent experiment to fool around with the JeeNode form factor, as a way to create a little self-contained unit which needs no wires to operate. I’m using these blocks to try things out on my desktop (you know, the real physical one), without turning it into a huge spaghetti bowl of power supply wires, USB cables, and test hookups.

It’s basically just a JeeNode, but with a different layout (and RFM12B’s “INT” pin reallocated from PD2 to PB0):

DSC 2829

It’s exactly the right size to support simple low-cost 5×7 cm prototyping boards (lets not call ‘em “shields”, ok?):

DSC 2828

The three headers at the bottom are: 8 digital I/O pins, 4 power pins, and 6 analog I/O pins. The two headers at the top are JeeNode ports 1 and 2. There’s a reset button, an LED, and an FTDI header for uploading new code. The 3x AA battery pack will power the whole thing at 3.6 .. 4.5 V, depending on the type of batteries used. There’s a regulator on board to run at 3.3V, as with all the other JeeNode variants.

Note that this is not a product in the shop. It’s just an exploration by yours truly. And it’s also a one-time offer:

As special encouragement to “start 2012 by tinkering”, I’ll add a JeeNode Block PCB and a prototype board for free to the first three dozen or so people who order a JeeNode from the shop and ask for it. You can then simply re-use all the JeeNode parts for this board (except for the JeeNode’s PCB), since everything is more or less the same. A few missing components will also be included: extra headers, an LED, and the reset button. To take advantage of this offer, select “JeeNode w/ extra Block” from the pop-up list on the order page. Note: this offer is limited to at most one Block per person.

If you come up with a neat project for the JeeNode Block, I encourage you to share your invention on the forum.

Happy 2012. With 5000 hours to discover your passion, extend your knowledge, and unleash your creativity.

Coming back for more

In News on Oct 18, 2011 at 00:01

The JeeLabs shop has always been based on the Shopify service (which I won’t recommend for European shops, because they haven’t got a clue about VAT). It looks nice, and I guess I fell for it before understanding all the implications. So Shopify it is, as far as JeeLabs is concerned. I’ve worked my way around VAT by simply refunding and issuing a VAT-exempt invoice where needed.

Anyway, it turns out that there is now a “customer login” option, which I activated a few days ago. What that means is that whenever you shop at JeeLabs, you now get a choice when checking out your order:

Screen Shot 2011 10 11 at 17 59 07

What that really means, is that you won’t have to re-enter your shipping details over and over again if you decide to come back for more. And judging from the info in Shopify, that’s about a third of all JeeLabs customers. I am very proud of that fact BTW, because in my view a return customer is someone who is genuinely satisfied with what he/she got the first time around. It feels good to be able to follow up.

If you don’t want to leave this sort of info on the Shopify servers, please keep in mind that the only difference is that you get to pick a password for re-using what you’ll need to enter anyway.

In case you’re worried that this information is going to be used (by me or anyone else), for anything but order fulfillment: don’t be. I’m probably far more extreme in my position than you on privacy. I do not track personal details. The internet is a nightmare in that respect as it is. I Really Do Not Track, nor keep logs, nor “forget” to remove logs. I don’t do Google Analytics. I don’t have the Shopify “stats” option. I don’t “visualize” web accesses. All I keep are recent activity logs of my own servers, to be able to figure out problems when needed.

Life’s too short for lots of things – and that includes feeding ego’s and spying on people, IMO :)

But that doesn’t mean you have to suffer and re-enter the same info over and over in the JeeLabs shop, eh?


In News on Oct 11, 2011 at 00:01

Looks like I’ll be participating in this year’s Elektro:Camp (updated link) coming November 4th and 5th. Not sure what it’s all about and how it’s set up – I’ve never been to a “barcamp-style” meeting – but it seems like a good place to be for anyone in the area and interested in hacking on their energy consumption and automation systems at home:

Elektro camp 2011 10 final

If you’re into this sort of thing, consider joining. It’s bound to be fun, and it’ll be great to meet up in person :)

(Groningen brings up lots of memories, I grew up there – most of my primary school time anyway)

Soooo… see you there?

The bits have moved

In News, Software on Sep 3, 2011 at 00:01

There are some changes planned in how things are going to be done around here. I want to streamline things a bit more, and make it easier for people to get involved.

One of the major changes is to move all JeeLabs open source software to GitHub:

Screen Shot 2011 09 02 at 22 01 27

The main reason for doing this, is that it makes it much easier for anyone to make changes to the code, regardless of whether these are changes for personal use or changes which you’d like to see applied to the JeeLabs codebase.

For the upcoming Arduino IDE 1.0 release (which appears to break lots of 0022 projects), I’ve moved and converted a couple of JeeLabs libraries so far:

  • Ports and RF12 have been merged into a single new library called JeeLib
  • the EtherCard and GLCDlib libraries have been moved without name change
  • all *.pde files have been renamed to *.ino, the new 1.0 IDE filename extension
  • references to WProgram.h have been changed to Arduino.h
  • the return type of the write() virtual function has been adjusted
  • some (char) casts were needed for byte to fix unintended hex conversion

If you run into any other issues while using this code with the new Arduino IDE 1.0beta2, let me know.

So what does all this mean for you, working with the Arduino IDE and these JeeLabs libraries?

Well, first of all: if you’re using IDE 0022, there’s no need to change anything. The new code on GitHub is only for the next IDE release. The subversion repositories and ZIP archives on the libraries page in the Café will remain as is until at least the end of this year.

New development by yours truly will take place on GitHub, however. This applies to all embedded software as well as the JeeMon/JeeRev stuff.

The new JeeLib should make it easier to use Ports and RF12 stuff – just use #include <JeeLib.h>.

Note that you don’t need to sign up with GitHub to view or download any of the JeeLabs software. The code stored there is public, and can be used by anyone. Just follow the zip or tar links in the README section at the bottom of the project pages, or use git to “clone” a repository.

To follow all my changes on GitHub, you can use this RSS feed. To follow just the changes to JeeLib in slightly more detail, this feed should do the trick.

One of the features provided by GitHub is “Issue Tracking”, i.e. the ability to file bugs, comment on them, and see what has been reported and which ones are still open. This too is open to anyone, but you have to be signed up and logged in to GitHub to submit issues or discuss them.

For questions and support, please continue to use the JeeLabs forum as before. But if you’re really pretty sure there’s a bug in there, you’re welcome to use the issue trackers (as you know, Mr Murphy and me tend to sprinkle bugs around from time to time, just to keep y’all sharp and busy ;)

And if you’d like to suggest a change, consider forking the code on GitHub and submitting a “pull request”. This is GitHub-speak for submitting patches. Small changes (even multiple ones) are more likely to go in than one big sweeping request to change everything. I’m open for suggestions (in fact, I’ve got a couple of patches from people still waiting to be applied), but please do keep in mind that code changes often imply doc changes, as well as making sure nothing breaks under various scenarios.

All in all, I hope that GitHub will help us all keep better track of all the latest changes to the software, work together more actively to fix bugs and add more functionality. I haven’t heard of GitHub ever going offline, but if it ever does, I’ll make sure that the latest code is also available from the JeeLabs servers as backup.

Update – Here’s an excellent article on how to collaborate via Git and GitHub.

Self-imposed hiatus

In News on Jun 30, 2011 at 00:01

It’s time for a break. And this one was planned :)

But it’s only fitting that today is also a great time to celebrate. Because this weblog has reached…


That’s right. Eight hundred articles on this weblog, published on a daily basis – at midnight Central European Time. About all the fun in physical computing and the electronics, hardware, software, and mechanics surrounding it – collected as a stream of notes describing my adventures in this geeky world of techno-babble.

The posts on this daily JeeLabs Weblog are – by definition – organized as a timeline. Some of it will inevitably be wildly obsolete by now, other parts are timeless and still useful, but if you didn’t tag along from the beginning in 2008, then it might all be somewhat overwhelming – or ridiculously frustrating, depending on your expectations.

There are a few ways to find your way around here. First of all, there are six categories (some of them quite large by now): AVR, Hardware, Musings, News, Software, and the catch-all Uncategorized. A somewhat more fine-grained structure is available through 28 “tags”, shown at the top of each post. There’s an updated listing of them on the intro page.

Another approach to finding your way around here, is to use the Search box at the bottom right of each page. It works quite well, but don’t search too broadly or you’ll get a result with hundreds of posts.

The third place to look for interesting posts is on the “Café“, and especially the pages in the hardware wiki, many of which have a Related Weblog Posts section at the end. I’ve tried to add links to new pages there whenever I could, although there’s still lots of room for improvement.

And last but not least, there’s the forum area, which is getting more and more traffic these days, so it could be a good place to search and ask questions. I tend to participate at least once a day (although quite a bit less in the two months ahead).

If shopping for JeeNodes and other JeeStuff is your kind of thing, don’t forget that the shop will close for one month, starting two weeks from now, and that there’s a discount / sale right now for current customers and contributors. See this page for all the details.

I’d like to thank everyone who in some form or other voiced their appreciation and encouraged me to push further. Techie as it all may be, this weblog is still about people, creativity, and shared passions. Because without all that, there is no point.

Scattered over the coming two months, Liesbeth and I will break away and travel in Europe for a while, and I’ll fill in the rest of this long summer by relaxing, learning, tinkering, experimenting, working on top-secret stuff, and cooking up all sorts of crazy hardware and software for future JeeLabs projects and products.

These daily weblog posts will resume on September 1st.

Until then, for your entertainment, a tale of two worlds: Splitscreen.


Update – Full alphabetical and chronological index.


In News on Jun 15, 2011 at 00:01

Ok, here we go again…

1. The JeeLabs online shop will be closed from July 16 to August 15, 2011.

2. The JeeLabs daily weblog will be on hold from July 1st to August 31st.

3. Sale!

Discount 2011

Each order will be checked, if I can’t figure it out I’ll contact you by email (this may add to the delay).

Update – Similar conditions now also apply for JeeLabs products in the Modern Device – same discount code!

What’s going on

In News on Feb 21, 2011 at 00:01

If you’ve been following this weblog, then you may have noticed that things have been quiet around here…

There are a couple of reasons for this. The first one which triggered it all, was an unfortunate – but ordinary – flu, which swept me off my feet for a couple of days, and then sapped all my energy for a few more. I’m sorry about that, and I’m happy that this is all behind me now.

But there’s more to it than that.

In the beginning, I often had a queue of over a week of weblog posts pending and ready to go out on a daily basis. At that time, the weblog was working out exactly as planned: as a way to report on my adventures in the fascinating land of Physical Computing…

However, over 730 posts later, that buffer has been steadily decreasing, and I’ve often been forced to write a weblog post on the day before its publication. Sometimes this was ready only minutes before the deadline. No fun, and in the past month or two, this ended up happening more and more often. The reporting task became a recurring “what shall I write about today?” challenge. Somewhere along the way, the adventure got lost.

And finally, there’s the web shop, which has taken off much faster than I expected and anticipated. In a way, that’s good: a well-running shop means it provides funding for everything else – from keeping that shop going to being able to start new projects and work on fun stuff. Which is the point of JeeLabs after all.

Except… I’ve been swamped. It’s been a while since I’ve actually been able to “start new projects and work on fun stuff”. And some products added to the shop haven’t gotten the attention they need and deserve, such as writing more software examples and documentation to make things interesting, useful, and practical for everyone. Not to mention some stock problems (there are still a few right now).

One solution would be to “scale up”, i.e. to invest in larger amounts of stock and bring in more people to help with production, packaging, and sales. That’s probably what most people would do when presented with such an incredible “business opportunity”, right?

Ah, but there’s the rub… you see, my goal is not to create a large business and become the boss of something “big”.

Let me tell you a story I heard many years ago…

There’s this guy somewhere on a island, sitting under a tree. He takes a little branch, and patiently carves it into a magnificent little flute. He loves making his flutes, and does it all day long, day in day out. His family and friends enjoy what he’s doing, and everyone’s happy. Then, one day, a visitor comes along and sees him sitting there under his tree, amidst his branches and flutes. He walks over and says: “Wow, that’s amazing what you do. You ought to make lots of flutes, I think you could sell tons of them!”

The guy shrugs, and continues with his flute.

The visitor goes on: “Imagine how much money you could make, and how rich and famous you could become. Man, you could teach others to make these flutes, set up a factory, hire a workforce, and rake in the money! You’d be free to do anything you like. Wouldn’t that be incredible? Now tell me, if you were rich, what would you really like to do most of all?”

The guy looks up and says: “Me? Oh, nothing, just sit under a tree and make flutes.”

I’m not saying I’m exactly like that guy. But close. I want to spend my days exploring new things. And for a while, it’s been happening less and less.

Don’t get me wrong. I do want to share. I do want to encourage others to explore and learn more about all sorts of new and fun technologies. And I do want to continue with Open Source Hardware and Software. The mix of software, hardware, and electronics is absolutely fascinating and oh so worth sharing, and I love to be able to encourage people in those directions. But I don’t want to let the weblog or the shop run my life. My life is not about business, revenues, power, or even success. Heck, it probably wouldn’t be, even if I tried ;)

Dsc 1970

Just for the record: JeeLabs is not going away. On the contrary, I intend to find a way which makes sure that it will last and stay around for many years to come. I want to keep the weblog, as a source of unique posts with 100% original content. I want to keep the web shop going with kits and products which help anyone interested in Physical Computing to try things out, experiment, explore, and learn about it all.

But I need to take care of the inner fire and energy source which drives me. And that requires time to concentrate and the liberty to run off in lots of directions. I’m back into a bit of that right now, and it’s doing wonders for me.

There will be only a few more posts on the weblog this month. I’ll respond to emails and forum posts as before, and I’m committed to keep the shop running in a responsible way, with proper support and doing my best to maintain sufficient stock levels to keep everything listed available for people who want it. In fact, I expect this activity to increase, as more and more larger projects are starting up and several workshops are currently under way. But my focus will be on streamlining things, so I can recover that precious time I need for the longer term health of everything at JeeLabs, including myself.

Take care, and please don’t let the radio silence on this weblog affect your plans and activities. There are lots of old posts to go through which might interest you, just use the search box or go through any of the archived months at the bottom of this page.

When I figure out how to best take this all forward, you’ll be the first to know.

PS. Thanks for all kind emails and encouragements. It makes a very real difference.

2×16 LCD’s – yeay!

In News on Jan 21, 2011 at 00:01

At last… the long-awaited order of 2×16 character LCD’s has arrived!

Here’s what one of those boxes looks like:

Dsc 2418

Many of the pending LCD (+ LCD Plug) back-orders have now been sent out. Yippie!

That still leaves 3 more major items which are holding up a couple of packages: Carrier Board PCB’s, Relay Plugs and RBBB’s. The Carrier Boards are currently in Leipzig and will be here either on Friday, or else right after the weekend. The second item which is really hard to get these days, is the relay used on the Relay Plug – they are expected in about a week. The third item is the RBBB, which has been postponed a bit due to a temporary ATmega328 DIP shortage. This has now been resolved, so I expect to have them in by early February.


It’s strange how these supply issues can make such a difference… looks like I can’t seem to focus on anything substantial when there is a large back-log. Pretty silly, really. Oh well.

Sorry for the interruption, I just had to post about this. Tomorrow will be the third Easy Electrons post about transistors, as promised.

Wiki docs

In News on Jan 10, 2011 at 00:01

I’ve started adding some more info to the new “JeeLabs Café” wiki at

First change is that all products (boards, plugs, etc) now include at least these four files:

  • jlpcb-<NNN>.pdf – the schematic as a PDF page
  • jlpcb-<NNN>.sch – the schematic as EAGLE schematic (binary data)
  • jlpcb-<NNN>.png – the board traces as a PNG image
  • jlpcb-<NNN>.brd – the board design as EAGLE board (binary data)

The files are listed at the bottom of each page mentioned on the Hardware list (a read-only sub-area of the Café).

I’ve also started adding pointers to relevant weblog posts on these product pages. For example, the end of the JeeNode page now looks like this:

Screen Shot 2011 01 09 at 23.01.50

The other addition, is that I’m going to start adding pages focused around specific topics, acting as quick indexes into the weblog. The “stream of conscience” timeline that makes up the daily weblog is probably fine if you’ve been following along for some time and tend to read or skim most new pages fairly regularly. But for anyone stumbling upon this site out of the blue, I suspect that this site is really nearly impenetrable by now.

I don’t intend to the change the style and approach of the daily weblog, because it really is sort of a diary of my adventures through Physical Computing, finding my way around as a maker, and getting to grips with atoms. With all the ups, downs, exciting advances, and dead ends that I happen to bump into at JeeLabs.

But for task-specific and topic-specific access, it makes more sense to have an index to locate specific posts and perhaps annotate them a bit if the weblog entry is incomplete or obsolete by now.

Here’s the new Easy Electrons page on the Café to kick this off:

Screen Shot 2011 01 09 at 22.52.42

This new Easy Electrons index page is mentioned on the main Projects page.

The main page of the Café is still a bit crude, but there are a couple of automatically-generated pages worth visiting to find your way around in the Café, eh, I mean wiki:

Note also that the short URLs printed on all the pcb’s and on the package labels have been adjusted to point to pages in the Café. So when you type into your web browser, you’ll see a page which tells you that it’s a JeeNode v4, provides some info about it, and mentions that there is now a newer version.

I haven’t filled in all the older versions with full details yet, but for all current products, that two-letter-plus-a-digit code will always get you to the latest information in the Café.

Is everything perfect today? No… not by a long shot. But I hope this’ll let us move in that direction.

Site changes

In News on Dec 25, 2010 at 00:01

Two small changes here at JeeLabs. Well, small for you, if I did my homework properly…

First, the domain has been migrated to the new server, now that the new internet link appears to be stable.

This change should be mostly transparent. Same content, same format, same “content provider” as before, everything has been transferred as is.

The server and the internet link are quite a bit faster than before. Both are currently under 10% utilized, and should be able to handle growth as needed. The extra speed is particularly noticeable in the search box at the bottom right of this weblog:

Screen Shot 2010 12 24 at 14.56.13

The second small change is that “Jee Labs” will be called “JeeLabs” from now on. It’s official. No more white space. Eight bits closer to world domination :)

I’ve been wanting to get away from the two separate words for some time now, one reason being that a single InterCapped name is more googleable – and this server migration seemed like a good time to make the switch.

So better get used to it, this is the name of the new-yet-unchanged home:


This was a fairly elaborate site migration for me, and now both and are done. I’ve got a few other changes ahead of me before the rented server (located in Nürnberg, Germany) can be taken offline. But that will have less impact and should be easy to finish in the months ahead.


Emergency stop

In News on Dec 22, 2010 at 00:01

This is a weblog post I never wanted to write…

If you’ve been waiting for stuff you’ve ordered from the JeeLabs shop in the past weeks, and it hasn’t arrived yet, then I have some really bad news for you: don’t expect anything the rest of this year…

I’m hitting the emergency stop button:

Emergency Stop

The two big issues in the past two weeks were mentioned in a recent post, and they are both of the kind I can (learn to) deal with: fluctuations in demand and fluctuations in supply, along with occasional shipping anomalies. It’s frustrating for everyone involved when this doesn’t work out well, but hey – been there done that, from both sides of the table now.

Trouble is, I’m now running afoul on a third hurdle: a couple of days ago, I strained my lower back. The trip to Braunschweig may have made it worse, unfortunately, although I had hoped these few days off would cure it. It’s most probably stress related, even though I consider myself an expert in stress avoidance. You see, normally I’m the guy who overcomes any type of setback, no matter what happens and no matter what the stress levels are. And having run a marathon 4 years ago, I have not the slightest inclination in the world to keep some mundane injury from letting me do what I love doing so much these days, i.e. taking JeeLabs further.

Except that now, I’m forced to pull all the stops on the shop. Continuing as is at this stage would be sheer folly.

There are currently some 70 back-orders. I will continue to send out packages as soon as new components come in. But given the delays of several of my orders, one of them pending for almost two months now, it’s no longer realistic to expect anything soon. The busiest delivery season of the year, a totally snowed-in infrastructure across all of Europe and beyond … it all doesn’t make the situation any better.

If you’ve been waiting for some time, please email me if you wish to cancel / get a refund and I’ll take care of it.

I’m not going to attempt to make a prediction for the next few weeks. My guess would be as good as yours. I can only wait, try and find out more about the actual status, and prepare to get things going again as quickly and smoothly as possible once everything returns back to normal.

Meanwhile, I’ve got some silly muscles to tend to… but that’s actually the easy and most predictable part!

- Jean-Claude

The downside of success

In News on Dec 17, 2010 at 00:01

With over 2,500 units produced to date, it’s safe to call the JeeNode (Kit + USB + JeeLink) a success. A runaway success in fact, in my opinion.

Great, but…

This isn’t purely good news, alas. The demand for JeeLabs products has been increasing so much lately, that I’ve run into serious supply problems in the shop these past few weeks. I can assure you that I’m extremely unhappy with that state of affairs – and the pain isn’t over yet, with some parts taking weeks longer than expected to reach me. This shortage might last into January 2011 for items such as the Ether Card.

So it’s a bit awkward to talk about “success” at a time when there are still 50 back-orders in the shop (down from 90…), with probably quite a few people frustrated by the slow delivery times. A postal strike next week in the Netherlands and the extra delays due to the busy Christmas season are clearly not going to help one bit.

Summary: the JeeNode design has been working out very nicely, but my ability to make it properly available is lagging far behind. My only way out is to “get larger quantities – sooner”. Which is exactly what I’ve been doing lately, in collaboration with Modern Device, who have started carrying more and more JeeLabs products for the US and nearby regions. We’re both scaling up, while trying not to drive ourselves off the cliff…


The current “crunch” is with headers, with 10,000 of them waiting in customs (again) and holding up just about everything, and with Ether Cards, RTC Plugs, and 2×16 LCD displays. That last one is holding up the Wireless Starter Packs as well.

In principle, all packages are sent out when complete, or nearly so in some cases. I cannot speed up things, although I keep looking for alternative suppliers. If you would prefer to get two partial shipments (no extra cost), please get in touch. I will of course also honor any cancellation, if you decide that you’ve had enough of this.

Please bear with me as I try to get over these growing pains. I apologize for all the delays and inconvenience this is causing. As new deliveries are coming in, I am continuously going through my backlog to fullfill as many pending requests as possible.

New server

In News on Dec 9, 2010 at 00:01

JeeLabs is leaving the dark ages behind… into the light!

Yesterday, the fiber-optic cable was finally delivered. It’s that long box in the middle with the wiggly split:

Dsc 2391

Roll-out by Glashart, modem installed bij NKM, support bij Lijbrandt. It took three months between bringing that orange fiber-optic cable into the house to getting hooked up to internet with it!

This is offered as a Triple play service, of which I’ll only be using the internet connection and a telephone line (yeah, voice-over-wire still exists!).

The internet connection is not too shabby – here’s the “low-end” version I ended up with:

Screen Shot 2010 12 07 at 10.59.21

To be honest, I couldn’t care less about the download speed. Been happy ever since ADSL passed the 4 Mbit/sec mark (the rest is marketing, same as the CPU GHz “game”, and the top speed of a car, if you ask me).

The key reason to do this was to increase the upload bandwidth, which was 1 Mbit/sec – until now.

So finally I can announce the new web server for the JeeLabs Café:

Say hello to…

Screen Shot 2010 12 08 at 16.03.12

I’ve been maintaining the docs in both places for a couple of months now. But as of today, will be deprecated. I’ll gradually adjust all the bits there to redirect to the new server. The old URLs will continue to work for at least another 6 months, but no guarantees after that.

So what’s the deal with the new Café site, eh?

Well, it’s powered by Redmine and has a lot more features than the old site, which is just some static pages:

  • A wiki – with all the info from the old site, organized in a similar way, but now more people can join and participate. There’s already a nice section of contributed pages – see the interesting projects page. The wiki supports Markdown format, and attachments (which can be used as inline images).

  • An issue tracker, to better keep track of bugs, feature requests, and source code changes.

  • A forums section, which may replace the current Talk forums. I haven’t decided, the feature set is quite different. Main issue holding me back for now, is the lack of a simple spam filtering mechanism.

  • A respository browser for all the source code maintained at JeeLabs. This is a very nice and powerful interface to subversion, with full access to change logs, older versions, and source code differences. This replaces the hack I had set up a while back.

Redmine has a number of other features which I haven’t enabled at this point. One of the things to note, is that it manages several different projects, including some private ones which aren’t even listed until you log in with the proper access rights.

Speaking of logins: all the info in the Café is public and browsable by anyone visitng the site. To submit bug reports or feature requests, however, you will need to register and log in. The process is simple an automated, with a quick check via email. To contribute on the wiki, I need to raise your access level to “Editor” – this is not automatic (to avoid spamming), so please contact me if you would like to add your own pages to the wiki or help maintain and extend pages already on there.

The main page of the new Café is at and here’s what it looks like:

Screen Shot 2010 12 08 at 17.34.20

There’s a separate Hardware sub-project in the Café with all the “official” documentation about hardware from JeeLabs. This is where you will find descriptions, detailed specs, connection diagrams, schematics, CAD files, and pointers to relevant posts on this daily weblog. An example:

Screen Shot 2010 12 08 at 16.29.51

Ok, enough screen shots. Back to work!

Meet the JeeNode v5

In AVR, Hardware, News on Sep 25, 2010 at 00:01

I’m very pleased to introduce the – Fresh!Updated!New!JeeNode version 5 board:

Dsc 1929

Hold on. Don’t get too excited. It’s not that big a deal. It’s basically still the same JeeNode v4, with just some incremental changes.

Allow me go through each of the differences in some detail:

  • on the left, there is now a diode between the FTDI power input and the rest of the PWR lines – so you can power the board from a 4.5..13V battery, etc. and it won’t fry the FTDI board or cable when plugged in
  • this also means that “PWR” will be about 0.7V lower on the PWR pins in several places across the board, than on the power supplied to the FTDI power pin (i.e. 4.3V when fed from a USB-BUB)
  • for 100% compatibility with the JeeNode v4 and older, the diode can be disabled (i.e. shorted out) with a solder jumper on the back side
  • two extra header pins have been added (+3V and RST), on either side of what was the “PWR/SER/I2C” header on the JeeNode v4 – it is now called the “PSIX” header (X = eXtended)
  • on the right, the RFM12B module was moved a bit to make room for a hole for the antenna wire
  • not as easy to see, but the board is also fractionally longer, so that the RFM12B no longer sticks out
  • slight re-arrangement of components (caps and reset pull-up)
  • most holes are slightly larger, making it easier to unsolder components, if you ever need to
  • the long sides of the board are now routed i.s.o. V-scored, i.e. much smoother and more precise:

Dsc 1966

That’s more or less it. Oh, and D O T Sfour big white dots on each side of the board to be precise, next to the PWR pin of each of the Port 1 .. 4 headers. You’ll be surprised by how convenient that can be when hooking up all sorts of plugs – which have the same dots to mark the proper orientation.

All in all, no big changes. Nothing incompatible with the JeeNode v4, the JeeNode USB, or the JeeNode SMD. This isn’t about planned obsolescence, these are just some tweaks to squeeze the maximum usability out of what is essentially the flagship and workhorse of Jee Labs, if you pardon this odd mix of metaphors.

I did forget to fix two little teeny tiny label name spelling errors which were also on the JeeNode v4 (left as exercise for the diligent reader). Oh well. I hereby claim victory anyway, and now declare this v5 PCB to be TUJ!

… TUJ ?

Yes: TUJ. Shorthand for The Ultimate JeeNode of course! What else?

PS. The JeeNode v5 is shipping now. I don’t play “There’s Something New Coming Soon” games.

Update – I’ve updated the documentation:

  • JeeNode v5 manual (PDF)
  • JeeNode v5 pinout (PDF)

It’s all a bit in transition, with the Café moving to Redmine soon – which is where these docs will go, eventually.

Back from vacation

In News on Aug 15, 2010 at 00:01

Last month, we (Liesbeth and I) spent a delightful time in the Provence:

Img 6808

As usual, that means I get to switch to my French persona, as we visit new places and meet delightful people of all ages. Lots of baguettes, cheese, wine, and fruit – as usual. Life is embarrassingly good this way…

We visited a friend of a friend at this amazing spot in the Provence:

Img 6691

I’ve never been in a house before, on top of a hill, with a 360° view towards all the surrounding mountains. Here’s the side of the house where we stayed:

Img 6659

It was an incredible place to be.

The geek in me couldn’t resist peeking at the way electricity is hooked up there:

Img 6741

The black box at the bottom right is an earth leakage circuit breaker, which trips at… 350 mA! IOW, it doesn’t protect people, only the house wiring! – luckily, a modern 10 mA version has also been added.

Lots of personal stories, which I won’t bore you with. Been back for over a week now, but still mostly in vacation mode. I’m looking forward to going into lots of Jee Labs projects again, starting tomorrow…

A few more images from the country which gave us the phrase Joie de vivre and a lifestyle I truly love:

Img 6739

Img 6780

Img 6732

Img 6391

P.S. Liesbeth took all the pictures, roughly 600 in all – I just tagged along to relax and enjoy…

June Special

In News on Jun 1, 2010 at 00:01

I’ve got two announcements to make:

1. Jee Labs will be closed from July 14th through August 14th

No new posts will be published on the weblog, and no orders in the shop will be processed or sent out during one month, starting on Wednesday “Bastille Day”.

2. Special discount during the entire month of June

Discount 2010

Today is a big day

In News on May 25, 2010 at 00:01

This is weblog post number …


Yes, five hundred!

If you’ve been following along, you know what I do, and why. And my views on OSH and OSS.

My motivation for the daily weblog format comes from a guy called Seth Godin, who – surprise! – writes a daily blog (for many years now). I find his never-ending stream of insights absolutely delightful and inspiring.

So what does it take to write about something I care about, day in, day out? Surprisingly little. The trick is to stop chasing quick results. And to stop chasing big results. The drive comes from within. The challenge comes from the problem. The goal is to understand and to solve. You start with a puzzle, you end up with learning something new. The journey is the reward, to quote Steve Jobs – something I profoundly agree with.

This weblog isn’t a race. To the top, more readers, fame, success, fortune, or even to get the most posts in. This weblog is a dedication, to those who explore and invent, and to those who teach and inspire. Day in, day out.

It’s a lifetime thing.

Check out the following story…

Driveby culture and the endless search for wowby Seth Godin, March 2010

The net has spawned two new ways to create and consume culture.

The first is the wide-open door for amateurs to create. This is blogging and online art, wikipedia and the maker movement. These guys get a lot of press, and deservedly so, because they’re changing everything.

The second, though, is distracting and ultimately a waste. We’re creating a culture of clickers, stumblers and jaded spectators who decide in the space of a moment whether to watch and participate (or not).

Imagine if people went to the theatre or the movies and stood up and walked out after the first six seconds. Imagine if people went to the senior prom and bailed on their date three seconds after the car pulled away from the curb.

The majority of people who sign up for a new online service rarely or never use it. The majority of YouTube videos are watched for just a few seconds. Chatroulette institutionalizes the glance and click mentality. I’m guessing that more than half the people who started reading this post never finished it.

This is all easy to measure. And it drives people with something to accomplish crazy, because they want visits to go up, clicks to go up, eyeballs to go up.

Should I write blog posts that increase my traffic or that help change the way (a few) people think?

Should a charity focus on instant donations by texting from a million people or is it better to seek dedicated attention and support from a few who understand the mission and are there for the long haul?

More and more often, we’re seeing products and services coming to market designed to appeal to the momentary attention of the clickers. The Huffington Post has downgraded itself, pushing thoughtful stories down the page in exchange for linkbait and sensational celebrity riffs. This strategy gets page views, but does it generate thought or change?

If you create (or market) should you be chasing the people who click and leave? Or is it like trying to turn a cheetah into a house pet? Is manipulating the high-voltage attention stream of millions of caffeinated web surfers a viable long-term strategy?

Mass marketing used to be able to have it both ways. Money bought you audience. Now, all that buys you a mass market is wow and speed. Wow keeps getting harder and dives for the lowest common denominator at the same time.

Time magazine started manipulating the cover and then the contents in order to boost newsstand sales. They may have found a short-term solution, but the magazine is doomed precisely because the people they are pandering to don’t really pay attention and aren’t attractive to advertisers.

My fear is that the endless search for wow further coarsens our culture at the same time it encourages marketers to get ever more shallow. That’s where the first trend comes in… the artists, idea merchants and marketers that are having the most success are ignoring those that would rubberneck and drive on, focusing instead on cadres of fans that matter. Fans that will give permission, fans that will return tomorrow, fans that will spread the word to others that can also take action.

Culture has been getting faster and shallower for hundreds of years, and I’m not the first crusty pundit to decry the demise of thoughtful inquiry and deep experiences. The interesting question here, though, is not how fast is too fast, but what works? What works to change mindsets, to spread important ideas and to create an audience for work that matters? What’s worth your effort and investment as a marketer or creator?

The difference this time is that driveby culture is both fast and free. When there’s no commitment of money or time in the interaction, can change or commerce really happen? Just because you can measure eyeballs and pageviews doesn’t mean you should.

In the race between ‘who’ and ‘how many’, who usually wins–if action is your goal. Find the right people, those that are willing to listen to what you have to say, and ignore the masses that are just going to race on, unchanged.

(Re-posted with permission)

Cat and mouse games

In News on May 2, 2010 at 00:01

Not so long ago, junk comments on the Jee Labs daily weblog started rising sharply:

Screen Shot 2010 04 28 at 11.14.10

Flagged by Akismet, but still a pain because I have to clean them up once in a while – and manually skim over each one to pick out any false positives. No fun, especially knowing that all this spamming is scripted – regardless how little effort it takes, life’s too short for this sort of nonsense!

Fortunately, there are additional tools for WordPress to prevent most of this junk from even reaching Akismet (which does a terrific job, btw).

As you can see at the end of the graph, the spam log is clean again. Five incoming junk comments in two weeks – that, I can deal with :)

Thanks to Project Honey Pot!

Digital postage stamps

In News on Apr 21, 2010 at 00:01

At last, this country has entered the 21st century…

Dsc 1347

It is now possible to print postage stamps with a label printer, instead of having to constantly buy stamps and place up to 8 (!) of them on the packages going out at Jee Labs. Not to mention keeping 4 different stamps around.

Until now, the only other option was to buy a fairly expensive franking machine which weighs the packages and prints stamps on them, but it doesn’t handle thicker packages, so I’d end up printing on separate labels anyway – and essentially waste most of the investment while still doing the same as before.

I’ll probably keep using stamps for the small shipments. But no more reams of stamps per envelope, new shipping options in reach, and no more running out of specific stamps!

Now, if only they supported the Mac… oh, well.

Welcome to the Café

In News on Mar 31, 2010 at 00:01

So far so good, I think yesterday’s community site setup is working out fairly well!

Here’s one of the pages, as seen by anonymous visitors:

Screen shot 2010-03-30 at 23.15.14.png

The same page, once you pick a username and register:

Screen shot 2010-03-30 at 23.16.02.png

As you can see, the site can be extended to include more features for registered users (there are lots more!).

TikiWiki has 12,723,940 options – I’ve only tweaked 83 of ‘em so far…

In fact, I’ve been turning off features, stripping menus, changing permissions, and simplifying the CSS theme, to try and regain some uncluttered screen space. I may have gone too far in some areas, but there’s definitely room for further simplification in others.

There are built-in anonymous, registered, editor, and admin “groups”, so we can make this thing as open as possible w.r.t. participation, while sharing the maintenance burden later on if this site becomes hyperactive.

I still find web-based page entry and editing extremely tedious. But I’m willing to stick to this wiki formatting convention, and I can easily use my own text editor to prepare new pages off-line when it gets too painful.

I’ve moved the site to its definitive URL ( and will also work).

The forum and the wiki/ wiki will be kept around in read-only mode for a month or so, until all the main content has been moved over.

Update 2010-04-02 – the Café has been closed again. I’m sticking to BBpress + ProjectForum for now.

One more Forum + Wiki try

In News on Mar 30, 2010 at 00:01

Ok, I’m going to try one more forum + wiki setup:

Screen shot 2010-03-29 at 21.45.15.png

Sample wiki page:

Screen shot 2010-03-29 at 21.22.43.png

It’s based on TikiWiki, as suggested yesterday.

This new setup is hosted on the Jee Labs server again. No user signup in some big wiki farm, no tracking of activity (I don’t do big-brother style “analytics” – not now and not ever…).

The interesting aspect of TikiWIki is that it is even more powerful than Wikidot, but that almost each individual feature can be turned off, so that I can pick exactly what’s needed to create a convenient site, without all the bells and whistles which would only distract from creating useful content and discussing important topics. The flip side is that it’s quite a large set of config options to navigate through!

I’ve replaced the Wikidot with this new site, again at – you are hereby invited to sign up and try it out (all user names are available, since this is a standalone setup). I can assure you that it is an order of magnitude more tedious for me as it probably is for you to have to go through all this hassle again…

As before – this is a test. Final decision as to whether this becomes the new Jee Labs community site will be made within the next 10 days … I sure hope this is it!

Less and less convinced

In News on Mar 29, 2010 at 00:01

After having played around a bit with the recently installed Forum + Wiki site, I’m having some serious doubts about switching over to it. Here’s the Sandbox page, as example:


Looks great, right? So what’s the problem?

It’s too powerful and it’s too complex.

The #1 feature which drew me to Wikidot, is its unification of a discussion forum with a wiki. The forum is very good: hardly any setup needed, good threaded discussions, good notification options, and good admin interface. Perfectly usable, right out of the box. As I described here, the combination of a timeline-oriented forum and a project / topic oriented wiki sounds like the pefect way to merge the two major areas one would like to have on a community-based site.

But the wiki, if you pardon my French, sucks

It’s an attempt to shoehorn formatting options, style elements, and content management features into a wiki-like syntax which just doesn’t make sense. Tables, tabbed views, modules, footnotes, formulas, … the list doesn’t end, but the confusion just increases as you go along. There are numerous ways to create links, yet I can’t make internal and external links appear differently on the page. The way to change a link’s title depends on the type of link used. Some features are modules, others are built-in. I don’t know about others, but as I’ve been trying out a few things, I’m not getting more and more used to the syntax – which to me is a sign that it lacks regularity.

In terms of site structuring features, there is too much functionality: sections w/ table-of-content, tags, categories, and parent-child page relationships. The problem with this is that every contributor will choose a different mechanism when adding new pages. Some people will put everything into a single page, others will try to create “islands of personal hierarchies”, twisting the available features to match a personal preference for specific pages. I don’t fancy spending my time editing pages and adjusting structures to try and unify things. And I’m only going to end up stepping on everyone’s toes if I change something they spent ages perfecting to look “just right”.

Don’t get me wrong. There is a lot to like about Wikidot.

But for an open community site, which aims to help lots of people find their way around, while letting active members share and contribute highly informative nuggets of knowledge (link broken as of 2010-04-05), I think the Wikidot format has (far!) too many degrees of freedom. Style should be pleasing (which is evidently a personal preference) but most of all it should be uniform. This daily weblog gets information across because its style was defined long ago and has become unimportant – both for me as writer, and for its readers, judging by the friendly emails I keep receiving.

A drawback which bothers me more than I expected: posting on the forums requires signing up with Wikidot.

The other thing I found out is that browser-based editing is tedious. There’s not much Wikidot can do about that (it does explain why I prefer email-based discussions over web forums).

If only someone would create the perfect community site … open source, preferably, with minimal lock-in!

I’m inclined to keep the current forum and wiki as is for now. They are not perfect, but Wikidot is too much of a compromise. Maybe something else will come along …

Update 2010-04-05 : this particular wiki is no longer being used.

New Forum + Wiki test

In News on Mar 27, 2010 at 00:01

The links at the top of this daily weblog are currently as follows:

Screen shot 2010-03-26 at 23.26.15.png

I’m not quite happy with that setup. The PROJECTS, DOCS, and CODE links point to stuff I’m working on and sharing through this site, but there’s a bit of a disconnect with what others are doing. It’d be nice to be able to maintain a list with other projects derived from (or perhaps just inspired by) the ones at Jee Labs. Likewise, the code I’m kicking into the world is only part of the story – what about changes and extensions by others? Or sample code? Wouldn’t it be nice to have everything available in a single place?

And then there’s the somewhat confusing separation between the TALK discussion forums and the WIKI pages. Both of them intended to help people share and exchange articles, code, images, etc.

Lastly, TALK is of course about asking questions, but wouldn’t it be nice to tie in much more to the pages to which these questions apply, and to have the answers easily reachable from those same pages?

I’d like to try something new. Better get it over with early on, and benefit as soon as possible from an improved community exchange site.

Meet the new experimental Forum + Wiki site:

Screen shot 2010-03-26 at 23.23.57.png

This is a unified forum + wiki setup. That concept in itself risks being so confusing that I’ve decided to start a Guidelines page to describe what I’m trying to do.

Will it work? I don’t know. Let’s review this a few weeks from now …

The trouble with a site change like this is that it’s going to be disruptive. Especially since I’m not yet 100% sold on adopting the above site and throwing out the current forum and wiki.

The current plan is to proceed as follows:

  • Allow everyone to explore and try out the new site, which is now public at
  • Keep the current forum and wiki links on this weblog intact for another week or two.
  • If the new test site is deemed effective, make it the default one.
  • Create read-only archived versions of the forum and wiki for reference.
  • Enjoy the new site, make it rock, and move on!

I hope this works out. Let me know what you think, especially if there is any show-stopper or other issue!

Merci, Paris

In News on Jan 5, 2010 at 00:01

Just got back from a couple of very relaxing days in Paris.

Here’s a quick impression of the 1680′s Comédie-Française (on the right):




We went there to see a nice French theater piece. And although I’m not even remotely as culturally enlightened as such a remark might suggest, I did have a great time.

Normal transmissions to resume tomorrow…

Happy New Year!

In News on Jan 1, 2010 at 00:01

Here’s my little thank you for everyone who has supported Jee Labs in 2009 – in one way or another …


No need to hurry, January has 31 days. I’m away now, will reply and send out discount codes on Monday.

Goodbye 2009

In News on Dec 31, 2009 at 00:01

This year has been a very exciting year for me. Hardware, software, hacking, coding… I’ve been having an absolutely fantastic time – and I hope you enjoyed reading about some of these adventures.

Before the year ends, I want to apologize for the mess highlight the delightful variety of pages this has led to.

Below are quick snapshots of the headers of different areas reached through this main navigation bar:

Screen shot 2009-12-22 at 22.55.36.png

First, there is the daily weblog, with over 350 posts in WordPress and new posts added with MarsEdit:

Screen shot 2009-12-22 at 22.30.38.png

Next the documentation area, which looks the same, but is managed by an app called VoodooPad:

Screen shot 2009-12-22 at 22.43.17.png

The open source code is maintained in a subversion repository, and can be browsed online using ViewVC:

Screen shot 2009-12-22 at 22.31.38.png

The discussion forums are managed by WordPress’ little bulletin-board cousin, bbPress:

Screen shot 2009-12-22 at 22.42.06.png

The project-oriented wiki is handled by a product I’ve had some involvement in, called ProjectForum:

Screen shot 2009-12-22 at 22.32.37.png

And lastly, the Jee Labs web shop is hosted at Shopify (a bit weak on int’l features and progress, alas):

Screen shot 2009-12-22 at 22.32.53.png

Six areas, and almost as many very different presentation styles! Most stuff runs on remote servers, the rest is a copy of what’s on my machine. A substantial portion relies on open source, but some bits use strictly commercial software.

I wish I had the time (and the skills) to turn all of these into a single consistent presentation, but I don’t…

To me, the current state of Jee Labs is a pretty good illustration of where we stand with computing at the end of this first decade of the 21st century: amazing things are possible with incredibly modest means, but it’s essentially one huge mish-mash of completely different trends, strung together with this duct-tape we’ve called the web.

Anyway – so much for technology.

See you in 2010! May it bring you lots of friendship, wisdom, and creativity to make this world a better place.

Update 2010-04-05 : this particular wiki setup is no longer being used.

Biodegradable bags

In News on Dec 15, 2009 at 00:01

I recently ran out of the silvery electrostatic bags I’ve been using to package JeeNode kits and other stuff. So for the next batch, I decided to use bags which are biodegradable. They have a funny soft feeling to them and are actually much more flexible:


These bags come with a “Farnell” ad printed on them (the supplier of these bags) – so be it…

If you order stuff from the Jee Labs shop, you may also receive stuff packaged in small clear plastic zip-lock bags. That’s because I have them lying around anyway – they are re-used from the extension cables, which I received in packages of 1-per-bag, whereas they are sent out as 5-per-bag. Since the harm of having “consumed” these plastic bags has already been done, might as well re-use them a second time…

FWIW, I feel pretty bad about adding so much packaging to a world full of junk already. And being involved in quite a bit of transportation of all this stuff, both by getting it here and by getting it out as packages to lots of people. Atoms ain’t bits – that’s for sure!

All I can say is that I save up and batch my orders as much as possible, and use as little and as light packaging as I think I can get away with.

Meet the new JeeLink v2

In Hardware, News on Nov 3, 2009 at 00:01

Just in!


Look at that fancy gold lettering – neat, huh?

And the first hand-soldered unit is working perfectly:


Here’s the new software-controlled LED:


This is in addition to the red TX and green RX LEDs, indicating USB activity.

Only thing not tested yet is the new on-board 1 Mbyte flash memory. Once that’s done, I’ll start assembling a couple of these. Will be a lot easier once the solder paste stencils come in.

Shop news

In News on Oct 27, 2009 at 00:01

Big news today for people from the US, Canada, Australia, and other parts of the world where the 915 MHz band is available for use with JeeNodes.

Paul Badger of Modern Device has added JeeNodes and a few other items to his shop – check it out:


Please be patient as Paul gets all the necessary bits and pieces ready, but this means you’ll be able to get Jee stuff with US prices and (much) lower shipping costs if you live on the other side of the big pond.

Behind the scenes, Paul Badger has been actively involved in the Jee Labs since early this year. I’m very happy that at last he’ll also be able to get involved with actual shipments.

Things are still evolving quite rapidly here w.r.t. plugs, so we’re still figuring how and when to make all the different plugs available, boards, pre-assembled, etc. The intention is to eventually provide all the same options as in the European Jee Labs Shop, but it may take some time to get there. It’s going to be a bit tricky to get it right with such a moving target…

This change also means that I’m no longer offering 915 MHz units from Europe – just 868 MHz.

On the plugs front there is some good news as well, as final versions of the Blink / Expander / Memory / RTC / UART plugs and the Proto Board are set to arrive here tomorrow. I’ll be updating the various bits and pieces and pictures once they come in, of course.

The astute reader will notice that there are still a few items missing. I’m expecting a few more boards by the end of the week, but there are also some delays due to a production issue which requires some boards to be re-made. That means some boards won’t be in for another two weeks and there’s little I can do about it :(

Not to mention the fact that stupid little mistakes with boards seem to have become a habit of mine… each mistake leads to a new round trip to the pcb shop, i.e. 3 weeks on average. Which is why I’m juggling as many overlapping release cycles as I can – while trying not to make yet more mistakes!

Next month all this frantic shop stuff should be over, and I hope to get back to some “real” lab work, with more s/w coding and finishing up some of the numerous projects cluttering up my desk… eh, I mean my entire office!

Happy birthday, Jee!

In News on Oct 25, 2009 at 00:01

Today, exactly one year ago, I discovered the Arduino platform and decided to explore it and write about my adventures. That’s when this weblog started. Within a month, it became a daily weblog – as it still is today.

Early 2009, the JeeNode was born. Like every youngster, it has kept me very busy ever since, deep into the night at times. Fortunately youngsters grow up, eventually …

So today, I’d like to announce the availability of the JeeNode v4 – the fourth iteration of the JeeNode:


The one thing you’ll notice (other than the by now “standard” blue-and-gold design) is the changed PWR/I2C header, left of the ATmega chip. It now includes the RX and TX pins, and has moved to a new location, closer to the port headers. The 4 inner pins are still the same. And it’s now called the PWR/SER/I2C (PSI) header.

The back of the JeeNode v4 has changed a lot more:


Text! Lots of clearly readable labels to indicate what all the ports and pins are. And on the far right three “check-boxes” to mark which type of radio is on the board. The white area in the middle is for writing down your own info, such as the node ID assigned to this unit – or which sketch it is running. See the updated documentation.

The JeeNode v4 replaces the JeeNode v3 as of today. Le roi est mort, vive le roi!

As you may have seen, the new JeeLink v2 USB stick was announced a few days ago.

Along with these two, I’d also like to announce that a new JeeNode USB v2 prototype is currently on its way. It has exactly the same size and layout as the JeeNode v4, but with the FTDI pins replaced by a mini-USB socket (same as what’s used in most digital cameras). The JeeNode USB v2 replaces the JeeLink v1, using a different USB connector. Like the JeeLink, it is built with SMT components:

Picture 2.png

The JeeNode USB and the JeeLink are USB devices, and have three LEDs: green/red for RX/TX activity on the USB port, respectively, and a blue LED which could be used as wireless activity indicator. The base JeeNode has no LEDs, but it’s very easy to add an activity LED between SPI/ISP header pins 2 and 8.

The two JeeNodes will of course continue to work just fine with all the plugs, but they are also a particularly nice match for the new Proto Board:


(shown here half-inserted on a JeeNode v4 for clarity)

I’d like to point out that the Proto Plug gives access to 18 of the ATmega328′s 20 I/O pins. Only two pins are dedicated to the on-board wireless radio module (INT0 and SS). To put it differently: these JeeNodes add ports as a modular way to extend and use the ATmega I/O capabilities, but their use is entirely optional: you can simply ignore all the extra supply and ground pins if you don’t need them. And you can run totally unmodified Arduino sketches on the JeeNodes and JeeLink.

So there you have it. One year old, yet already grown up: a nice little range of modules which combine low-cost wireless with an Arduino-compatible design, using a modular architecture for tying stuff to the physical world…

I’m very proud to see how far Jee Labs has come in one year, and can’t wait to put these building blocks to new uses and to see what others figure out to do with all this.

No longer under the radar

In News on Sep 5, 2009 at 00:01

Looks like the days of innocence are over for this weblog:

Picture 1.png

Not to worry (it’s all filtered out automatically), but I still have to scan that stuff once in a while to make sure there are no false positives.

Oh well, I s’pose it comes with the territory…

September – grand opening

In News on Sep 1, 2009 at 00:01

It’s September 2009, ten months after I started on my “Computing stuff tied to the physical world” adventure. Arduino, RepRap, modding, trying to fit stuff together, software in a chip – my, my, I never thought it’d be that much fun!

Here’s a part that came out of an old CD-ROM drive:


What does (did) it do? Is it human? Hmmm.

Whatever it is, this thing pretty much sums up all the geek stuff I’ve stumbled upon in these past months. Weird. Designed. Fun. Mass produced. Functional. Useless on its own. And still mostly a male thing ;)

But this isn’t just about what happened so far. The fun really is the excitement of entering a new future, best described by the motto “If you can’t open it, you don’t own it” – see the Maker’s Bill of Rights.

I’ve only started to scratch the surface of all this. It’s fascinating how many people are latching on in the same way – across all ages and all continents. With websites such as instructables springing up to collect and share the huge variety of “DIY” projects and hacks. Boundless creativity, for and by everyone.

Today is also the day I’d like to declare the Jee Labs Shop officially “open”. There are only a few “items for sale” to use marketing-speak. My main reason for doing this is that I want to create real stuff – and a shop with products is in a sense as real as it gets. You can buy things there if you want to get going quickly with stuff I’ve been working on, or you can make it all yourself using the information on my weblog. Everything is 100% open source, meaning that all the documentation is available for you to use / adapt / refine / extend in any way you like.

I owe my inspiration to the countless people who share and discuss their work and ideas openly on the web. The daily Jee Labs weblog is my attempt to give something back in return. It’s a drop in the ocean, but hey it appears to be appreciated :)

And I owe much my motivation to your comments on the weblog + forum and in particular to those of you who have bought stuff from the new shop. You know who you are, and you’ve made my day each and every time. Thank you for your vote of confidence!

As a token of my appreciation, everyone who has posted on the weblog or forum and everyone who has ordered from Jee Labs in the past can get a 20% discount on new orders. I don’t want to send around unsolicited emails to everyone, so please send an email to jcw <at> to get a discount code which can be used in the web shop until September 30th.

Ok. Back to designing, soldering, hacking, coding, sharing, and posting. Enjoy!

Back in August

In News on Jul 16, 2009 at 00:01

This is to announce that I’m suspending this weblog for a month to take some time off. No new posts in the coming weeks, but you are of course welcome to browse around in everything that’s been posted so far.

This is my 217th post, i.e. over 7 months of daily posting about all sorts of embedded and wireless fun stuff since this weblog was started. A lot of different topics have been covered, from getting the wireless radio to work, via a couple of excursions into robotics, to the latest reflow developments here. I hope you’ve enjoyed all this as much as I’ve enjoyed diving in and writing about it all. I’m sure there’s a lot more fun waiting down the road, and am looking forward to get back to this after the summer.

Here’s my very latest progress on the new JeeLink. I don’t have all the parts yet, so this isn’t a complete unit, but you can see where it’s all going:


As you can see, there are a couple of solder bridges, i.e. too much paste. But the “big” chips both do appear to have lined up quite nicely and the simple parts are all fine. All I need to do is get the solder paste amounts down next time. Man, this stuff sure is tiny.

Enjoy, and watch out for those soldering fumes! ;)

Documentation area

In News on Jul 10, 2009 at 00:01

There have been some changes to this weblog since it was moved to another server a few days ago. The navigation links at the top of each page now work better, for one.

Another change is that I’ve started setting up some more documentation pages, and am integrating them into this website. Here’s what you get when you click on the “DOCS” link now:

Picture 1.png

I would have loved to get some really nifty sidebar navigation in there, but for now there are simply two mechanisms to help you out: first of all there are quite a few links between pages – this is automatic, and hence very convenient for me: wherever text appears which matches a page in the documentation, that text will be linked. The other navigation feature is the “page index” link at the bottom of each page. It’s not very sophisticated, but hopefully workable for now.

Keep in mind that searching in the weblog will not find anything in the documentation pages – these are internally two completely different systems.

Needless to say perhaps, but these documentation pages are still at an early stage. They will be filled-in, extended, and updated for some time to come.

Vacation time

In News on Jul 2, 2009 at 00:01

For your information: I’ll be off-line from July 15th through August 15th. It’s that time of year for me to let go and re-charge again, far away from gadgets, internets, and computer screens. Because everything has its place, including the real world.

The intention is to have the new JeeNode v3 kits and boards available before then, but it really depends on whether the latest design works properly. I hope to find out in roughly a week.

The shop will stay on-line, but please be aware that if you order anything there will be no packages sent out during that period. Right now, the shop is still in basic start-up mode. No more, no less. With a bit of luck, I can still send out some new kits before my leave.

Ok, back to some fun stuff. Here’s a mystery JeeNode


See if you can guess what the different pieces are and what all this is for. Two hints: the chip on the right is transparent (it hasn’t been hooked up yet), and there’s a solar cell still waiting to be connected to the top and bottom leftmost two JeePlug pins.

The mystery will be solved in tomorrow’s post.

New Jee Labs forums

In News on Jun 27, 2009 at 00:01

Right on the heels of yesterday’s shop announcement, I’ve now also set up a site for discussion about everything related to the Jee Labs:

Again, a very basic design with with only a limited set of features in the form of a new bulletin board called bbPress – from the makers of WordPress:

Picture 3.png

If this turns out to be a convenient and effective setting for discussions, I will remove the jeelabs mailing list at Google Groups again. With apologies to everyone who already signed up there.

To summarize, there are now three different sites for the Jee Labs, using the new domain names:

So much for the world domination side of things – now I can put on my lab coat again and get on with it.

New Jee Labs shop

In News on Jun 26, 2009 at 00:01

I’ve set up a web shop to simplify getting JeeNode kits – and whatever else comes out of Jee Labs - to those of you who are interested. The shop has its own web site:

It’s a basic design, because this is not about trying to become the next Amazon. Or acting like it. Or trying to “project a corporate image”. I’ll leave that to others.

Nah, the JLS is just a an easy-to-use shopping cart setup for dealing with PayPal and bank transfers:

Picture 3.png

No muss, no fuss. I hope you like it.

Note that there’s a Product News page in the shop, which is a blog I’ll use to announce the “availability of new products”. I won’t clutter this daily weblog with that sort of sales/marketing drivel. To track both types of news, simply subscribe to both blogs.

New name and new domain name

In News on Jun 23, 2009 at 00:01

I’ve decided to switch to a real top-level internet domain name for this weblog, and am moving this entire site over to its new location:

Did you notice the extra “s”? Did ya? Did ya?

Actually, the weblog home is at to be pedantically precise – but you can pick whichever URL you prefer, since you’ll automatically be redirected to the right place. Both names have been permanently tied together – inasmuch as permanent means anything on internet, that is.

The “” URL (no “s”, see?) will continue to work as a redirect to the new location, at least for a while so everyone can gradually adjust all bookmarks.

This change will be instant because it’s entirely virtual. This is merely a naming issue.

I’ve also adjusted the name of this blog. The “Jee Labs” plural form feels right for various reasons. Several people were in fact referring to this weblog in that way already.

More JeeNode v3 changes

In Hardware, News on Jun 22, 2009 at 00:01

Here are a few more details about the upcoming JeeNode v3 board.

First off, I said no more changes w.r.t. the pinout. Not true – the I2C/PWR pinout has also changed:


For a couple of reasons which I don’t want to go into just yet. The GND pin is now on the outside, just as on the FTDI header. Note that PWR is the incoming voltage, not the regulated 3.3V at which the ATmega operates (including those SDA / SCL pins).

The other change worth mentioning here, is that components have been rearranged slightly to make room for 2 pads to connect a battery or battery pack – along with holes for strain relief. Both leads are clearly marked “+” and “-” to avoid polarity mistakes.

The JeeNode is well suited for battery use due to it’s 3.3V design and because it has no on-board LEDs. The regulator lets you choose from a huge range of battery options (hence the soldering pads i.s.o. a fixed battery choice): 3x or 4x AAA or AA, NiMH or Alkaline, or one of the increasingly popular 3.6 .. 4.1 V Lithium batteries, which are great as long as you take care not to short-circuit them and not to discharge them beyond their advised limits.

So there you have it. The new JeeNode v3 board is just about ready to send off to manufacturing. I hope to get my hands on them early July.

JeeNode v3 pinout

In Hardware, News on Jun 20, 2009 at 00:01

There are two important pinout changes in the upcoming JeeNode v3:

  • On all four ports, pins 4 and 5 will be swapped (AIO and +3V)
  • Pins 1 and 2 of the SPI/ISP header will become pins 7 and 8

So the final pinout for ports is:

Preview of “jeenode-v3.graffle”.png

The change isn’t being made on a whim – I’ve got several things plugging into ports here which will need to be changed to work with the new pinout. And it will affect everything plugged in for years to come. One of the reasons for the change is that it lets you plug in a 3-wire servo (pins 3..5). Another reason is that it is compatible with the BBB board already out there (also pins 3..5).

As before, a 4-pin connector on pins 2..5 is often all you need. The outer two pins are for more advanced uses.

As before also, pin 1 carries the input voltage to power the board, and can be anything from 3.5V to 13V. With an FTDI connector it will usually +5V. Batteries work great, anything from a 9V block, or 3x AAA/AA (both NiMH and alkaline), or even a LiPo battery.

Note also a small change in pin names: the 3.3V regulated power supply is now called “+3V” instead of the somewhat ambiguous “VCC”, and the interrupt line is called “IRQ” instead (was INT).

Every future JeeNode design will use this pinout on every port.

The new SPI/ISP header is (pin 1 at top left):


This is an “extended” ISP header. The main reason for this change is that pins 1..6 are now compatible with a standard 6-pin in-system programming connector, through which the ATmega’s fuses, flash, and EEPROM can be programmed. Note that the JeeNode is a 3.3V device, it should not be driven by an ISP programmer set to 5V voltage level.

The two extra pins are tied to digital I/O lines B0 and B1, and allow connecting more SPI devices to the JeeNode. Note that SPI is used internally by the RFM12B radio module, so these pins should not be re-configured for other purposes, although you could use SEL0 and SEL1 as general-purpose I/O lines if you want – a LED and a push-button switch perhaps.

I’ve made a few experimental add-ons using the SPI/ISP connector, such as this one. They will need to be adjusted for v3, but as with ports the same new pinout will be used for all future JeeNodes and derivatives from now on. Although some of them might not have such a connector at all.

That’s it – no more changes. Now I can “standardize” everything I want to connect to the JeeNode ports!


In News on May 5, 2009 at 00:01

Had a wonderful time in Barecelona, admiring Gaudi’s fantastic architecture such as the roof of “La Pedrera”:


You might not have noticed my absence since the daily Jee Labs weblog updates went on as usual, based on posts which were prepared in advance.

Anyway, it’s good to be back …


In News on Apr 15, 2009 at 00:01

Today is my birthday. Regular broadcasts resuming tomorrow.


That’s me, a couple of decades back, around the time when the PDP-8 came out. No chips, no personal computers, no Internet, no Google, no mobile technology.

All prerequisites for the JeeNode :)

JeeMon demo (alpha)

In News, Software on Apr 9, 2009 at 00:01

Today I’m releasing a first version of the open source JeeMon home monitoring application, along with a demo dataset. Warning: this is an early alpha version – all features and bugs are still likely to change, a lot!

There are builds for Windows (x86), Mac OS X (x86 and ppc), and Linux (x86 + x86_64 + some embedded systems, such as the JeeHub’s MMnet1001 module).

It takes 3 steps to run this demo – there is no installation:

  • Get a runtime for your computer from this area
  • On Unix-like systems, run this: chmod +x JeeMon-*
  • Launch JeeMon

Here is the debug output this generates on my laptop:

Picture 1.png

And here’s a Windows screenshot with similar output:

Picture 1.png

Now point your browser to http://localhost:8888/ to see what JeeMon has to offer.

When started for the first time, JeeMon downloads a few extra files from the internet: “Jee-demodata”, “Jee-library”, and “Jee-library.update” (under 2 Mb total). These files are obtained from public servers at Dropbox, I do not track downloads or statistics.

On every subsequent startup, JeeMon looks for updates and refreshes the “Jee-library” file if there is a new version, so by simply starting JeeMon again a few days later you can track its development progress. To disable automatic updates, delete the “Jee-library.update” file.

I’m releasing this code to give you an early glimpse into the Jee Labs kitchen – and to gauge the interest and figure out how to improve JeeMon. If the demo works for you, great. If it doesn’t, you can either try to figure out what the problem is, or delete all the Jee-* files and try again at a later date. The new mailing list announced yesterday is open to anyone wishing to comment and make suggestions.

Let me reiterate that this JeeMon alpha release is for infinitely curious and technically interested people, not for those looking for a finished home energy monitoring solution. Running this JeeMon demo is bound to raise more questions than I can deal with – but it’s all open source, so feel free to explore this as much as you like.

Whatever. Enjoy …

Update – the demo dataset now contains data since 2009-01-01, i.e. a total of over 3 months of readings.

New "jeelab" mailing list

In News on Apr 8, 2009 at 00:01

For those who want to share their interest / questions / ideas w.r.t. any of the Jee Labs projects, I’ve set up a mailing list at Google Groups:

Picture 2.png

See – if you don’t want to sign in to Google to join this list, let me know and I’ll add your email address manually.

Update – the mailing list has been replaced by the Jee Labs discussion forums at

One hundred!

In News on Mar 21, 2009 at 00:01

This blog has reached its one hundredth post – whee!

If you follow this weblog regularly, you may have noticed that there is now one post per day, day-in-day-out and always at 0:01 CET. This is not because my working days and hours are so regular – far from it – or necessarily always late, but because this self-imposed daily schedule helps me stay focused.

It’s all supported by a bit of automation in WordPress – I simply try to keep a handful of posts scheduled “in the pipeline”, so that these writings aren’t driven by some sort of daily deadline panic. On some days I have nothing to say – and I don’t – while on others I’m pleased to find that I can touch on a couple of topics, some of which are hopefully of interest to you, dear reader.

Speaking of whom… it’s always nice to hear from you. I’d love to read about what interests you in this “Computing Stuff Tied to the Physical World” as the title of this weblog says, as well as your suggestions on how to further improve this weblog.

So much for the intermezzo on this first day of spring (for the northern hemisphere that is). Tomorrow’s post will resume with a photo, graphic, or sketch – as always.

Enjoy your reading!

PS. FYI, I recently added a bit more background info about me on the About page.

It's called a JeeNode

In AVR, News on Feb 13, 2009 at 00:07

In case you missed that last image of my new Arduino’ish / wireless’ish design, here it is again:

It’s called a JeeNode

It’s simple, it works, and I hope it’ll become useful as building block for all sorts of tasks around the house. The previous post has all the details.

And now it has a name: I’m calling this a JeeNode.

I’ve also added a Projects page to this blog (near the top), to more easily find related posts.

Blog redirect

In News on Feb 6, 2009 at 00:05

I’ve “moved” this blog to – but it’s all smoke and mirrors really: underneath, it still redirects to the site which continues to host these pages just as before.

Update – I’ve also changed the blog title to match the domain name. Less confusion. See the about page for further details.


In News on Jan 7, 2009 at 17:03

This weblog was moved from RapidWeaver (which doesn’t scale, sigh) to a hosted one using WordPress. Right now, I’m now using MarsEdit to manage this blog.

All older entries have been moved over, but not all links and source code listings have properly made it across the transition. The original blog is still archived here.