Computing stuff tied to the physical world

Posts Tagged ‘JeeRev’

Goodbye JeeMon

In Software, Musings on Jun 6, 2012 at 00:01

As long-time readers will know, I’ve been working on and off on a project called JeeMon, which bills itself as:

JeeMon is a portable runtime for Physical Computing and Home Automation.

This also includes a couple of related projects, called JeeRev and JeeBus.

JeeMon packs a lot of functionality: first of all a programming language (Tcl) with built-in networking, event framework, internationalization, unlimited precision arithmetic, thread support, regular expressions, state triggers, introspection, coroutines, and more. But also a full GUI (Tk) and database (Metakit). It’s cross-platform, and it requires no installation, due to the fact that it’s based on a mechanism called Starkits.

Screen Shot 2012 05 23 at 19 26 10

I’ve built several version of this thing over the years, also for small ARM Linux boards, and due to its size, this thing really can go where most other scripting languages simply don’t fit – well under 1 Mb if you leave out Tk.

One of (many) things which never escaped into the wild, a complete Mac application which runs out of the box:


JeeMon was designed to be the substrate of a fairly generic event-based / networked “switchboard”. Middleware that sits between, well… everything really. With the platform-independent JeeRev being the collection of code to make the platform-dependent JeeMon core fly.

Many man-years have gone into this project, which included a group of students working together to create a first iteration of what is now called JeeBus 2010.

And now, I’m pulling the plug – development of JeeMon, JeeRev, and JeeBus has ended.

There are two reasons, both related to the Tcl programming language on which these projects were based:

  • Tcl is not keeping up with what’s happening in the software world
  • the general perception of what Tcl is about simply doesn’t match reality

The first issue is shared with a language such as Lisp, e.g. SBCL: brilliant concepts, implemented incredibly well, but so far ahead of the curve at the time that somehow, somewhere along the line, its curators stopped looking out the window to see the sweeping changes taking place out there. Things started off really well, at the cutting edge of what software was about – and then the center of the universe moved. To mobile and embedded systems, for one.

The second issue is that to this day, many people with programming experience have essentially no clue what Tcl is about. Some say it has no datatypes, has no standard OO system, is inefficient, is hard to read, and is not being used anymore. All of it is refutable, but it’s clearly a lost battle when the debate is about lack of drawbacks instead of advantages and trade-offs. The mix of functional programming with side-effects, automatic copy-on-write data sharing, cycle-free reference counting, implicit dual internal data representations, integrated event handling and async I/O, threads without race conditions, the Lisp’ish code-is-data equivalence… it all works together to hide a huge amount of detail from the programmer, yet I doubt that many people have ever heard about any of this. See also Paul Graham’s essay, in particular about what he calls the “Blub paradox”.

I don’t want to elaborate much further on all this, because it would frustrate me even more than it already does after my agonizing decision to move away from JeeMon. And I’d probably just step on other people’s toes anyway.

Because of all this, JeeMon never did get much traction, let alone evolve much via contributions from others.

Note that this isn’t about popularity but about momentum and relevance. And JeeMon now has neither.

If I had the time, I’d again try to design a new programming environment from scratch and have yet another go at databases. I’d really love to spend another decade on that – these topics are fascinating, and so far from “done”. Rattling the cage, combining existing ideas and adding new ones into the mix is such an addictive game to play.

But I don’t. You can’t build a Physical Computing house if you keep redesigning the hammer (or the nails!).

So, adieu JeeMon – you’ve been a fantastic learning experience (which I get to keep). I’ll fondly remember you.


In Hardware, Software on May 10, 2011 at 00:01

Sorry, no serious weblog post this time. I’ve been distracted by an iPad which got delivered here today.

Couldn’t resist trying out some stuff…


Here’s one in landscape mode:


(both screen shots were created via the simulator, but the real thing looks exactly the same)

It’s obviously just a web browser. It’s also totally obvious to me now that touch screens are a natural fit for this sort of stuff. Goodbye double-click, hello swipe and pinch.

Pretty amazing how long we’ve done without ’em!

Web hooks and feeds

In Software on May 8, 2011 at 00:01

I’m starting to look into hooking stuff together via TCP/IP on the PC/Mac host side of things.

One approach is to use Web Hooks. The idea is that the sender initiates a simple HTTP GET or POST request to some web browser, with all the information contained in the URL and/or query arguments.

In JeeRev, I decided to try it out by adding a webfeed feature and a webhook feature.

The webfeed mechanism is absolutely trivial: make a web request to a URL with the name of the parameter and the value of the parameter at the end, and add any other info you want as query args:

This creates a new reading for parameter “abc-def” with value “123.45” (I used the scaling mechanism in this example, but direct input of “123.45” would have worked too).

That means any process with access to the webserver running in JeeRev can feed values into the system.

The reverse is the webhook: each time one of a specific set of parameters changes, a web request is made to a configurable URL, with the parameter name, its value, and such filled in automatically.

Here’s an example feed to the ThingSpeak web service:

Screen Shot 2011 05 07 at 17.03.54

(hmmm, looks like ThingSpeak only presents information on an hourly basis)

There’s no coding involved with either of these features in JeeRev, it’s all defined in a local config file.

Trivial. There really are tons of ways to do this collecting / storing / graphing stuff, and you can find lots of sites doing similar things all over the web these days. The Pachube website has been around for some time and appears to be used a lot.

To be honest, I would think twice before handing over my home monitoring and automation info to a public website. Sure, it might look cool to show everyone what you’re doing at home, and what you’ve automated – but it’s a privacy risk I can do without. I don’t intend to create a public site for JeeLabs sensor access and control. That’s the whole point of JeeRev: low cost hardware, running a local monitoring and control system, with optional outside access via secure channels, i.e. a password-protected SSL connection. The technology is open, but not our data (not even energy info: I’m more interested in optimizing than in making a statement).

The way I see these web hook/feed mechanisms, is not to create a world wide web of things, but as a way to tie different software systems together within the confinements and privacy of the home. Every device, app, and language has web technologies built-in these days, so it’s only natural to use them as exchange mechanism.

But I’ll leave the “look ma, my front door is open” sensor reports to others ;)

Update – the ThingSpeak web site service does support private channels and more fine-grained access, see the comments below.

JeeRev pre-release

In Software on May 5, 2011 at 00:01

As mentioned in an earlier post, I’ve been working on a new open source software design lately:


Best way to introduce it is perhaps to just copy this blurb from its home page:

Physical Computing projects usually involve several components: the hardware, the firmware for it, and code running on a PC, Mac, or Linux box. I’m tired of having to manually plug in / unplug devices all the time, start compiles, upload code, launch apps, and go through the same edit-build-launch-debug-quit cycle over and over again. It’s all so brittle, repetitive, and at the same time so hard to automate to the point where you can leave a non-trivial setup running unattended once it works. There has to be a better way. JeeRev is about growing and evolving such systems more organically.

You could call it “JeeMon, Reloaded” – but that’s not 100% accurate, because JeeRev is built on top of the existing JeeMon core. And in the grand scheme of things it’s in fact only half of the way w.r.t. where I’d like to go: JeeRev is an application framework to help build a new “environmental monitoring and home automation” system.

JeeRev 0.9 is a pre-release in the sense that I’m still just tipping my toes in the water of all this physical-computing-with-monitoring-and-automation stuff. But the path forward is getting clearer all the time, and many of the choices so far are starting to settle and work out nicely.

JeeRev aims to be as light as a butterfly, as flexible as a bamboo twig, as distributed as the wind, and a open as source code can be. You are welcome to participate in this project – in any form, at any time: at last count, there were some 2,718,281 fascinating avenues still waiting to be explored ;)

I don’t intend to flood this weblog with posts about JeeRev, but as with the hardware side of things I do hope to report advances once in a while, when they lead to practical uses for Physical Computing.

Because magic is fun, and magic is what happens when you bring together the worlds of atoms and bits!