Computing stuff tied to the physical world

Meet the JeeLink

In AVR, Hardware on Jun 24, 2009 at 00:01

I’m proud to announce a new board next to the JeeNode, called the JeeLink. Yes, there’s a pattern in the naming choices made for products on this site.

The JeeLink is very much like a JeeNode, but in the format of a USB stick and with a few small differences listed below. Here’s the layout:

Picture 2.png

As you can see, the JeeLink has basically the same headers as the JeeNode, but with a USB plug in the place of the JeeNode’s FTDI connector.

The JeeLink is useful in two different ways, I think: first of all, if you have a couple of remote JeeNodes, you’ll probably need a central node as well to tie the whole network to a personal computer. The second use case is that it can be used as a JeeNode with built-in FTDI-to-USB conversion – which is exactly what it is, technically speaking.

A major difference with the JeeNode also, is that the JeeLink is built with SMD parts. The intention is to make it available in pre-assembled form and as bare board. No kits with parts – that’s reserved for the JeeNode since I don’t want to stretch myself too thin.

There will be a more detailed description of the JeeLink once it is ready and working, but here’s a first overview:

  • the dimensions of a JeeLink are slightly different, obviously
  • the I2C and SPI/ISP headers are not in exactly the same position as on the JeeNode
  • there’s no battery connector (who needs one with USB?)
  • the FTDI-type USB connection includes two on-board activity leds

So there you have it – a new descendant in the Jee family. With on-board RFM12B wireless radio of course, and 4 ports to connect absolutely anything you like to. Just like the JeeNode.

The JeeLink is the initiative of – and was designed in collaboration with – Paul Badger of Modern Device. We’ve been having a heck of a time together, hammering out all the details and making sure the result will be as good as we can possible make such a new concept. I’m proud of the result, and hope you’ll like it as well. Should have properly working JeeLinks in my hands in July, assuming Mr. Murphy doesn’t barge in to spoil the party.

  1. Nice :)

    You might already know about V-USB (aka. AVR USB), but I post it anyway just in case: http://obdev.at/products/vusb/index.html

    This is a software implementation of the USB protocol, enabling USB connectivity to a normal AVR with a minimum of external components, making it possible to reduce costs of USB boards such as yours since the FTDI chips tend to be pretty expensive.

    I’ve been playing around with this a bit lately and I like it.

  2. These are great news! I am definitely interested in one, to serve as the listener to the jeeNodes I just got from you! Count me in for one!

  3. Hi! For the range and reliability in difficult conditions (concrete walls inside the house etc.), does you node design allow mesh networking?

  4. Any news on this? Can we expect JeeLink to be available in the shop before your vacation?

  5. Yes, I hope so – I am waiting for a shipment with boards and parts from the US, should be in any day now. Then some assembly and testing to make sure things work as intended. Sorry to keep you waiting – there were some delays involved in getting al this here…

  6. Thanks, yes – I looked into it. Any of the ports could be used for this (D4..D7) when combined with the IRQ line (D3). This is not perfect, since D3 is INT1, not INT0 – i.e. not the highest priority interrupt on the system. Maybe D3 is workable, if not this would entail a design change, swapping the INT0 and INT1 pin allocations.

    Another option would be use a separate ATtiny45 to replace the FTDI chip, but I’m not sure it’s worth the trouble. The way I look at it, the normal use case would be to have one or two JL’s (for development and for easy testing with both sides of a RF link plugged in), and the use lower-cost JN’s for remote nodes.

    And then there’s the FTDI cable / USB-BUB approach, which I use with JN’s all the time: one USB hookup, saving duplicate hardware.

  7. Great – glad you like it. I’ll of course announce once the JeeLinks are working 100% and ready. It’s easy to make mistakes with these things. And SMD is still very new to me.

  8. Here’s in the house I’m getting sufficient range to cross through 2 stone walls and 1 reinforced concrete floor without any problem @ 57600 baud. Total distance around 10 .. 15 meters. Reception across two reinforced concrete floors failed though, last time I tried. Range could be increased a bit by using lower baudrates and narrowing the bandwidths, but I haven’t tried that.

    I haven’t looked into mesh networking, but Stephen Eaton has started working on that for his Wireless Widget boards – see http://code.google.com/p/strobit/wiki/WidgetMesh for some information.

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