Wearable computing project SBC's

**approxSeth** · 04-30-2006, 10:35 AM

I am doing research for building a wearable computer system. I have a lot of my personal preference spec's nailed down, and I've narrowed down my SBC format to mini-ITX, which brings me to you fine gentlemen. I hope that in the following weeks you can help recommend a suitable board for use in my system.

But what I am asking today is a different matter, and may not be exactly your expertise, but you might (I hope) be able to point me in the right direction. I understand that this forum is for embedded audio systems in cars, but believe it or not, while searching for LCD, wearable computing, SBC's and Mini-ITX this forum has come up dozens of times in the past month and a half.

With that disclaimer in mind, here's my question:

I have a rather novel idea for a hand-free keyer for input for my WearComp. It involves flex sensors like those used in VR data gloves and the Nintendo "Powerglove" of yore. I'm not planning on playing with the complexities of analog sensors beyond a configurable threshold.

IE: Flex sensors run along the back of my hand and over the first knuckle on the five fingers of my left hand. When bend beyond a certain threshold flex sensors will be registered on the analog I/O sensors of a SBC running Linux. The combination of these five binary digits 00001 through 11111 allow for 31 'keys'. This is sufficient for the 26 letters of the alphabet and enough 'shift/command' keys to simulate a 101-key keyboard.

These calibrated flex sensors will be connected to a wrist mounted SBC. At this point I am considering a Gumstix with some kind of analog i/o ports (Robostix?) to integrate with the flex sensors.

The SBC will then in turn decipher the finger positioning, convert it to standard keyboard code and transmit it through bluetooth (or hardwire when power's needed) and run as a keyboard for the WearComp.

Am I completely off my rocker with this idea? Is it too complex or am I some how heading in the completely the wrong direction? Is the SBC I'm describing far too complicated or not powerful enough for the task? How would you go about this project?

If this isn't exactly right for this forum, or none of you have the knowledge or simply don't want to nurse me through the project, do any of you know where a better forum to start might be?

**Scouse Monkey** · 04-30-2006, 10:40 AM

look for a smaller PC. either an industrial SBC - eg kontron or avantech, or maybe the new nano-itx.

The Kontron 768 is a good little PC and has a 1ghz p3 drawing about 22W so it not bad on power. that is about the same size of a 3.5" hdd but you can do smaller if you dont mine losing power and go for a lighter OS. You can evn get PCs as small as credit cards or some of the PCs that fit in wall sockets (they are honstly that small) can play mp3s and do networking as they are deisgned to be used in home automation and entertainment.

**approxSeth** · 04-30-2006, 10:46 AM

Originally Posted by Scouse Monkey

The Kontron 768 is a good little PC and has a 1ghz p3 drawing about 22W so it not bad on power. that is about the same size of a 3.5" hdd but you can do smaller if you dont mine losing power and go for a lighter OS.

That's exactly the type of info I was looking for. Those spec's are probably a lot higher than I need for the wrist SBC part of the project, the Gumstix is a 200mhz or 400mhz 3.3v system, about the size of a finger. Which is well under the size requirements I am expecting for a wrist mount. The problems is I don't know *which* SBC I would use if not the Gumstix, and I don't exactly know where to start.

The system you were describing to me sounds perfect for the backpack mounted WearComp proper. I'll look into that now, thank you.