I am looking for a wrist-wearable development platform solution with the following specs:
- Some kind of a display that you can see in the dark as well as in bright sunlight.
- Hardware buttons (as opposed to touch-screen).
- User-programmable on the CPU level (ideally in C).
- CPU does not have to be awfully fast, 100MHz would be plenty
- Somewhat documented interface with working examples
- It would be nice if the board could run Linux
- It would be nice if it also had a GPS chip
- Something that can be mass-produced at some point to turn into a commercial product.
The best I've been able to find on the market is so far Motorola's MotoACTV which becomes an OK development platform once you root it, but it has a few problems:
- Definitely not low-power. With display on, and WiFi/GPS/Ant+ sensors off, it lasts maybe only 8 hours. With GPS on only 3.
- To interface with display and buttons you pretty much have to go through Android as bypassing it creates some serious hurdles - mostly due to the lack of documentation/examples.
- ANT+ interface is a beast to get working as you have to reverse engineer a lot due to the lack of documentation. I have made some progress there, but have not yet been able to actually obtain the signal.
- With GPS you are stuck with the Motorola driver which has some serious issues - sometimes it takes 30 minutes to get the signal, then the signal is often not very accurate. I have made an effort to bypass it and write my own, made some progress, but this is another uphill reverse-engineering battle again to due the lack of documentation/examples.
- Even if I get everything to work perfectly, this is not a viable commercial development platform.
Ti has Chronos EZ-430 which is sort of in the area, but it is lacking some capabilities. It might be possible to instrument it with WiFi/Ant+, but if so, I lack the hardware expertise.
Any ideas on how to build my "dream" gadget would be appreciated - either pre-made product, or a list of parts/instructions how to put them together including the box/wrist-band to make it wrist-wearable.