bydogen

I’ve been (hardly) using my EEE with a VGA->composite adapter and a bluetooth keyboard as wearable platform (see this picture on flickr), but am bothered by the setup time it requires. Ideal would be a wearable that’s light, compact, fast enough for what I want (linux + Xorg + terminals + extra + some multimedia), have a battery with sufficient battery life (preferably +5 hours) , built in charger (preferably running on USB), hookups for enough stuff and generally be and look geeky.

As my recent linkdump shows, i’ve been looking into cortex boards as a platform and am lured in by the featureset, overall speed, power usage and of course price.

So based on that platform I’ve been clicking around some sites and talking to my main man in EE, xSmurf. Together with his remarks I’ve come to the following list:

1. Main platform:
   • Get a ARM Cortex board (probably the devkit8000 one, as it has svideo output already)

     This would get to run a simple linux install (probably gentoo as neuvoo) with Xorg and some freaky tweaked WM for low-res usage (my HMD is <320×240 and black&white)

   ~150 euros

2. Subsidiary platform:
   • A simple Arduino clone run from the TTL uart on devkit8000 (but maybe use an atmega with >1 uarts?)

     Probably I’d like this for some stupid hacks while walking around
     Also, this could be very good for the switchable power interface for some of the devices (HMD, Wlan, Powered HUB) aswell as monitoring the Power platform (voltage, temperature, charging state)

   • (If I can figure out the overlay support on my HMD) A TellyMate

     This could output all the system information, powerlevels etc

   ~10-20 euros

3. Power platform:
   • MAX1811 chip for charging Li+ single cells from USB

     No idea how this would work when charging multiple cells, maybe I need more than one

   • (as they are hella cheap) Trustfire 18650 3.7V 2500mAh cells or maybe the protected variant

     This would get me ~2hr per cell on just the main platform,  so I’ll start with 2 and will try to get it to work with more than 1 before adding more cells
     Besides USB charging, I think I’d like the cells to be removable, so I can charge them outside the device. (while wearing it, for instance)

   ~ 10-15 euros

4. Interfaces:
   • HMD for output

     This will be my current HMD for starters, a really cheap toy part that was recommended by hackaday.com
     Shown would be the current application in fullscreen mode, as anything else on this resolution is just insane (although Q3 looked nice )

     ~20 euros (but I already have it)

   • Audio

     Probably wired, as the devkit8000 has connections for this, but could move to A2DP (through a USB BT stick)
     Would be used for playing notfications and general sound from applications, but could also be an A2DP and/or Headset relay to a mobile phone for mid-firefox calls.

     ~10 euros (but I already have it)

   • Wireless

     Will use some USB wlan stick, maybe two
     General connecivity of course, the second one would just be for wardriving

     ~20 euros (but I already have it)

   • USB

     Will need a powered hub, so thats another ~2A for the batteries, sigh
     This will be quite usefull for random USB harddrives , usbsticks , and I guess a cardreader

     ~10-15 euros

   • HID

     Probably my current bluetooth keyboard, together with a PS2 mouse (that funky logitech netbrowse thing I have stored away)~80-100 euros (but I already have it)

5. Case:
   • Hahahahaha

Total costs : 180-200 for my situation, 310-360 for ground up building

I’ll have to put this on hold until I find another pot of gold some day, but these prices are really quite decent imho.
Also, I will be experimenting with small parts of this, maybe I’ll collect all the parts reaaaaally sloooooow.