For Pi #2 I'm looking at building a cycle computer.
I already have a hub dynamo with cache battery and USB output, so I have a power source for the Pi which will be constant whilst I am out and about (I expect power draw to be significantly under 3W without significant graphics output).
[SON hub dynamo with a biologic ReeCharge]
I'll be wanting a pair of USB cameras (to allow me to review my decision making as well as to provide evidence in the event on an incident), a USB stick for recording onto (and being able to pull and give to the police) and a USB GPS device for further logging, as well as providing a time signal on boot.
Finally a couple of buttons/leds attached to GPIO will signal:
- Stop recording and unmount media (light to show completion)
- Stop recording and shutdown (light to show completion - particularly important when I stop, I don't want corrupt data.)
Any new USB media would be auto mounted for recording (Can't decide between going FAT or EXT2).
GPS logs may be recorded to both SD and USB (because I like GPS logs, and don't want to sacrifice them to PC plod)
Obviously the above could all be accomplished with an RPi model A (and a 4 port USB hub) - although I'll probably do the dev work on a model B
If I get hold of a decent motor then I will look at gertboard additions to provide power control - again this could easily be logged, and the GPS data could be used to refuse power above 15mph (to comply with UK law)
I need to look for half decent USB cameras (preferably IP rated) but I can happily buy one at a time