I want a featureful and easy to expand bike computer for my electric bicycle and I have a high performance computer with a great display that I carry around with me all the time so I am developing an Android accessory bike computer, the DroidCycle. I already have an “off the shelf” motor controller handling all of the high power electronics and I have developed my own LED driver module for driving the headlights and taillights from main battery power. For the Android interface and handling all the realtime sensor monitoring and control, I have selected the mbed LPC1768 because it has an available library for the ADK and the online compiler means that 1) I don’t have to waste any time setting up the toolchain myself and 2) I can work on my firmware in wherever I am in whatever tiny scraps of time I have.
After several rounds of sketches and system analysis I have finally arrived at this schematic for the motherboard.
Since the mbed and the LED driver modules contain all the high frequency components, I can safely build the rest on perfboard saving me time and money. Next is ordering the parts and finishing the firmware.