I have a mad urge to build an interactive amusement for the left-at-home dogs in my extended family. Yeah, I know other people have-done/are-doing this. So what. Details at http://dicks-raspberry-pi.blogspot.com/, post 99.
Anyway, one feature has to be the ability of the device to spit out doggie treats. I expect the main computer for this will be a Raspberry Pi. And I started stepper programming in Python on the Pi but realized quickly that precise timing is a problem again. Mostly because I want to be able to calibrate the motor position using a photo sensor. Reading such a sensor on the non-analog Pi is slow. So I'll add an Arduino for the motor and the photo sensor chore.