My geeky idea is a Dalek with object recognition and different behaviors based on what it sees. I have recently acquired two 12'' rc daleks, one functioning and one for spares, and the motor section is actually well built. I will use a RPI3 for the image recognition and an Arduino for the movement and obstacle avoidance, so as not to encumber the RPI too much. Trying to find a viable way to turn an optical mouse into an odometer for motion tracking. Any tips VERY welcome.