First robot is getting a rename. Partially due to the realization that you can’t really explore with out mapping capability. No biggie, but this will take a little time. My thought is to go with having the Arduino send vector data to the Raspberry Pi. I found some useful info to help me build maps on a blog by a Martin Thom.
I also found a great video on building an autonomous robots that has helped me clarify a few things, and lots of great info at Society of Robots.
One thing that has become abundantly clear is the need for encoders on the drive wheels. Critical for both navigating and map making. This spurred me to work on building an encounter for my toy wheels.
Using a new Gorilla Glue product and much trial and error, I was able to glue four magnets to each of two cogs from the gear boxes. Result is messy looking but does function well.
Added a Hall Effect device on the outside of the gearbox.
Newbury Pi 