I made a few Microbit Robots for the local library coding class.

This one was printed from scratch.

These two used commercial chassis.

They all use a homemade dual motor driver I had posted on Instructables years ago. I originally designed it for CNC use but it works better in a bot.

The first controllers used the accelerometer for steering. Later I turned this old yard sale find N64 controller into a microbit host.

The board is a perfect fit

 

MicroBit Brained Robots