Key upgrades for the old robot, I think would include:
- Proper four wheel drive
- Closed loop motor feedback
- Ultrasonic ranging on the sides as well as the front
- Light sensors in place of the camera for line following
To make the sensors work, I need more interrupt pins than the two that I have available on the AtMega 328 I used last time. I really need two for each wheel speed sensor, plus one for each ultrasonic sensor. I'd use a Cortex M4 like the Stellaris Launchpad, but the wheel speed sensors of course output 5V, as are most ultrasonic sensors and the inputs on the L298 H-Bridges I use.
I feel a custom circuit board coming. Oh dear oh dear.