I have a new plan to control the much faster 1/10 scale toy car which is fast, but does not contain proportional controls. The trick is to turn the wheels only for a short period of time (150 msec at the moment) then 'kick' (supplement the springs) them back to neutral.

If the neutral is well calibrated (the 1/10 cars have a knob that centers the wheels) this method makes the car turn with little swerve. I need this while wall following. Otherwise the car crashes into the wall before the code/DPDT relay/steering wheels can react.

I'll make a video if this really works.

Ken