I think I have the ESC nailed. I have a procedure for powering up that seems to give predictable robocar behavior.

Do you all have some creative ideas for things to do with this little car. Right now it follows a wall counter clockwise looking down at a leisurely pace. High speed introduces response time problems. Two sonar proximity sensors can be placed looking anywhere from the car and a pot controls the top forward speed the half forward speed.

I can show you all the code if you like. It is crude, but it works.

Ken