Old good projects are always good to have near by. Projects in Cornell University are being stacked from 1999 and there are many wonderful ideas and finished microcontroller designs. Some of them we are going to review here from time to time.
This Lego vehicle has been modified so it could be controlled by AT90S8535. Despite code and AVR microcontroller are obsolete, it can be modified to newer very easily. Microcontroller can accept 6 commands from 6 buttons for controlling steer left, right, move forward, reverse, stop, rise and lower tray. Two stepper motors provide steering while DC motor is used for forward and reverse movement.
Car even has a differential wheel system run by planetary gear system. Motors are controlled via transistor switches that accept 5V from AVR microcontroller board and provide 12V switched voltage. Really cool project for hobbyists.