DC motor controller board
Way back in 2006 I built this nice dc-motor controller board with the l298n chip.
Here are some pictures:
Nowadays in 2021 you can get a very similar and dirt-cheap controller board on aliexpress L298N driver board module . Still it was satisfying to be able to make this from scratch using just a chip and some protoboard. Also my version already had a pic micro controller added that would interface the buttons, debounce them and drive the pwm signals to the l298 chip (which is just an h-bridge chip) to send current to the motors.