Adrià Navarro created this excellent DIY DJ turntable from a junk pile walkman and PC fan. When you rotate the fan with your fingers, the voltage is read by an Arduino, which smooths and remaps the levels and then uses PWM to control the audio casette player’s motor. For good measure, Adrià added an array of LEDs to show the speed of playback. Inspired by him, I’ll be fishing through my junk pile to see if I can give new life to any dusty old parts.
Scratching Analog Audio With a PC Fan