Turntable Turns Waveform Generator
In need of a waveform generator for another project, [David Cook] crammed out the old turntable to modify it for a handy hack: By adding a simple reflectance sensor to the pickup he turned it into a waveform generator that optically plays back arbitrary waveforms from printed paper discs.
For his hack, [Dave] created a 3D printed mount, which attaches a LED and a photodiode to the pickup of the turntable. The mount also blocks most of the ambient light, allowing only the reflected light from the paper disc to reach the sensor through a small slit. A little breadboard …read more