We start with [usedbytes] and Zero Entertainment System [usedbytes] has crammed an entire emulator into a classic Nintendo Entertainment System control pad thanks to the Raspberry Pi Zero.Zero Entertainment System also has something the original NES couldn’t dream of having: An HDMI output. We’re happy to say that [usedbytes] knew that hacking up a real Nintendo controller would be sacrilegious, so they grabbed a low-cost USB clone from the far East.[Radomir’s] custom tote board interfaces the servos to the Pi Zero itself.The Pi Zero opens all sorts of doors for sensors, vision, and advanced processing.
The filter in this case is a 7-pole Chebyshev low-pass filter.
The filter keeps the Pi’s harmonic filled square waves from messing up every band from DC to light.