Bring the productive bustle of ambient coffee shop sounds with you anywhere by building a white noise machine in a cup! This project uses the Adafruit Audio FX Board to play a 30 minute audio file on repeat. The circuit is battery powered with the help of a lipoly backpack, which also allows for convenient recharging over USB and the easy addition of a power switch. A speaker rests inside the lip of the cup, driven by a class D audio amplifier using a 10K potentiometer for volume control.
The Cup o’ Sound requires no programming and is excellent for practicing your through-hole and free-wire soldering skills. The result is a satisfyingly compact handful of portable sound that can be reused in many contexts or rewired to act as a speaker alone.