This is a small software sound synthesizer for the stm32f4discovery board. Makefiles, init code and such are based on a simple mp3 player that seems to be based on ST's samples contained in the STM32CubeF4 package, and some parts are copy-pasted around the net and the Cube samples.

This was quickly written in about two days for the ELL-i bare metal hackathon in May 2014. Some explanations in Finnish in my blog. Feel free to fork and experiment for fun. Do quote the original sources when publishing your changes.

Set up potentiometers as voltage dividers to PA1 and PA2. Communication works with the USART on pins PD5:PD6. Sound outputs from the audio jack.