Documentation of building a polyphonic MIDI synth & generative sequencer using the STM32F401 & STM32F746 discovery boards. If you want to build your own synth, sign up for a workshop @ http://workshop.thi.ng 

stm32f4/f7

Experimental spiral oscillator (x 2, slightly detuned) + fixed LPF @ 11.8kHz. Oscillator takes y-value of 2d spiral equation to produce waveform (with PolyBLEP to smooth). No filter modulation. LFO is only used to modulate number of spiral turns/twists (0.5 - 3.5)

sin(lfo * phase) * phase / TWO_PI

stm32f7 - synth - spiral

Another bunch of variations (using different LFO settings) of the test bass step sequencer. More info: https://hackaday.io/project/9374-stm32f4f7-synstack

synstack - forth - bass seq variations

Some dirty easter beats made w/ Ableton + fat bassline and other synths brought in (sampled) from STM32F7, courtesy of http://thi.ng/synstack

20160325 sketch (STM32F746 + Ableton)

Best enjoyed with headphones! Recorded live set in hotel after last minute tech issues during my lecture. Turned out the Korg nanoKontrol lost its configuration earlier - such a shame, was looking forward to hear it on big speakers! :)

Synth is running on a £35 STM32F746-DISCO board and also implements a 2-track 8-step sequencer w/ interactive controls for osc waveform, filter, env, delay, LFO and global transpose all via Korg nanoKontrol... Activated notes are randomly picked from a fixed scale (only once, not random at every invocation)

STM32F7 live recording (Resonate)

http://thi.ng/synstack demo running on ARM Cortex-M7 / STM32F746-DISCO, full source code http://github.com/thi-ng/ws-ldn-12 (ex07)

stm32f7 - synstack - 3 osc + fb + sdramdelay (WS-LDN-12)

Another workshop example (ex06), more info here: http://thi.ng/ws-ldn-12

synstack - forth - bass seq variations

forthcharlie