A FM synthesizer based on the famous Yamaha DX7. For Teensy 4.0 and ESP8266 Orignally from: https://bitbucket.org/folle/arduino-fm-synthesizer/

Sound are synthesized from a sine wave 32 algorithms (same as the ones in the Yamaha DX7) 6 operators 6 envelopes generators (one per operator) Rate Scaling Level Scaling MIDI velocity (8 curves) MIDI input (supports pitch bend and a sustain pedal) 48000 Hz sampling rate 6 note polyphony Internal and external DAC support (by using the i2s bus) Real-time response to hardware controls (to change operators settings and volume)