DIY MIDI Sound Synth using additive synthesis technique runs on a 32-bit MCU.
NB: This is a preliminary version with minimal functionality for development on the experimaental proto board (pictured). A future revision will support a user-interface (1.3 inch OLED display, buttons, 'data entry' pot) and voltage control of oscillator pitch, modulation, etc, using ADC inputs instead of MIDI... (jumper-selectable option).
For details of concept, design and operation, please refer to the project web page, here...
https://www.mjbauer.biz/Sigma6_M0_synth_weblog.htm
This repo contains an Arduino "sketch" (program) which runs on a synth module based on the Adafruit "ItsyBitsy M0 Express" (ATSAMD21) MCU board. The same firmware should run on compatible MCU boards, e.g. the Chinese 'RobotDyn' SAMD21 M0-Mini.
The synth application was developed originally on a PIC32MX platform using Microchip MPLAB.X IDE.
Since it is now difficult to obtain a breakout module or proto board based on the PIC32MX family,
I have migrated the application to a better supported, readily available 32-bit MCU device,
i.e. ATSAMD21, as in Arduino Zero, Adafruit SAMD21 "Itsy-Bitsy M0 Express" boards and compatibles.
Although I'm not a big fan of Arduino IDE - it doesn't support modular software design - I am aware it has become the development environment of choice for the majority of hobbyists. Further, I must admit that Arduino facilitates quick and easy firmware development.
For anyone still interested in running the Sigma-6 app on a PIC32MX platform, details of a suitable hardware design can be found on my website: www.mjbauer.biz. The program code is available on request.