Electronic drum synthesizer
Fully operational drum synthesizer based on a 32bit microcontrollers.
The project is natural continuation of the previous midi controller -> Drumidy
In the project I utilize nearly full potential of 32bit microcontrollers to generate realtime audio signal based on a signal from 18 external inputs.
The synth uses previously loaded into external ram audio samples to generate polyphonic audio signal with up to 25 simultanious voices.
Compare to the previous version, the system became much more complex with many processes operating in parralel. This project was started during The Big Component Shortage so 90% of components on the board are salvaged from a single Nucleo64 Board by STMicroelectronics.
On the board the full functionality is devided between 2 microcontrollers.
MCU2 – responsible for the graphic interface (TFT display 240×320), user input (2 encoders and 11 buttons), and USB midi communication to a possible host.
MCU1 – operates as an audio processor and performs 4 parralel tasks:
– Analysing 18 inputs and performs peak search (generating external events)
– Recoding external stereo audio signal with dedicated 24bit ADC
– Composing audio signal using data from external RAM with up to 25 simultanios voices
– Feeding composed data to external Audio DAC
Additionaly, for each external event MCU1 generate a MIDI message and sends is over to mcu1’s USB.
By default the audio samples are played from RAM because of the communication speed, but for the testing, it is also possible to play samples directly from USB memory or an SD card (reducing polyphony to 7-8 voices at a time).
HONORABLE MENTION
The same electronics was used in another project by a student of mine who adopted it to create a real-time DSP for his guitar (multi-effect stompbox). Later this work became his bachelor thesis which he successfully defended in the spring of 2023.
https://github.com/giacomo-ascari/digital-pedal
Both systems are still work-in-progress and hopefully soon will be substituted by the brand new itteration of Drumidy 3. Stay tuned!