A testbed for trying out sound synthesis ideas built from off-the-shelf modules.

The current hardware. Hotglued to an A4 aluminium panel (with plastic standoffs).

Click image for YouTube video.

Right now my main focus is still on Chatterbox, but prompted by that I wanted to have a setup with more power and flexibility (Chatterbox has just an ESP32 with external DAC).

Probably the first bits I'll be playing with will be around delay lines and granular synthesis.

PS. very soon after uploading the above, decided to add an Arduino Mega 2560.

The software for this module I'm putting in a separate Github repo : sound-machine-mega2560.

• Arduino Due : main audio processing
• Arduino Mega 2560 : user interface (keypad, display(s), rotary encoders)
• ESP32 : I/O (Wifi/Web, MIDI, Bluetooth)
• External stereo ADC (I2S)
• External stereo DAC (I2S)
• 4x4 Keypad (matrix)
• 20x4 LCD (I2C)
• Rotary Encoders
• External PSU

I may well add a little TFT graphic display

I'm using PlatformIO on VSCode (on Ubuntu). This seems much more convenient for larger projects than the Arduino IDE.

More frequent updates will appear in notes.md

2020-10-16

So far I've just hooked up the keypad and display to check they work (yes!). Libs:

• https://github.com/Chris--A/Keypad
• https://gitlab.com/tandembyte/LCD_I2C
  • see also : https://randomnerdtutorials.com/esp32-esp8266-i2c-lcd-arduino-ide/

It may seem perverse using 3 fairly low-capability modules rather than, say, putting everything on a Raspberry Pi. The coding there would almost certainly be easier. But I reckon I can still keep the total cost down, I already have these modules (!) and also any finished machine doesn't necessarily have to use all the modules. It's also modular! The blocks, eg. Mega + UI components, could be used alongside a completely different system. What's more this should be more fun!