m8ec

Embedded Client for the Dirtywave M8 Headless. Power-efficient and cost-efficient desktop-free head.

Goal

Complement the Dirtywave M8 headless (Teensy 4.1) with a display, keypad, and an audio interface that are similar to the original M8 hardware unit. The peripherals may be driven by a microcontroller acting as a client (USB host) to the Teensy 4.1 running M8 headless firmware. Have fun and learn something along the way.

Requirements

• Complementary hardware peripherals must be easily available and cheap.

Plan (draft)

graph LR
    D[Keypad] --> B
    A[Dirtywave M8 Headless] -----|USB| B[STM32 MCU]
    B --> C[Display]
    B --> E[Audio Out]
    F[Audio In] --> B
    subgraph m8esc
        B
        C
        D
        E
        F
    end

• Start with the hardware you have on hand:

  • Microcontroller: WeAct STM32F411CEU6 Black Pill.
  • Display: 2.8" TFT LCD (ILI9341) module.Keypad: Modified USB mechanical key number pad as GPIO input. Probably...
  • Audio out interface: PCM5102A module.Audio in the interface: PCM1802 module.

• Hook up the display to the Black Pill.

• Find a good library for the display. DMA-driven SPI - must, FreeRTOS compatible - must. Candidates:

  • https://github.com/ardnew/ILI9341-STM32-HAL: DMA, FreeRTOS. Probably try this one first as it looks easiest to get going on the Black Pill (STM32 HAL) and test the display.
  • https://github.com/martnak/STM32-ILI9341: no DMA, no OS support, but may be useful for reference.
  • https://github.com/juj/fbcp-ili9341: made for Raspberry Pi, but may be useful.
  • https://github.com/adafruit/Adafruit_ILI9341: looks mature, but Arduino - may require some work to port.
  • https://github.com/PaulStoffregen/ILI9341_t3: Teensy 3.x, but may be useful for reference.

• Get the display working with the Black Pill. Draw some stuff on it.

• Figure out the USB client interface. Research what M8 Headless expects from the client.

  • https://github.com/laamaa/m8c could be very useful although it's for Windows/Linux/MacOS.

• Get the USB client working with the Black Pill.

• Get the display working with the M8 headless via USB client.

• Modify the keypad to be driven by the Black Pill GPIO.

• Get The Keypad working with the Black Pill.

• Get the keypad working with the M8 headless via USB client.

• Hook up the audio-out interface to the Black Pill.

• Get the audio out working with the Black Pill.

• Get the audio out working with the M8 headless via USB client.

• Hook up the audio in the interface to the Black Pill.

• Get the audio in working with the Black Pill.

• Try to get the audio working with the M8 headless via a USB client. From reading online, it's tricky.

Looking Into Future

• MIDI in/out? If supported by the M8 headless.
• Eurorack System Integration? Maybe make a module out of it.

Links

• Original Dirtywave M8: https://dirtywave.com/products/m8-tracker
• M8 Headless: https://github.com/Dirtywave/M8HeadlessFirmware