Heteromycin - 3D printer board

Heteromycin is a 3D printer controller that aims to provide a full stack user experience around Octoprint / Marlin using a custom designed board that integrates a Raspberry Pi 3 or Zero W. It will also provide a solid, powerfull hardware by utilizing quality components, a STM32 32bit MCU and powerfull TMC5160 or TMC2160 driver (SD / SPI mode).

Features

• 32bit STM32H743VI 400Mhz / 1024KiB RAM / 2MiB Flash MCU / 4 KiB EEPROM
• Integrated Raspberry Pi 3 / Zero W HAT connector as the main user interface
• Integrated DC/DC switching module for 5V / 3.3V power supply
• 5x TMC5160 or TMC2160 stepper driver with 8x external Power MOSFET each
• 3x high power MOSFET for heating (2x heater, 1x heatbed, 24V)
• 4x low power MOSFET for fans (5V or 24V)
• 40 pin external connector for STM32 and Pi GPIO pins
  • GPIO
  • PWM
  • UART
  • SPI
  • I2C
  • 3.3V / 5V / GND for external power consumption
• Micro SD Card for storing GCODE files (directa MCU access)
• Designed for a 24V power supply
• Automotive fuses
• Quality connectors
• Octoprint plugin for flashing the firmware of the board (STM32)

Roadmap

• Hardware
  • [x] Describe the general functionality and select the main components
  • [x] Draw the schematics of the PCB
  • [x] Placement & routing of the PCB
  • [ ] Production of a development board
  • [ ] Testing the PCB
  • [ ] Repreat until hardware is finished
• Software
  • [x] Write arduino core board definition once first PCB design is finished
  • [ ] Write PIN file for Marlin
  • [ ] Test board (esp. the TMC*160 driver)
  • [ ] Octoprint plugin for firmware upgrade
  • [ ] STM32flash rewrite (fix I2C and add SPI, maybe rewrite in rust)
  • [ ] Create a script / image with Octoprint with the plugin / tools preinstalled
  • [ ] Documentation

Alternative Parts

Stepper driver

You can use both TMC5160 or TMC2160 as the stepper driver, since they both are functionally / pin equal when used in SD / SPI-Mode.

It doesn't mater choosing one over the other, other than price and availability.

Fine tuning of the MOSFET driver may be necessary.

License

The hardware is licensed under CERN OHL version 1.2. The software is licensed under GNU GPL v3.

The files under PCB/packages3d are excluded from this license and are provided under fair use terms for this open-source project.