Minnow is an Arduino-based Pacemaker client implementation for 3D printer, CNC and laser cutter controller boards.

The Pacemaker protocol is defined here: https://github.com/JustAnother1/Pacemaker

The Minnow firmware was originally created by Robert Fairlie-Cuninghame based largely on the Marlin printer firmware by Erik van der Zalm.

The firmware is intended for both standalone Arduino-based controller boards (using a PC or similar host platform) as well integrated Arduino + ARM controller boards.

The Minnow firmware and Pacemaker protocol have been specifically designed to support a sustained, high rate of individual movement control segments with minimal processing overhead on the client, thereby allowing the use of a cheaper controller whilst also yielding a far more sophisticated level of motion planning, co-ordinate remapping and better support for non-linear co-ordinate systems than most current solutions without requiring a real time operating system on the host.

The firmware has also been designed to provide a flexible host-based configuration system so that individual firmware builds are not required for different printer and controller configurations.

The Minnow firmware also supports an arbitrary number of devices - steppers, digital input & outputs, heaters, fans, buzzers, etc (limited only by the device's capabilities).

System requirements:

• a 16Mhz or 20Mhz AVR Arduino (i.e., not Due)
• at least 64KB flash memory (currently although this can be reduced using static configuration)
• at least 2KB SRAM memory

TODO List

• Makefile and Arduino libraries directory
• Add event handling
• Fully test movement control
• Add advanced stepper & heater configuration
• Added thermocouple support (thermistor support already available)
• Add coding guide
• Define LCD and Rotary encoder extensions
• World domination

• System level configuration elements

  • system.board_identity
  • system.board_serialnum
  • system.hardware_name
  • system.hardware_type
  • system.hardware_rev
  • system.reset_eeprom (operation)

• Device configuration elements

  • devices.digital_input..name

  • devices.digital_input..pin

  • devices.digital_input..trigger_level

  • devices.digital_input..enable_pullup

  • devices.digital_output..name

  • devices.digital_output..pin

  • devices.digital_output..initial_state

  • devices.pwm_output..name

  • devices.pwm_output..pin

  • devices.pwm_output..use_soft_pwm

  • devices.buzzer..name

  • devices.buzzer..pin

  • devices.temp_sensor..name

  • devices.temp_sensor..pin

  • devices.temp_sensor..type

  • devices.heater..name

  • devices.heater..pin

  • devices.heater..temp_sensor

  • devices.heater..max_temp

  • devices.heater..power_on_level

  • devices.heater..use_soft_pwm

  • devices.heater..use_bang_bang

  • devices.heater..bang_bang_hysteresis

  • devices.heater..use_pid

  • devices.heater..pid_range

  • devices.heater..kp

  • devices.heater..ki

  • devices.heater..kd

  • devices.heater..dpi_do_autotune (operation)

  • devices.stepper..name

  • devices.stepper..enable_pin

  • devices.stepper..enable_invert (0 = active low, 1 = active high)

  • devices.stepper..direction_pin

  • devices.stepper..direction_invert

  • devices.stepper..step_pin

  • devices.stepper..step_invert

• Statistics elements

  • stats.rx_count
  • stats.rx_errors
  • stats.queue_memory
  • debug.stack_memory

• Diagnostic/development elements

  • debug.stack_low_water_mark