Prusa Research MK4

unverified library/marlin/prusa-mk4.hal.yaml

Id	prusa-mk4
Manufacturer	Prusa Research
Model	MK4
Driver	marlin
Hazard	high
Limits	unconfirmed The library file holds suggested limits for extruder_target, bed_target, fan_speed, home (action), and no person has confirmed those limits yet. How a person confirms the limits

Control channels
Channel	Max	Step	Rate per s	Unit	Confirm	Limit
extruder_target	215	1	10	degC	confirm	suggested
bed_target	60	1	5	degC	confirm	suggested
fan_speed	100	1		%	none	suggested

Actions
Action	Arguments	Confirm	Limit
home	axes x, y, z, xy, all	confirm	suggested

Read channels
Channel	Type	Unit	Every
extruder_temp	number	degC	2 s
bed_temp	number	degC	2 s
position_z	number	mm	on request

openhal: "0.1"
device: { name: Original Prusa MK4, model: MK4, manufacturer: Prusa Research }
id: prusa-mk4
match:
  usb: ["2c99:000d"]
  usb_class: cdc
connect: { marlin: auto, baud: 115200, timeout: 5 s, settle: 2 s, autoreport: 2 s }
read:
  extruder_temp: { unit: degC, every: 2 s, range: [0, 320] }
  bed_temp: { unit: degC, every: 2 s, range: [0, 130] }
  position_z: { unit: mm }
write:
  extruder_target: { unit: degC, min: 0, max: 215, step: 1, max_change_per_s: 10, confirm: confirm, suggested: true }
  bed_target: { unit: degC, min: 0, max: 60, step: 1, max_change_per_s: 5, confirm: confirm, suggested: true }
  fan_speed: { unit: percent, min: 0, max: 100, step: 1, suggested: true }
actions:
  home:
    description: Home the axes with G28.
    args:
      axes: { type: enum, values: [x, y, z, xy, all] }
    confirm: confirm
    suggested: true
safe_state:
  - { extruder_target: 0, bed_target: 0, fan_speed: 0 }
interlocks:
  - if: "extruder_target > 0 degC"
    require: "extruder_temp < 300 degC"
    message: "The hotend reads above 300 degC. Check the thermistor before heating."
watchdog:
  heartbeat: 5 s
  on_loss: safe_state
hazard: high
notes: >-
  Suggested limits. A person must confirm every limit before this device can be written.
  The MK4 runs Prusa Buddy firmware, which grew out of Marlin and answers G-code on its USB-C port. The
  limits suit PLA, with the hotend at most 215 degC and the bed at most 60 degC. Prints from the USB stick
  are paused on the printer itself, so this file has no pause or cancel.
provenance: { source: library, by: OpenHAL starter library, at: 2026-10-25, verification: { status: unverified } }