klipper/docs/Command_Templates.md

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This document provides information on implementing G-Code command sequences in gcode_macro (and similar) config sections.

G-Code Macro Naming

Case is not important for the G-Code macro name - MY_MACRO and my_macro will evaluate the same and may be called in either upper or lower case. If any numbers are used in the macro name then they must all be at the end of the name (eg, TEST_MACRO25 is valid, but MACRO25_TEST3 is not).

Formatting of G-Code in the config

Indentation is important when defining a macro in the config file. To specify a multi-line G-Code sequence it is important for each line to have proper indentation. For example:

[gcode_macro blink_led]
gcode:
  SET_PIN PIN=my_led VALUE=1
  G4 P2000
  SET_PIN PIN=my_led VALUE=0

Note how the gcode: config option always starts at the beginning of the line and subsequent lines in the G-Code macro never start at the beginning.

Save/Restore state for G-Code moves

Unfortunately, the G-Code command language can be challenging to use. The standard mechanism to move the toolhead is via the G1 command (the G0 command is an alias for G1 and it can be used interchangeably with it). However, this command relies on the "G-Code parsing state" setup by M82, M83, G90, G91, G92, and previous G1 commands. When creating a G-Code macro it is a good idea to always explicitly set the G-Code parsing state prior to issuing a G1 command. (Otherwise, there is a risk the G1 command will make an undesirable request.)

A common way to accomplish that is to wrap the G1 moves in SAVE_GCODE_STATE, G91, and RESTORE_GCODE_STATE. For example:

[gcode_macro MOVE_UP]
gcode:
  SAVE_GCODE_STATE NAME=my_move_up_state
  G91
  G1 Z10 F300
  RESTORE_GCODE_STATE NAME=my_move_up_state

The G91 command places the G-Code parsing state into "relative move mode" and the RESTORE_GCODE_STATE command restores the state to what it was prior to entering the macro. Be sure to specify an explicit speed (via the F parameter) on the first G1 command.

Template expansion

The gcode_macro gcode: config section is evaluated using the Jinja2 template language. One can evaluate expressions at run-time by wrapping them in { } characters or use conditional statements wrapped in {% %}. See the Jinja2 documentation for further information on the syntax.

This is most often used to inspect parameters passed to the macro when it is called. These parameters are available via the params pseudo-variable. For example, if the macro:

[gcode_macro SET_PERCENT]
gcode:
  M117 Now at { params.VALUE|float * 100 }%

were invoked as SET_PERCENT VALUE=.2 it would evaluate to M117 Now at 20%. Note that parameter names are always in upper-case when evaluated in the macro and are always passed as strings. If performing math then they must be explicitly converted to integers or floats.

An example of a complex macro:

[gcode_macro clean_nozzle]
gcode:
  SAVE_GCODE_STATE NAME=clean_nozzle_state
  G90
  G0 Z15 F300
  {% for wipe in range(8) %}
    {% for coordinate in [(275,4),(235,4)] %}
      G0 X{coordinate[0]} Y{coordinate[1] + 0.25 * wipe} Z9.7 F12000
    {% endfor %}
  {% endfor %}
  RESTORE_GCODE_STATE NAME=clean_nozzle_state

The "printer" Variable

It is possible to inspect (and alter) the current state of the printer via the printer pseudo-variable. For example:

[gcode_macro slow_fan]
gcode:
  M106 S{ printer.fan.speed * 0.9 * 255}

Important! Macros are first evaluated in entirety and only then are the resulting commands executed. If a macro issues a command that alters the state of the printer, the results of that state change will not be visible during the evaluation of the macro. This can also result in subtle behavior when a macro generates commands that call other macros, as the called macro is evaluated when it is invoked (which is after the entire evaluation of the calling macro).

By convention, the name immediately following printer is the name of a config section. So, for example, printer.fan refers to the fan object created by the [fan] config section. There are some exceptions to this rule - notably the gcode_move and toolhead objects. If the config section contains spaces in it, then one can access it via the [ ] accessor - for example: printer["generic_heater my_chamber_heater"].temperature.

The following are common printer attributes:

  • printer.fan.speed: The fan speed as a float between 0.0 and 1.0. This is also available on "heater_fan", "fan_generic", and "controller_fan" config sections (eg, printer["fan_generic my_fan"].speed).
  • printer.fan.rpm: The measured fan speed in rotations per minute if the fan has a tachometer_pin defined. This is also available on "heater_fan", "fan_generic", and "controller_fan" config sections (eg, printer["fan_generic my_fan"].rpm).
  • printer.gcode_move.gcode_position: The current position of the toolhead relative to the current G-Code origin. That is, positions that one might directly send to a G1 command. It is possible to access the x, y, z, and e components of this position (eg, printer.gcode_move.gcode_position.x).
  • printer.gcode_move.position: The last commanded position of the toolhead using the coordinate system specified in the config file. It is possible to access the x, y, z, and e components of this position (eg, printer.gcode_move.position.x).
  • printer.gcode_move.homing_origin: The origin of the gcode coordinate system (relative to the coordinate system specified in the config file) to use after a G28 command. The SET_GCODE_OFFSET command can alter this position. It is possible to access the x, y, and z components of this position (eg, printer.gcode_move.homing_origin.x).
  • printer.gcode_move.speed: The last speed set in a G1 command (in mm/s).
  • printer.gcode_move.speed_factor: The "speed factor override" as set by an M220 command. This is a floating point value such that 1.0 means no override and, for example, 2.0 would double requested speed.
  • printer.gcode_move.extrude_factor: The "extrude factor override" as set by an M221 command. This is a floating point value such that 1.0 means no override and, for example, 2.0 would double requested extrusions.
  • printer.gcode_move.absolute_coordinates: This returns True if in G90 absolute coordinate mode or False if in G91 relative mode.
  • printer.gcode_move.absolute_extrude: This returns True if in M82 absolute extrude mode or False if in M83 relative mode.
  • printer["gcode_macro <macro_name>"].<variable>: The current value of a gcode_macro variable.
  • printer.<heater>.temperature: The last reported temperature (in Celsius as a float) for the given heater. Example heaters are: extruder, extruder1, heater_bed, heater_generic <config_name>.
  • printer.<heater>.target: The current target temperature (in Celsius as a float) for the given heater.
  • printer.<heater>.power: The last setting of the PWM pin (a value between 0.0 and 1.0) associated with the heater.
  • printer.idle_timeout.state: The current state of the printer as tracked by the idle_timeout module. It is one of the following strings: "Idle", "Printing", "Ready".
  • printer.idle_timeout.printing_time: The amount of time (in seconds) the printer has been in the "Printing" state (as tracked by the idle_timeout module).
  • printer.pause_resume.is_paused: Returns true if a PAUSE command has been executed without a corresponding RESUME.
  • printer.toolhead.position: The last commanded position of the toolhead relative to the coordinate system specified in the config file. It is possible to access the x, y, z, and e components of this position (eg, printer.toolhead.position.x).
  • printer.toolhead.extruder: The name of the currently active extruder. For example, one could use printer[printer.toolhead.extruder].target to get the target temperature of the current extruder.
  • printer.toolhead.homed_axes: The current cartesian axes considered to be in a "homed" state. This is a string containing one or more of "x", "y", "z".
  • printer.toolhead.axis_minimum, printer.toolhead.axis_maximum: The axis travel limits (mm) after homing. It is possible to access the x, y, z components of this limit value (eg, printer.toolhead.axis_minimum.x, printer.toolhead.axis_maximum.z).
  • printer.toolhead.max_velocity, printer.toolhead.max_accel, printer.toolhead.max_accel_to_decel, printer.toolhead.square_corner_velocity: The current printing limits that are in effect. This may differ from the config file settings if a SET_VELOCITY_LIMIT (or M204) command alters them at run-time.
  • printer.heaters.available_heaters: Returns a list of all currently available heaters by their full config section names, e.g. ["extruder", "heater_bed", "heater_generic my_custom_heater"].
  • printer.heaters.available_sensors: Returns a list of all currently available temperature sensors by their full config section names, e.g. ["extruder", "heater_bed", "heater_generic my_custom_heater", "temperature_sensor electronics_temp"].
  • printer.query_endstops.last_query["<endstop>"]: Returns True if the given endstop was reported as "triggered" during the last QUERY_ENDSTOP command. Note, due to the order of template expansion (see above), the QUERY_ENDSTOP command must be run prior to the macro containing this reference.
  • printer.probe.last_query: Returns True if the probe was reported as "triggered" during the last QUERY_PROBE command. Note, due to the order of template expansion (see above), the QUERY_PROBE command must be run prior to the macro containing this reference.
  • printer.probe.last_z_result: Returns the Z result value of the last PROBE command.
  • printer.configfile.settings.<section>.<option>: Returns the given config file setting (or default value) during the last software start or restart. (Any settings changed at run-time will not be reflected here.)
  • printer.configfile.config.<section>.<option>: Returns the given raw config file setting as read by Klipper during the last software start or restart. (Any settings changed at run-time will not be reflected here.) All values are returned as strings.
  • printer["gcode_macro <macro_name>"].<variable>: The current value of a gcode_macro variable.
  • printer.webhooks.state: Returns a string indicating the current Klipper state. Possible values are: "ready", "startup", "shutdown", "error".
  • printer.webhooks.state_message: A human readable string giving additional context on the current Klipper state.
  • printer.display_status.progress: The progress value of the last M73 G-Code command (or printer.virtual_sdcard.progress if no recent M73 received).
  • printer.display_status.message: The message contained in the last M117 G-Code command.
  • printer["filament_switch_sensor <config_name>"].enabled: Returns True if the switch sensor is currently enabled.
  • printer["filament_switch_sensor <config_name>"].filament_detected: Returns True if the sensor is in a triggered state.
  • printer.virtual_sdcard.is_active: Returns True if a print from file is currently active.
  • printer.virtual_sdcard.progress: An estimate of the current print progress (based of file size and file position).
  • printer.virtual_sdcard.file_position: The current position (in bytes) of an active print.
  • printer.print_stats.filename, printer.print_stats.total_duration, printer.print_stats.print_duration, printer.print_stats.filament_used, printer.print_stats.state, printer.print_stats.message: Estimated information about the current print when a virtual_sdcard print is active.
  • printer.firmware_retraction.retract_length, printer.firmware_retraction.retract_speed, printer.firmware_retraction.unretract_extra_length, printer.firmware_retraction.unretract_speed: The current settings for the firmware_retraction module. These settings may differ from the config file if a SET_RETRACTION command alters them.
  • printer["bme280 <sensor_name>"].temperature, printer["bme280 <sensor_name>"].humidity, printer["bme280 <sensor_name>"].pressure, printer["bme280 <sensor_name>"].gas: The last read values from the sensor.
  • printer["htu21d <sensor_name>"].temperature, printer["htu21d <sensor_name>"].humidity: The last read values from the sensor.
  • printer["lm75 <sensor_name>"].temperature: The last read temperature from the sensor.
  • printer["temperature_host <sensor_name>"].temperature: The last read temperature from the sensor.
  • printer["temperature_sensor <config_name>"].temperature: The last read temperature from the sensor.
  • printer["temperature_sensor <config_name>"].measured_min_temp, printer["temperature_sensor <config_name>"].measured_max_temp: The lowest and highest temperature seen by the sensor since the Klipper host software was last restarted.
  • printer["temperature_fan <config_name>"].temperature: The last read temperature from the sensor.
  • printer["temperature_fan <config_name>"].target: The target temperature for the fan.
  • printer["output_pin <config_name>"].value: The "value" of the pin, as set by a SET_PIN command.
  • printer["servo <config_name>"].value: The last setting of the PWM pin (a value between 0.0 and 1.0) associated with the servo.
  • printer.bed_mesh.profile_name, printer.bed_mesh.mesh_min, printer.bed_mesh.mesh_max, printer.bed_mesh.probed_matrix, printer.bed_mesh.mesh_matrix: Information on the currently active bed_mesh.
  • printer.hall_filament_width_sensor.is_active: Returns True if the sensor is currently active.
  • printer.hall_filament_width_sensor.Diameter, printer.hall_filament_width_sensor.Raw: The last read values from the sensor.
  • printer.mcu.mcu_version: The Klipper code version reported by the micro-controller.
  • printer.mcu.mcu_build_versions: Information on the build tools used to generate the micro-controller code (as reported by the micro-controller).
  • printer.mcu.mcu_constants.<constant_name>: Compile time constants reported by the micro-controller. The available constants may differ between micro-controller architectures and with each code revision.
  • printer.mcu.last_stats.<statistics_name>: Statistics information on the micro-controller connection.
  • printer.system_stats.sysload, printer.system_stats.cputime, printer.system_stats.memavail: Information on the host operating system and process load.

The above list is subject to change - if using an attribute be sure to review the Config Changes document when upgrading the Klipper software. The above list is not exhaustive. Other attributes may be available (via get_status() methods defined in the software). However, undocumented attributes may change without notice in future Klipper releases.

Actions

There are some commands available that can alter the state of the printer. For example, { action_emergency_stop() } would cause the printer to go into a shutdown state. Note that these actions are taken at the time that the macro is evaluated, which may be a significant amount of time before the generated g-code commands are executed.

Available "action" commands:

  • action_respond_info(msg): Write the given msg to the /tmp/printer pseudo-terminal. Each line of msg will be sent with a "// " prefix.
  • action_raise_error(msg): Abort the current macro (and any calling macros) and write the given msg to the /tmp/printer pseudo-terminal. The first line of msg will be sent with a "!! " prefix and subsequent lines will have a "// " prefix.
  • action_emergency_stop(msg): Transition the printer to a shutdown state. The msg parameter is optional, it may be useful to describe the reason for the shutdown.
  • action_call_remote_method(method_name): Calls a method registered by a remote client. If the method takes parameters they should be provided via keyword arguments, ie: action_call_remote_method("print_stuff", my_arg="hello_world")

Variables

The SET_GCODE_VARIABLE command may be useful for saving state between macro calls. Variable names may not contain any upper case characters. For example:

[gcode_macro start_probe]
variable_bed_temp: 0
gcode:
  # Save target temperature to bed_temp variable
  SET_GCODE_VARIABLE MACRO=start_probe VARIABLE=bed_temp VALUE={printer.heater_bed.target}
  # Disable bed heater
  M140
  # Perform probe
  PROBE
  # Call finish_probe macro at completion of probe
  finish_probe

[gcode_macro finish_probe]
gcode:
  # Restore temperature
  M140 S{printer["gcode_macro start_probe"].bed_temp}

Be sure to take the timing of macro evaluation and command execution into account when using SET_GCODE_VARIABLE.

Delayed Gcodes

The [delayed_gcode] configuration option can be used to execute a delayed gcode sequence:

[delayed_gcode clear_display]
gcode:
  M117

[gcode_macro load_filament]
gcode:
 G91
 G1 E50
 G90
 M400
 M117 Load Complete!
 UPDATE_DELAYED_GCODE ID=clear_display DURATION=10

When the load_filament macro above executes, it will display a "Load Complete!" message after the extrusion is finished. The last line of gcode enables the "clear_display" delayed_gcode, set to execute in 10 seconds.

The initial_duration config option can be set to execute the delayed_gcode on printer startup. The countdown begins when the printer enters the "ready" state. For example, the below delayed_gcode will execute 5 seconds after the printer is ready, initializing the display with a "Welcome!" message:

[delayed_gcode welcome]
initial_duration: 5.
gcode:
  M117 Welcome!

Its possible for a delayed gcode to repeat by updating itself in the gcode option:

[delayed_gcode report_temp]
initial_duration: 2.
gcode:
  {action_respond_info("Extruder Temp: %.1f" % (printer.extruder0.temperature))}
  UPDATE_DELAYED_GCODE ID=report_temp DURATION=2

The above delayed_gcode will send "// Extruder Temp: [ex0_temp]" to Octoprint every 2 seconds. This can be canceled with the following gcode:

UPDATE_DELAYED_GCODE ID=report_temp DURATION=0

Save Variables to disk

If a save_variables config section has been enabled, SAVE_VARIABLE VARIABLE=<name> VALUE=<value> can be used to save the variable to disk so that it can be used across restarts. All stored variables are loaded into the printer.save_variables.variables dict at startup and can be used in gcode macros. to avoid overly long lines you can add the following at the top of the macro:

{% set svv = printer.save_variables.variables %}

As an example, it could be used to save the state of 2-in-1-out hotend and when starting a print ensure that the active extruder is used, instead of T0:

[gcode_macro T1]
gcode:
  ACTIVATE_EXTRUDER extruder=extruder1
  SAVE_VARIABLE VARIABLE=currentextruder VALUE='"extruder1"'

[gcode_macro T0]
gcode:
  ACTIVATE_EXTRUDER extruder=extruder
  SAVE_VARIABLE VARIABLE=currentextruder VALUE='"extruder"'

[gcode_macro START_GCODE]
gcode:
  {% set svv = printer.save_variables.variables %}
  ACTIVATE_EXTRUDER extruder={svv.currentextruder}