Custom Controls

OctoPrint allows you to add custom controls to the “Control” tab of its interface. Control types reach from simple buttons which trigger sending of one or more lines of GCODE to the printer over more complex controls allowing parameterization of these commands with values entered by the user to full blown GCODE script templates backed by Jinja2.

Custom controls are configured within config.yaml [1] in a controls section which basically represents a hierarchical structure of all configured custom controls of various types.

Note

To make sure that your config.yaml stays valid when adding custom controls, don’t hesitate to take a look at the YAML Primer.

The following example defines a control for enabling the cooling fan with a variable speed defined by the user (default 255 and selectable through a slider UI element) and a control for disabling the fan, all within a section named “Fan”, two example controls with multiple commands in a section “Example for multiple commands”, a command with printer feedback evaluation for the result of the M114 “Get Position” gcode inside a section named “Reporting” and finally a GCODE script including user input.

controls:
  - name: Fan
    layout: horizontal
    children:
    - name: Enable Fan
      command: M106 S%(speed)s
      input:
      - name: Speed (0-255)
        parameter: speed
        default: 255
        slider:
          min: 0
          max: 255
    - name: Disable Fan
      command: M107
  - name: Example for multiple commands
    children:
    - name: Move X (static)
      confirm: You are about to move the X axis right by 10mm with 3000mm/s.
      commands:
      - G91
      - G1 X10 F3000
      - G90
    - name: Move X (parametric)
      commands:
      - G91
      - G1 X%(distance)s F%(speed)s
      - G90
      input:
      - default: 10
        name: Distance
        parameter: distance
      - default: 3000
        name: Speed
        parameter: speed
  - name: Reporting
    children:
    - name: Get Position
      command: M114
      regex: "X:([-+]?[0-9.]+) Y:([-+]?[0-9.]+) Z:([-+]?[0-9.]+) E:([-+]?[0-9.]+)"
      template: "Position: X={0}, Y={1}, Z={2}, E={3}"
  - name: Fun stuff
    children:
    - name: Dance
      script: custom/dance.gco
      input:
      - name: Go arounds
        parameter: repetitions
        slider:
          max: 10
          min: 1
          step: 1

Adding this to config.yaml, restarting the OctoPrint server and switching to the “Control” tab within its interface yields the visual representation in Fig. 1.

The rendered output created through the example configuration

Fig. 1 The rendered output created through the example configuration

As you can see you have two basic types of control definitions here: controls that actually do something (providing a button that sends one or more commands to the printer when clicked, displaying output received from the printer) and controls that just serve as container for other controls, the latter being identified by having a children attribute wrapping more controls.

Hint

Take a look at the Custom Control Editor plugin which allows you configuring your Custom Controls through OctoPrint’s settings interface without the need to manually edit the configuration file.

Types

Let’s take a closer look at the possible attributes that are available for both basic types.

Containers

Attribute Description
children A list of children controls or containers contained within this container
name (Optional) A name to display above the container, basically a section header
layout (Optional) The layout to use for laying out the contained children, either from top to bottom (vertical) or from left to right (horizontal). Defaults to a vertical layout.

Controls

Attribute Description
name The name of the control, will be displayed either on the button if it’s a control sending a command or as a label for controls which only display output.
command (Optional) A single GCODE command to send to the printer. Will be rendered as a button which sends the command to the printer upon click. The button text will be the value of the name attribute. Mutually exclusive with commands and script. The rendered button be disabled if the printer is currently offline or printing or alternatively if the requirements defined via the enabled attribute are not met.
commands (Optional) A list of GCODE commands to send to the printer. Will be rendered as a button which sends the commands to the printer upon click. The button text will be the value of the name attribute. Mutually exclusive with command and script. The rendered button will be disabled if the printer is currently offline or printing or alternatively if the requirements defined via the enabled attribute are not met.
script

(Optional) The name of a full blown GCODE script to send to the printer. Will be rendered as a button which sends the script to the printer upon click. The button text will be the value of the name attribute. Mutually exclusive with command and commands. The rendered button will be disabled if the printer is currently offline or printing or alternatively if the requirements defined via the enabled attribute are not met.

Values of input parameters will be available in the template context under the parameter variable (e.g. an input parameter speed will be available in the script template as parameter.speed). On top of that all other variables defined in the GCODE template context will be available.

See below for an example.

javascript (Optional) A JavaScript snippet to be executed when the button rendered for command or commands is clicked. This allows to override the direct sending of the command or commands to the printer with more sophisticated behaviour. The JavaScript snippet is eval’d and processed in a context where the control it is part of is provided as local variable data and the ControlViewModel is available as self.
enabled (Optional) A JavaScript snippet returning either true or false determining whether the control should be enabled or not. This allow to override the default logic for this (disabled if printer is offline or currently printing). The JavaScript snippet is eval’d and processed in a context where the control it is part of is provided as local variable data and the ControlViewModel is available as self.
input

(Optional) A list of definitions of input parameters for a command or commands, to be rendered as additional input fields. command/commands may contain placeholders to be replaced by the values obtained from the user for the defined input fields:

name: Enable Fan
command: M106 S%(speed)s
input:
  - name: Speed (0-255)
    parameter: speed
    default: 255
    slider:
        min: 0
        max: 255

In OctoPrint’s default UI input fields are always rendered left to right (inline).

input.name Name to display for the input field.
input.parameter Internal parameter name for the input field, used as a placeholder in command/commands.
input.default Default value for the input field.
input.slider (Optional) If this attribute is included, instead of an input field a slider control will be rendered. If you don’t want to define any of min, max or step, write slider: {} to render a slider based on default values.
input.slider.min (Optional) Minimum value of the slider, defaults to 0.
input.slider.max (Optional) Maximum value of the slider, defaults to 255.
input.slider.step (Optional) Step size per slider “tick”, defaults to 1.
regex (Optional) A regular expression to match against lines received from the printer to retrieve information from it (e.g. specific output). Together with template this allows rendition of received data from the printer within the UI.
template (Optional) A template to use for rendering the match of regex. May contain placeholders in Python Format String Syntax for either named groups within the regex (e.g. Temperature: {temperature} for a regex T:\s*(?P<temperature>\d+(\.\d*)) or positional groups within the regex (e.g. Position: X={0}, Y={1}, Z={2}, E={3} for a regex X:([0-9.]+) Y:([0-9.]+) Z:([0-9.]+) E:([0-9.]+)).
confirm (Optional) A text to display to the user to confirm his button press. Can be used with sensitive custom controls like changing EEPROM values in order to prevent accidental clicks. The text will be displayed in a confirmation dialog like in Fig. 2.
An example confirmation dialog

Fig. 2 An example confirmation dialog

Examples

Parameterized GCODE Script

Control definition in ~/.octoprint/config.yaml
name: Dance
script: custom/dance.gco
input:
- default: 5
  name: Go arounds
  parameter: repetitions
  slider:
    max: 10
    min: 1
    step: 1
~/.octoprint/scripts/gcode/custom/dance.gco
{% set center_x = printer_profile.volume.width / 2 %}
{% set center_y = printer_profile.volume.depth / 2 %}
{% set speed_x = printer_profile.axes.x.speed %}
{% set speed_y = printer_profile.axes.y.speed %}
{% set speed_z = printer_profile.axes.z.speed %}
M117 run {{ script.name }}
G4 P500
G1 Z10
G1 X{{ center_x }} Y{{ center_y }} F{{ speed_x }}
M117 let's dance!
G91
G1 X-1 Y-1 F{{ speed_x }}
{% for n in range(parameters.repetitions) %}
M117 and {{ n + 1 }}
  {% if n % 2 == 0 %}
    G1 Z1 F{{ speed_z }}
    G1 Z-2 F{{ speed_z }}
    G1 Z1 F{{ speed_z }}
  {% endif %}
  G1 X2 F{{ speed_x }}
  G1 Y2 F{{ speed_y }}
  G1 X-2 F{{ speed_x }}
  G1 Y-2 F{{ speed_y }}
{% endfor %}
G90
G1 X{{ center_x }} Y{{ center_y }} F{{ speed_x }}
G28 X0 Y0

Note the usage of the parameters.repetitions template variable in the GCODE script template, which will contain the value selected by the user for the “Go arounds” slider.

Footnotes

[1]For Linux that will be ~/.octoprint/config.yaml, for Windows it will be %APPDATA%/OctoPrint/config.yaml and for Mac ~/Library/Application Support/OctoPrint/config.yaml