Printer Variable Reference¶

Happy Hare exposes its internal state as Klipper "printer variables" - the printer.mmu.xxx values you read in gcode_macro Jinja templates, in {% if %} conditions, or from KlipperScreen/Mainsail/Fluidd panels.

If you just want to see live values on your own printer rather than read about them, skip to MMU_DUMP_VARS below.

MMU_DUMP_VARS¶

MMU_DUMP_VARS (a gcode macro, not a Python command) dumps every printer variable this page describes, straight off the running printer:

MMU_DUMP_VARS
MMU_DUMP_VARS VERBOSE=1   # also include per-stepper and per-LED-segment objects

It works by asking Klipper's own printer object for every top-level name matching a small set of prefixes - mmu, mmu_machine, mmu_encoder *, mmu_extruder *, and with VERBOSE=1 also mmu_stepper *, mmu_leds * - then prints every key inside each as printer['name'].key = value. That search list is itself the ground truth for which top-level printer objects Happy Hare registers; see Directly-registered per-object status below for what the non-mmu/mmu_machine ones are.

Because it reads printer directly, its output is always exactly correct for your installed version - use it to check anything below that seems to disagree with what you actually see.

printer.mmu¶

The main status object. Everything in this section is printer.mmu.<key> unless noted.

Core state¶

Gate and tool maps¶

All per-gate lists here are indexed by the same global gate number used everywhere else (contiguous across units, see printer.mmu_machine below).

slicer_tool_map shape:

slicer_tool_map
  .tools.<tool_num>
    .name         {string}  filament name
    .color        {string}  "RRGGBB" or "RRGGBBAA", no leading #
    .material     {string}  material type
    .temp         {int}     print temperature
    .in_use       {bool}    referenced by this print
  .referenced_tools    {list}  tool numbers used in this print
  .initial_tool        {int}
  .purge_volumes       {list}  N×N purge volume matrix
  .total_toolchanges   {int}
  .skip_automap        {bool}  one-shot: skip automap for this print

Extruder / filament remaining¶

Sync feedback, FlowGuard and tangle prevention¶

Present when the active unit has a sync-feedback buffer and/or an encoder; {} on a unit with neither.

Sensors¶

sensors is a dict keyed by sensor name, scoped to whichever sensors are active for the currently selected gate (generic names, no gate suffix): value is True/False if the sensor is enabled (triggered or not), or None if the sensor exists but is currently disabled - see Feature: Sensors for how a sensor gets disabled and what that means for the rest of Happy Hare.

Encoder¶

encoder is only present when the active unit has one:

Per-gate arrays merged across every unit¶

NFC¶

nfc is a list of per-unit dicts, present only when at least one unit has an NFC/RFID reader configured. Each entry: {'unit': <name>, 'polling': <bool>, 'shared': {...}|None, 'gates': {<gate>: {...}}}, where each reader dict is enabled, active, alive, present, uid (the cached tag from the last read, not a live scan).

printer.mmu_machine¶

The multi-unit aggregation object. is_homed, unit, tool etc. above already account for multiple units; this object is for enumerating the units themselves.

Each unit_N dict:

Directly-registered per-object status¶

A handful of components are registered as their own top-level Klipper printer objects (in addition to being folded into printer.mmu above), named after their config section - exactly the names MMU_DUMP_VARS searches for:

Use printer.mmu.encoder for the common case (current unit's encoder, already resolved); reach for printer['mmu_encoder unit0'] directly only when you specifically need a different unit's encoder than the one currently active, since Happy Hare units can have independent, differently-named encoders.

Deprecated variables¶

Still present in printer.mmu, still computed, but superseded.

See also¶

• Developer: Klipper Events