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FOCI

Bring-up

Requires the printer.cfg from Configuration and a running Klipper. Run each command below once per axis (stepper_x, then stepper_y).

Self-test

Section titled “Self-test”
FOCI_SELFTEST STEPPER=stepper_x

Checks board and wiring health, independent of motor tuning. A passing run:

  ADC calibration .................... PASS (offset_i0=..., offset_i1=...)
  Motor coil A ....................... PASS (current=...)
  Motor coil B ....................... PASS (current=...)
  Phase wiring ....................... PASS
  Encoder ............................ PASS
  Encoder direction .................. PASS
  R-model evidence ................... PASS
  L control-model evidence ........... PASS
FOCI_SELFTEST stepper_x: SUCCEEDED, all 8 stages passed.

Stage reference:

Stage Checks On failure
ADC calibration TMC4671 current-sense offsets Board or chip fault, not wiring
Motor coil A / B Each coil draws current when driven Open or shorted phase. Check the motor connector
Phase wiring Coils aren’t cross-wired to the wrong driver channel Swap the two motor phase pairs at the connector
Encoder Encoder signal present and readable Encoder cable disconnected or miswired
Encoder direction Encoder counts the expected direction for commanded current Not a wiring fault. Console reports encoder_direction looks inverted. Set encoder_direction: reversed in [foci stepper_x] and re-run
R-model / L control-model evidence Resistance/inductance measurement quality Motor moved during the test. Ensure it’s unloaded and free to turn, then re-run

Setup

Section titled “Setup”
FOCI_SETUP STEPPER=stepper_x

Identifies motor resistance and inductance and applies current gains. Defaults to the balanced profile. Pass PROFILE=conservative or PROFILE=stiff to change it.

FOCI_SETUP stepper_x: SUCCEEDED, resistance/inductance identified, current gains applied.

Warnings

Section titled “Warnings”

If the measurement wasn’t fully clean, the console also prints a warning line, for example:

FOCI stepper_x inner confidence: coil R mismatch, theta/tau ratio
Warning Cause Action
coil R mismatch, coil control-model tau mismatch, theta/tau ratio Electrical asymmetry between the two coils Check the connector, re-run
current gains fell back to defaults, host-default confidence (no fresh measurement) Identification run didn’t get a clean measurement Ensure the motor is unloaded and free to move, re-run

A warning doesn’t block the axis from working. Firmware tunes it more conservatively than a clean measurement would allow, so you can proceed to bring-up the next axis or start homing. To clear a warning instead, apply the fix from the table above and re-run FOCI_SETUP before SAVE_CONFIG.

Save

Section titled “Save”
SAVE_CONFIG

Persists the identified resistance, inductance, and current gains to printer.cfg, and restarts Klipper. Run self-test and setup for both axes first, so one SAVE_CONFIG covers both.

First home

Section titled “First home”

Keep a hand on emergency stop (M112, or your printer’s physical switch) in case an axis moves the wrong way or doesn’t stop at the endstop.

G28 X
G28 Y

Each axis moves and homes correctly, but isn’t tuned for production motion yet. Continue with Tuning before printing.