---
tag: m0914
title: TMC Bump Sensitivity
brief: Set sensorless homing sensitivity
author: thinkyhead,mbuc
contrib: saikek, shitcreek

requires: SENSORLESS_HOMING
group: trinamic

codes: [ M914 ]

notes:
  - Set all `*_HOME_BUMP_MM` values to 0 for best results.
  - Set the default stall thresholds with `*_STALL_SENSITIVITY`.
  - |
    Compatible with TMC2130 and TMC2209.

    |Sensitivity|TMC2209|Others|
    |--|--|--|
    |LOWEST|0|+63|
    |HIGHEST|255|-64|

  - High sensitivity may produce false positives.
  - Low sensitivity may fail to trigger.

parameters:
  -
    tag: I
    optional: true
    since: 1.1.9
    description: Index for multiple steppers. (i.e., `I1` for X2, Y2, Z2; `I2` for Z3; `I3` for Z4).
    values:
      -
        unit: index
        type: int
  -
    tag: X
    optional: true
    description: Sensitivity of the X stepper driver.
    values:
      -
        type: int
  -
    tag: Y
    optional: true
    description: Sensitivity of the Y stepper driver.
    values:
      -
        type: int
  -
    tag: Z
    optional: true
    description: Sensitivity of the Z stepper driver.
    values:
      -
        type: int

Value Ranges:
    - TMC2208: from 0..255
    - TCM2130: from -64..+63

examples:

---

Some TMC stepper drivers can detect when they bump into something that causes them to stop moving. This feature is so sensitive that it can actually take the place of traditional endstops. Use this command to set the bump sensitivity for the X, Y, and Z stepper drivers.