Klipper TMC2209 Sensorless Homing Issue on Z-Axis

This repository serves as a central point for troubleshooting sensorless homing issues on the Z-axis using TMC2209 stepper drivers in a Klipper firmware setup. The configuration for the X and Y axes works as expected, but the Z-axis encounters persistent false triggering during the retract phase of homing, despite various tuning efforts.

Problem Overview

• Endstop error: The Z-axis shows "Endstop Z still triggered after retract."
• TMC2209 driver_SGTHRS sensitivity tuning: Adjusted between 10 to 300 but still encountering issues.
• Wiring and diag_pin configuration: Potential issues with diag_pin configuration.

Configuration Summary

Current Z-axis Configuration:

[tmc2209 stepper_z]
uart_pin: PC5
run_current: 0.8  # Set down to prevent motor stress (some motors have 0.8A versions)
hold_current: 0.5
interpolate: True
stealthchop_threshold: 1
driver_SGTHRS: 80  # Adjust sensitivity if needed
diag_pin: ^PC3

[tmc2209 stepper_x]
uart_pin: PB9
run_current: 0.9
hold_current: 0.8
interpolate: True
stealthchop_threshold: 1
driver_SGTHRS: 100
diag_pin: ^PC0

[tmc2209 stepper_y]
uart_pin: PD2
run_current: 1.4
hold_current: 0.8
interpolate: True
stealthchop_threshold: 1
driver_SGTHRS: 115
diag_pin: ^PB8