I have a somewhat interesting issue.

Recently I’ve installed the BTT SFS v2 filament sensor, which detects both if filament is present and if there is a jam or not. The jam detection works with an encoder that spins whenever filament is running through it.

Pressure advance however works by slowing down and speeding up extrusion based on motion of the nozzle to prevent bulging and oozing.

This however triggers false positives in the jam detection. Without pressure advance it works fine.

Does anyone have experience with this? Below is example code of my Klipper config related to the jam sensor. Raising the detection length from 2.88 to 10 did not solve it and I don’t want to put excessive numbers there.

[filament_motion_sensor encoder_sensor]
switch_pin: gpio_xx
detection_length: 10
extruder: extruder
pause_on_runout: False
runout_gcode:
  PAUSE # [pause_resume] is required in printer.cfg
  M117 Filament encoder runout
#insert_gcode:
  #M117 Filament encoder inserted