TMC2209 - small movements after home?

MR_X

Greetings,

Firstly thank you for such amazing software!

I have been searching for an answer to this issue for a little while now, i have got some TMC2209 drivers for a Radds32/Due running Repetier 0.92 firmware on a big CoreXY.

what I am finding is that when i home X axis or Home all axis together they will all home perfectly BUT as soon as Z axis finishes the X axis will then move 3/5mm towards endstop?

Y axis does not do this and i tried changing STEPPER_HIGH_DELAY and DIRECTION_DELAY up to 20 microseconds but it does not change behavior.

I used to use RAPS128 without this issue so im assuming its related to TMC2209?

Any help is appreciated!

Repetier

Do you have autoleveling enabled? After homing head is moved to official start position and with autoleveling this can differ also I'd more expect a z move then x move. Don't think this is delay related. Not 100% sure with 0.92 as it is a bit expired and I only work on 1.0 and 2.0 but think it is similar and the end move does it.

For coreXY you should anyway add a move away from endstop after testing endstop so it is 100% sure endstop does not get triggered in normal operations.

MR_X

Thank you very much for the reply Repetier, I did not enable auto leveling. I think it is time I moved to v1 actually.

after more testing I think I have found the issue:

These Specific TMC2209 drivers (FYSETC) came from factory with 0 ohm resistors across the UART enable/PDN pin, this had forced my drivers into UART mode and I believe this was causing some interference with microstepping/steps, as the UART/PDN Pin was connected to MS3 (as soldered by factory) and im not sure RADDS is a true ground on those switches, but I have removed the resistors and I have not had issue yet.

Lesson learned hopefully, should have fully inspected the drivers before installing.