Homing direction wrong....

Homing Wrong Direction

BTT Mini E3 V2, BTT TfT32, BL Touch (Triangle Labs)

X and Y home correctly and move in the right directions.

Using Pronterface or the TFT the Z axis moves in the correct direction.

M119 :-
With power on to the printer M119 shows X and Y open, Z triggered.

BL Touch :-
The BL Touch passes the self test built into the TFT.

Withe the "Probe up" M119 returns Z Triggered but axis moves in correct direction from. Command from tft or pronterface.
With the "Probe down" M119 returns Open but axis moves in correct direction. Command from tft or pronterface.

In Marlin 2 the Z home direction is set to Z Min this is a requirement it won't compile if it's Zmax.

If I home Z the axis goes in the wrong direction!!!

This seems to be something that has occured on many occasions to lots of people but so far I have no found a clear fix.

I have everything else working and calibrated once this is sorted my printer will be running

Any help appreciated.

Thanks aamcle

99% of people enable Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN when the probe is fully plugged into the probe port and not using the z_min endstop plug as they have declared

Edited 1 time(s). Last edit at 09/29/2022 08:17AM by Dust.

I'm not sure what you mean, I have the bt touch plugged into the dedicated socket.
Do I comment out the z min endstop plug and enable the z min endstop pin?

I'll try that, I'm nearly frustrated enough to go back to a mechanical switch and level the bed by hand

If your probe is not plugged into the z_min plug you must disable #define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
Instead enable #define USE_PROBE_FOR_Z_HOMING

Marlin then looks at Z_MIN_PROBE_PIN not the Z_MIN_PIN (as defined your your motherboard pin.h file) when homing Z with the probe.

Edited 1 time(s). Last edit at 09/29/2022 10:45AM by Dust.

Progress!

It's going the right way triggering the Bl Touch but and there always seems to be a but....

Using ABL the bed comes up triggers the probe then drops about 10mm moves to 0,0 tries and fails to probe ( I think the gap to the bed is too great) and the drops the bed about a further 10mm.

I didn't get the chance go set the Z offset the bed just dropped.....

There is still some flaw in my settings

Update.

I tried again in Marlin mode and it works, the Touch screen seems to issue a M46 which returnes as unknown.

I'm quite content to use the encoder

Many Thanks

Edited 1 time(s). Last edit at 09/29/2022 01:41PM by aamcle.