Invert_x_dir - Micro SD card reader not working

I am running a Tevo Nereus with a Robin Nano V1.1 board.

I had to replace 2 stepper motors (x and y) but they run opposite to the ones I replaced. I am now using LV8729 (I have ordered some TMC2208s but they are not here yet).

I need to reverse them. If I could use the SD card reader I would change the invert_x_dir and invert_y_dir settings. Unfortunately the only access I have to the printer is thru the front panel and using OctoPi.

The basic question is; is there a way to change the invert_x_dir and invert_y_dir thru OctoPi/OctoPrint .

What did you already try to solve it?
I havent been able to find an 'm' code to change these settings. I have changed the Printer Profile inverting control on the x and y axis ). I have ordered the optional USB connector accessory and am hoping I can flash the firmware with it but it is coming from China...

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, what kind of hardware precisely, ...)

I have OctoPrint 1.4.0 and OctoPi 0.17.0 on a raspberryPi 4 B Rev 1.1 2gb

OctoPrint should not be used as an alternative to fix your hardware or firmware.

Even if you could reverse all the coordinates of gcode sent to the printer, homing would still be broken because it would hit the wrong endstops.

I don't know what connectors you have on the steppers, but it could be as easy as inserting them into the controller board upside-down.


I was thinking of something more in the lines of, for instance, M301 will let me set the PID so maybe M would let me invert the directions and then M500 would let me save it and I would be done.
I want to replace the board but the Nereus is limited (by space) to a 3inch by 4in board (unless I re-orient the power supply and other connections ). I hate to replace an old, obsolete board with another of the same.
I am hoping the USB accessory I ordered will be a temporary fix. I am not trying to 'reverse each GCODE command'

Inverting the stepper direction is really a hardware/firmware topic. This should be done at hardware or firmware level. It's more easy, more reliable and more save than fumbling around with gcode commands.

I would think M301 etc / M500 is firmware...

These are commands that can change some settings in the firmware.
These are for changing parameters for the (almost) daily use.
Stepper direction is a basic setting that, when the printer hardware has not changed, would not change again. If so, there would be a gcode command to change the stepper direction.

But one thing comes in mind:
You could try set negative values for steps per millimeter settings. with M92.
But I don't know if negative values are accepted.

Thanks, I gave up and ordered a new card - now I just have to hope I can make it fit in the enclosure...

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