Problems with UART connection with SKR Mini E3 V2 and BTT Pi V1.2

General Discussion
1

Basic Information:

Printer Model: DIY Core XY
MCU / Printerboard: SKR Mini E3 V2
Host / SBC BTT PI V1.2
klippy.log
klippy (1).log (1.6 MB)

Fill out above information and in all cases attach your klippy.log file (use zip to compress it, if too big). Pasting your printer.cfg is not needed
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Describe your issue:

After i finished building printer.cfg and trying to home my X and Y axis (Sensorless Homing) i got this ERROR from Klipper ‘Unable to read tmc uart ‘stepper_y’ register IFCNT’, i tryed to find a solution everywhere but to no luck. I would really appreciate any help.
I have Jumper on both X and Y axis for Sensorless homing on board, Z axis is with Endstop switches and it is working perfectly.
…

2

Where did you get the pin information for the TMC2209s on the board?

The failure is indicating that Klipper can’t communicate with the TMC2209s on the board via their serial port.

I just looked at your klippy.log and you have:

[tmc2209 stepper_x]
uart_pin = PA3
diag_pin = PC0
uart_address = 0
run_current = 0.580
hold_current = 0.500
stealthchop_threshold = 999999

[tmc2209 stepper_y]
uart_pin = PA2
diag_pin = PC1
uart_address = 2
run_current = 0.580
hold_current = 0.500
stealthchop_threshold = 999999

[tmc2209 stepper_z]
uart_pin = PC11
tx_pin = PC10
uart_address = 1
run_current = 0.580
hold_current = 0.500
stealthchop_threshold = 999999

You have different values for the uart_pin when it should be TX4/PC10 for all of them.

I did a quick check of the specified EN/DIR/STEP pins and they look okay.

You should also add a [TMC2209 extruder] statement.

3

Thank you for your fast reply, i will try it tomorrow with these changes, it is my first klipper build so i asked ChatGPT for some help, but it was not so much of a help, it made more problems and in the end, i ended here…:grin: