SKR 1.4 Turbo with BTT PI v1.2 and Klipper

[Ignat]

I have SKR 1.4 Turbo and BTT PI works well with klipper trough USB.

I try to connect thees trough UART, so I:
- edit /boot/BoardEnv.txt changing "console=display" to "console=serial" and reboot BTT PI
- build and flash klipper firmware changing Comunication interface from "USB" to "Serial (on UART0 P0.3/P0.2)" cause I use TFT plug
- connect BTT PI pins GND-PH0-PH1 (6-8-10) to SKR pins GND-TX0-RX0
- change klipper's printer.cfg setting [mcu] serial: /dev/ttyS0
but I have communication error:

mcu 'mcu': Timeout on connect
mcu 'mcu': Wait for identify_response
Traceback (most recent call last):
  File "/home/biqu/klipper/klippy/serialhdl.py", line 68, in _get_identify_data
    params = self.send_with_response(msg, 'identify_response')
  File "/home/biqu/klipper/klippy/serialhdl.py", line 261, in send_with_response
    return src.get_response([cmd], self.default_cmd_queue)
  File "/home/biqu/klipper/klippy/serialhdl.py", line 318, in get_response
    self.serial.raw_send_wait_ack(cmds[-1], minclock, reqclock,
  File "/home/biqu/klipper/klippy/serialhdl.py", line 253, in raw_send_wait_ack
    self._error("Serial connection closed")
  File "/home/biqu/klipper/klippy/serialhdl.py", line 61, in _error
    raise error(self.warn_prefix + (msg % params))
serialhdl.error: mcu 'mcu': Serial connection closed

What can I do else or how to diagnose the problem?

[Wil]

Don't have the gpio pin out infront of me but do you have the wires rx to tx and TX to rx? Won't work if rx to rx