Unable to initilze Unable to initialise Uart with LILYGO TTGO Meshtastic T-Beam V1.2

[Nico-germ]

I have bought a LILYGO TTGO Meshtastic T-Beam V1.2 module and would like to read out the GPS data with Micropython. With the examples of the Arduino IDE in C this also works.

But as soon as I try to open a Uart interface in Micropython, it does not work

from machine import UART
uart = UART(2, baudrate=9600, tx=34, rx=12)_

Thonny reports

MPY: soft reboot
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
OSError: [Errno 1] EPERM: ESP_FAIL

I have been trying to find the solution for 2 days and just can't get any further.

[robert-hh]

GPIO34 - GPIO39 are input only. You cannot use it for TX.

[Nico-germ]

Thank you for your kind advice, but the manufacturer specifies exactly 34 as TX. I have attached a picture of the board and the instructions as a picture. TX also works as 34 in the Arduino IDE. Is this a ‘speciality’ of micropython?

[robert-hh]

The picture shows that you must use tx=12 and rx=34. That connects the GPS module's TX to ESP32 RX, GPS module RX to ESP32 TX. The definition of TX and RX is sometimes confusing between the sender and receiver view.

Edit: tx=34 cannot work with a different software because it is a hardware limitation of the ESP32.

[Nico-germ]

Thank you very, very much.

-Da habe ich wohl auf dem Schlach gestanden-