Isn't it a bit counter intuitive to use uart_set_baudrate() to set inversion? Wouldn't it be better to have an additional low level function _uart_set_inversion(bool invert) that reads USC0 and clears or sets the bits for inversion?

@Jeroen88 what are you talking about, it's uart_init()

@dok-net You are right, my mistake... :)

The CI failure is (again) nothing to do with the PR, but network / setup related?

Looks like Sphinx (the doc generator) is barfing again on installation.

#6817 will make CI work again, then you can update and the CI should then pass.

This is not documented @ https://arduino-esp8266.readthedocs.io/en/latest/reference.html#serial ? Had to read PR to figure out usage. Found no other leads searching on Google.

Serial.begin(115200, SERIAL_8N1, SERIAL_FULL, 1, true); // true = invert