@t3p3tony what do ESP_DATA_RDY and NPCS0 for? can this to pin connect to GND or 3.3V pull up, thanks for reply

@jay_s_uk thanks

@dc42 I test with my duet2 wifi board.
M575 P2 B57600 and reply "Error: M575: parameter 'P' too high".
Where do I miss ?

@dc42 which version have second uart, 3.2.2? or 3.3?

I have a stm32 board in hand, and want to send gcode through the paneldue port(also known as aux1 port). When I sent single gcode like "G1 X10 Y40", it works well. But when I wrote a program to send a lot of gcode through this port, it hanppens that some gcode lost randomly.
I read the gcode dictionary and there it mentioned "flow control", but I don't know what should I do.
Can somebody come from the same question ?

learning.

I also have the similary question，it‘s luck to see you here