Which tty is linked with MAIN_RXD (pin 74) and MAIN_TXD (pin 73) of RG255C

Technical Subjects
1

Hi,

I am using RG255C module, and we are connecting a UART line to this module via MAIN_RXD (pin 74) and MAIN_TXD (pin 73). However, I don’t know which UART line is linked to those pins.

after booting up, I see 4 lines as follows:
/dev/ttyEUD0
/dev/ttyGS0
/dev/ttyHS1 ->>> this possibly the line I want, but I try to periodically send from my uart line and not see anything from this line (by screen tool)
/dev/ttyMSM0 ->>> this is console uart (debug).

Can you help?
Do I need to modify the DTS to enable this?

BR
MEQ

2

The Main uart is already used or opened by some Quectel service.
Maybe you can check it
lsof | grep ttyHS

Do you have the source code of the RG255C?

3

Yes @Bean.Wang-Q

I can search in /dev and find that there is a device named /dev/ttyHS1.

lsof | grep ttyHS show nothing.

However, when I try to use “screen /dev/ttyHS1 115200 8N1”, it seems stuck without any message out.

I also see this part in the code I have.


/* <<< quade.qian-20230825: Support custom peripheral functions */
#if defined(QUECTEL_FEATURE_OPENLINUX)
#include "ql-sdxbaagha-cust-overlay.dtsi"
#else  /*modify by matt, for supporting to send fota urc by main uart, 2024-05-15*/
// main uart
&qupv3_se2_4uart {
	status = "okay";
	quectel,dynamic-props-main-uart = "status";
	quectel,dynamic-props-main-uart-on = "string:okay";
	quectel,default-status = "string:disabled";
};