BG77xA-GL EMUX/ModemManager Integration

IoT Modules LPWA Module
1

Hello All,

One of my projects requires BG770A-GL EMUX integration with systemd ModemManager. I have obtained the BG770A-GL EMUX Linux drivers and successfully compiled them for my ARM-based Embedded Linux System.

After running the EMUX utility, virtual ports (/dev/ttyMUX[0-3]) are created, allowing communication with the BG770A-GL module via AT commands.

root@localhost:~# ./mux /dev/ttyUSB0 /dev/ttyMUX 115200
Connected to serial device: /dev/ttyUSB0
Chosen baudrate: 115200
Created virtual port: /dev/ttyMUX0
Created virtual port: /dev/ttyMUX1
Created virtual port: /dev/ttyMUX2
Created virtual port: /dev/ttyMUX3
root@localhost:~# ls -l /dev/ttyMUX*
lrwxrwxrwx 1 root root 10 May  2 11:43 /dev/ttyMUX0 -> /dev/pts/2
lrwxrwxrwx 1 root root 10 May  2 11:43 /dev/ttyMUX1 -> /dev/pts/3
lrwxrwxrwx 1 root root 10 May  2 11:43 /dev/ttyMUX2 -> /dev/pts/4
lrwxrwxrwx 1 root root 10 May  2 11:43 /dev/ttyMUX3 -> /dev/pts/5
root@localhost:~#

However, ModemManager encounters difficulty communicating through /dev/pts/x devices, as it relies on udev rules which do not recognize these devices.

Could anyone provide suggestions on how to integrate ttyMUX with ModemManager effectively?

Any assistance would be greatly appreciated.

Cheers,

2

Or if any plans to add support for EMUX in the n_gsm kernel driver? That will help us and everyone.

3

ModemManager do not support the EMUX virtual port.

You can use the usb port. And add the udev rules.

4

@Bean.Wang-Q

Thanks for your feedback.

Yes, I’m aware of that and as a alternative solution it is best if Quectel can add support for EMUX in the n_gsm kernel driver, that will solve many problems. Just like CMUX CMUX/n_gsm

5

@Bean.Wang-Q

Any thoughts on getting Quectel’s EMUX driver added in the n_gsm kernel driver?

6

But mux seems not a Linux kernel driver.

7

@Bean.Wang-Q
CMUX is in n_gsm kernel driver so similar stack but of EMUX.