EG915U auxilary uart

Hi there !
I can communicate with EG915U on main uart but not on auxilary uart.
I don’t find technical explanation on this issue in EG915U DS.
The actual firmware is EG915UEUABR03A01M08.

What am I missing with this aux uart ?


Quectel has QuecOpen solutions. The EG915U could also work as CPU and run programs.
If the modem just work as modem, it is not necessary to care about.

Thank you for your quick response Bean.Wang-Q.

Is that means that I can’t use aux uart in modem mode ?
Can’t it respond to any kind of command such as AT-Command ?

In my design, I would liked to yse it for At Command and the main uart juste for DATA .
Or main uart for GSM Comm and aux uart for BT Comm
Is it impossible ?


Do you need two uart to send AT?
The best idea should be connect with USB and there are two virtual uart port for AT.
If no, with only main uart, you could try the CMUX.

Thanks for your advice.
So I’ll forget aux uart which is finally not usable in modem mode.

best regards