Using EC200U-CN Auxiliary UART for AT Commands and PPP Connection with Microcontroller

IoT Modules LTE Standard Module
, ,
1

Hello Quectel Team,

I am currently working on a project using the EC200U-CN 4G LTE module with a microcontroller (ESP32-S3). I am already able to establish a PPP connection and communicate using the main UART (UART1).

Now, I would like to know if it is possible to use the auxiliary UART interface of the EC200U-CN module for the following purposes:

  • Sending AT commands (for control and debugging)
  • Establishing or maintaining a PPP data connection

My main goal is to separate the AT command interface from the PPP data interface, so that I can monitor or send other commands while the data connection is active.

Could you please confirm:

  1. Whether the auxiliary UART supports AT command communication.
  2. If the PPP connection can be established or routed through the auxiliary UART instead of the main UART.
  3. If any AT commands or configuration settings are required to enable the auxiliary UART for AT command usage.

Any reference documentation or example configurations would be highly appreciated.

Thank you,
Harshad

EC200U Series - GPS NMEA and PPP Conflict on Same UART Port
2

Hi,
Thank you for your detailed description.
The auxiliary UART refers to the debug UART, right?
You can utilize the CMUX function to multiplex the main serial port. I sent you a document privately, you can refer to it.

3

Hi harshad, can i know the code description of establishing the internet over pppos protocol by using libraries not AT commands?

4

Here is the example code from ESP32.
esp-idf/examples/protocols/pppos_client at release/v4.4 · espressif/esp-idf