M5Stack LTE module(M8321) not communicating or responding to serial commands?

  • I'm trying to get it working at the moment, however no luck so far. From the schematic i've deduced that its operating as a generic modem, with a basic serial connection from the core to the LTE module on GPIO pins 16 and 17. However when attempting to send modem AT commands there is no response from the module?

    I am programming this in arduino, and I have set up a very simple sketch to send the commands from the stack to the LTE module

    #include <M5Stack.h>

    void setup() {
    Serial.begin(9600); // set up serial
    Serial2.begin(9600, SERIAL_8N1, 16, 17); // set up a second serial that will comunicate directly with the LTE shield

    //set pin 2 high for using the modem (simulates a power button press)
    pinMode(2, OUTPUT);
    digitalWrite(2, 0);
    digitalWrite(2, 1);

    void loop() {

    while (Serial.available()){  // forward data from monitor to LTE module
      uint8_t recieve = Serial.read();
    while (Serial2.available()){  // forward data from LTE module to monitor


    I then manually input the AT commands and wait for a response from the board, however there is no response.

  • M5Stack

    I have an LTE Module but this is not really my field of expertise. If you supply the full code I can test on mine to see if it's an issue specific to your module. By the way what country are you in? The module may only work if your countries mobile networks are supporting the same frequency bands as the module is compatible with, please check the docs page in the product features area https://docs.m5stack.com/#/en/module/lte