CORES3 with NB-IOT

markpro

Hi!

I have a CoreS3 with a COM.NB-IoT. Somehow I can;t get the SIM7020 get to work. Does someone have a example code? I have changed the dipswitches to:

#define SerialAT Serial1
#define MODEM_TX 13
#define MODEM_RX 7

From the IoT_BASE_SIM7020 I have extracted the TinyGSM code for the SIM7020. But as mentioned, I can not get it to work. Does someone have a full working example? I do have the COMMU module on Serial2 on:

#define Serial485 Serial2
#define RS485_TX 17
#define RS485_RX 18

TinyGsm modem(SerialAT,0);
void setupModem() {

  pinMode(2, OUTPUT);
  digitalWrite(2, 0);
  
  SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
  TinyGsmAutoBaud(SerialAT, GSM_AUTOBAUD_MIN, GSM_AUTOBAUD_MAX);
  
  modem.init(); // Not working

  String modemInfo = modem.getModemName();
  CoreS3.Display.printf("Modem Name: %s\n", modemInfo);
  Serial.print("Modem Name: ");
  Serial.println(modemInfo);
}

felmue

Hello @markpro

GPIO13 in M5CoreS3 is already used by the speaker amp. So it probably can't be used for serial. See schematic here.

BTW: you don't need to set GPIO2 as output and set it to LOW as GPIO2 is not connected / used by the COM.NB-IoT module. See schematic here.

Thanks
Felix

markpro

@felmue Thanks, after reviewing the docs I also made a mistake in the Pins. Adjusted to below and now I get a reponse of 1 on modem.test(). So looks like I have it connected :)

#define MODEM_TX 7
#define MODEM_RX 1

felmue

Hello @markpro

glad to hear you got it working.

BTW: GPIO1 is already used on port A (I2C). But that is fine as long as you do not need external I2C as well.

Thanks
Felix