CODEWITHSUNDEEP
arduinosmsgsmat-command
Miguel
Miguel

Reputation: 3044

SMS notification not working with Arduino Nano with a GSM module

I want to use an Arduino Nano to monitor SMS traffic of a GSM module. I'm able to read and send SMS but the notification system is not working: when I send an SMS (to the SIM card that is in the GSM module) no new data becomes available in the Serial port. Any idea why or how can I debug to find the problem?

The communication is done through pins 9 and 10 of Arduino and RX and TX for the GSM module, which is an Quectel EC25. The code I'm using:

#include <SoftwareSerial.h>

#define DEBUG Serial
SoftwareSerial EC25(10,9); // RX, TX - 9600 baud rate
// pin 8 of raspi -> pin 9 of arduino nano 
// pin 10 of raspi -> pin 10 of arduino nano

#define AT_RESPONSE_LEN 100
#define TIMEOUT 1000

void setup() {
  // put your setup code here, to run once:
  EC25.begin(9600);
  DEBUG.begin(9600);

  // some AT commands just to see if the coms are ok
  sendATComm("AT","OK\r\n");
  sendATComm("AT+IPR?","OK\r\n");
  sendATComm("AT+CGSN","OK\r\n");

  sendATComm("AT+CNMI=2,1,0,0,0","OK\r\n");

  DEBUG.println("listennig");
}

void loop() {
  // put your main code here, to run repeatedly:

  if (EC25.available()){
    DEBUG.println("Notification received!");
  }

}



// function for sending at command.
const char* sendATComm(const char *command, const char *desired_reponse)
{
  uint32_t timer;
  char response[AT_RESPONSE_LEN]; // module response for AT commands.

  memset(response, 0 , AT_RESPONSE_LEN);
  EC25.flush();

  sendATCommOnce(command);

  timer = millis();
   while(true){
    if(millis()-timer > TIMEOUT){
      sendATCommOnce(command);
      timer = millis();
    }
    char c;
    int i = 0;

    while(EC25.available()){
      c = EC25.read();
      DEBUG.write(c);
      response[i++]=c;
      delay(2);
      }
      if(strstr(response, desired_reponse)){
        return response;
        memset(response, 0 , strlen(response));
        break;
      }
  }
}

// send at comamand to module
void sendATCommOnce(const char *comm)
{
  EC25.print(comm);
  EC25.print("\r");
  delay(100);
}

Upvotes: 0

Views: 512

Answers (1)

Miguel
Miguel

Reputation: 3044

So, it turns out that I had to define the output port of URC to use UART communication (not using it as default).

The default configuration was set to either usbat or usbmodem, meaning that the notification information I was waiting for was being sent to one of these serial ports. But I was listening to UART (through RX and TX pints) and therefore I was not getting any notification.

AT command QURCCFG can be used to set which port URC signals should be sent to. In this case I want them to be sent to UART:

AT+QURCCFG="urcport","uart1"

Upvotes: 1

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