ARDUINO MEGA 2560 gsm module 900a mini v3.8.2 can't establish network

Official Hardware Retired GSM Shield
1

I'm new to arduino coding and we are tasked with making a smoke sensor that sends a sms message to a user when it detects smoke. One problem that we've encountered is that our gsm module 900a can't seem to find a network (the status LED blinks every second rather than every 3 seconds). How can we fix this problem?

I will provide the code below

2 
int buzzer = 8;
int smokeA0 = A5;
int sensorThres = 0; 

#include<SoftwareSerial.h>

SoftwareSerial GSM (9, 10);

void setup() 
{
  pinMode(buzzer, OUTPUT);
  pinMode(smokeA0, INPUT);
  Serial.begin(9600);
  GSM.begin (9600);
  delay(100);
}

void loop() {
  int analogSensor = analogRead(smokeA0);
  
  if (analogSensor > sensorThres) 
  {
     digitalWrite(buzzer, HIGH);
     delay (1000);
     Serial.println("AT+CMGF=1");    
     delay(1000);  
     Serial.println("AT+CMGS=\"+639053188487\"\r"); 
     Serial.println("smoke detected alert");
     Serial.println((char)26);
     delay(100);

  }
  else
  {
    digitalWrite(buzzer,LOW);
  }
  delay(50);
}

type or paste code here

3

Hi,

The SIM900A seems to be limited to Asia, and only compatible with 2G.

Have you check this limitations ?

4

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