SIM800L blinking continously

Projects General Guidance
1

Hi Everyone,

I've followed the this tutorial to connect the SIM800L Module to Arduino. It works fine for some weeks but then it is not working as before. I think that it cannot connect to the network since the LED is blinking 7 or 8 times every 3 second. I am sure about the power supply, connections, antenna. I use the following code:

#include <SoftwareSerial.h>

//Create software serial object to communicate with SIM800L
SoftwareSerial gsm(11, 10); //SIM800L Tx & Rx is connected to Arduino #3 & #2

void setup()
{
  //Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
  Serial.begin(9600);
  
  //Begin serial communication with Arduino and SIM800L
  gsm.begin(9600);

  Serial.println("Initializing..."); 
  delay(1000);

  gsm.println("AT"); //Once the handshake test is successful, i t will back to OK
  updateSerial();
  
}

void loop()
{
    updateSerial();
}

void updateSerial()
{
  delay(500);
  while (Serial.available()) 
  {
    gsm.write(Serial.read());//Forward what Serial received to Software Serial Port
  }
  while(gsm.available()) 
  {
    Serial.write(gsm.read());//Forward what Software Serial received to Serial Port
  }
}

When I the "AT" command it returns the following.

AT
OK

+CPIN: READY

Call Ready

SMS Ready

Any help is appreciated.
Mahdiyar.

2

any suggestion.