SIM900 stopped working

Hardware Arduino GSM Shield
1

Hi, I was using the SIM900 shield to send an SMS, everything worked perfect. When I tried it again at 15 minutes it did not work anymore.

#include <SoftwareSerial.h>
SoftwareSerial SIM900(7, 8);

void setup() {
  SIM900.begin(19200);
  delay(25000);
  Serial.begin(19200);
  Serial.println("Conectado");
}

void loop() {
  sendSMS();
  delay(100);
  SIM900.println();
  delay(30000);
  while(1);
}

void sendSMS() {
  SIM900.print("AT+CMGF=1\r");
  delay(100);
  SIM900.println("AT+CMGS=\"xxxxxxxxxxxx\"");
  delay(100);
  SIM900.println("Mensaje enviado desde Arduino con GSM/GPRS Shield SIM900");
  delay(100);
  SIM900.println((char)26);
  delay(100);
  SIM900.println();
  delay(5000);
  Serial.println("Mensaje enviado con exito!");
}
2

Two suggestions:

  1. Check your connections, make sure none have come loose.
  2. Try running SoftwareSerial at 9600.