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!");
}