Here I am using Arduino uno and GSM sim900A, I want to read sms from sim900A. But i am trying to read message, it is showing the empty values. I tried different methods, but no use. Here I have added my script. Please help me.
#include <avr wdt.h="">
String phoneSMS = "+91xxxxxxxxxx";
String messageTxt;
void setup()
{
Serial.begin(9600);
delay(60000);
srl_msg();
}
String srl_msg()
{
Serial.println("AT+CMGF=1\r");
delay(1000);
Serial.println("AT+CNMI=2,2,0,0,0");
delay(1000);
Serial.println("AT+CMGL=\"ALL\"\r"); // to read ALL the SMS in text mode
delay(1000);
char txtmsg2[100]; // AT command output
String date = readSerial(txtmsg2);
String value = date.substring(1, 50);
messageTxt = "Internal - Heart Beat;";
messageTxt.concat(value);
Serial.println(value);
SendSMS(messageTxt);
}
void loop()
{
}
void SendSMS(String message)
{
Serial.print("at+cmgf=1\r");
delay(1000);
Serial.print("at+cmgs=\"");
Serial.print(phoneSMS);
Serial.println("\"");
delay(1000);
Serial.println(message);
delay(1000);
Serial.print((char)26);
delay(15000); // AAN
}
String readSerial(char result[])
{
int i = 0;
while (Serial.available() > 0)
{
char inChar = Serial.read();
if (inChar != '\r')
{
result[i] = inChar;
i++;
}
}
return result;
}
output is look like this: AT+CMGF=1
OK
AT+CNMI=2,2,0,0,0
OK
AT+CMGL="ALL"
OK
