Hello!
I have this GSM/GPRS plugged into my Arduino Mega:
http://www.geeetech.com/wiki/index.php/Arduino_GPRS_Shield
Though it is technically made for the Uno, it is still working on the Mega. Pins D7 and D8 are used for communication, as the board specifies.
Here is my problem. I can perfectly send AT commands to the module. The module can easily dial numbers, and call them. However, when I call the module, it says nothing. Absolutely nothing. I think that the module is supposed to say "RING" on the Serial Monitor when you call it, but there is no response!
Through the audio output, I hear the built-in ringtone, yet there is no feedback from the Serial Monitor!!!
A long while back, I plugged the shield into an Arduino Uno. When I called the module, it worked fine! How come it worked OK on the Uno but not on the Mega??? Here is the code I used on the Uno to get it working last time:
#include <SoftwareSerial.h>
SoftwareSerial SIM900(7, 8); // configure software serial port
void SIM900power()
// software equivalent of pressing the GSM shield "power" button
{
pinMode(9, OUTPUT);
digitalWrite(9, LOW);
delay(1000);
digitalWrite(9, HIGH);
delay(2000);
digitalWrite(9, LOW);
delay(3000);
}
void setup() {
SIM900power();
SIM900.begin(19200); // make sure your GSM is set up at 19200 and not 9600
Serial.begin(115200); // no need to go slow, set your console to 115200
Serial.println("<System ready>\n");
}
void loop() {
int c;
while (SIM900.available()) {
// we have pending communication, read what's coming
c = SIM900.read(); // returns -1 if error
if (c != -1) { // if this is not an error print what we've got
if (c == '\n') Serial.println("[LF]"); // code 0x0A
else if (c == '\r') Serial.println("[CR]"); // code 0x0D
else Serial.print(c); // normal character
}
}
}
BTW, as you can see I am not using any GSM libraries here. Is there any good GSM library that would make this easier?
Thanks in advance!
-SQ