We made a major breakthrough today. We got the GSM shield working. Initially, we were concerned as we had heard that the GSM shield could draw up to 2A of current. This would not do an Arduino much good, so it seemed to be a bit of a risk.
We connected the Arduino to the USB on a computer and used a GSM example to send a text...
/*
SMS sender
This sketch, for the Arduino GSM shield,sends an SMS message
you enter in the serial monitor. Connect your Arduino with the
GSM shield and SIM card, open the serial monitor, and wait for
the "READY" message to appear in the monitor. Next, type a
message to send and press "return". Make sure the serial
monitor is set to send a newline when you press return.
Circuit:
* GSM shield
* SIM card that can send SMS
created 25 Feb 2012
by Tom Igoe
This example is in the public domain.
http://arduino.cc/en/Tutorial/GSMExamplesSendSMS
*/
// Include the GSM library
#include <GSM.h>
#define PINNUMBER ""
// initialize the library instance
GSM gsmAccess;
GSM_SMS sms;
void setup()
{
// initialize serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
Serial.println("SMS Messages Sender");
// connection state
boolean notConnected = true;
// Start GSM shield
// If your SIM has PIN, pass it as a parameter of begin() in quotes
while(notConnected)
{
if(gsmAccess.begin(PINNUMBER)==GSM_READY)
notConnected = false;
else
{
Serial.println("Not connected");
delay(1000);
}
}
Serial.println("GSM initialized");
}
void loop()
{
Serial.print("Enter a mobile number: ");
char remoteNum[20]; // telephone number to send sms
readSerial(remoteNum);
Serial.println(remoteNum);
// sms text
Serial.print("Now, enter SMS content: ");
char txtMsg[200];
readSerial(txtMsg);
Serial.println("SENDING");
Serial.println();
Serial.println("Message:");
Serial.println(txtMsg);
// send the message
sms.beginSMS(remoteNum);
sms.print(txtMsg);
sms.endSMS();
Serial.println("\nCOMPLETE!\n");
}
/*
Read input serial
*/
int readSerial(char result[])
{
int i = 0;
while(1)
{
while (Serial.available() > 0)
{
char inChar = Serial.read();
if (inChar == '\n')
{
result[i] = '\0';
Serial.flush();
return 0;
}
if(inChar!='\r')
{
result[i] = inChar;
i++;
}
}
}
}
We found that there was an issue with the serial print in the script. When the serial monitor was "Asking" for a number and we typed it in, the script didn't work. When Brodie rewrote the script to include a stated number it sent a text message. In fact it continued to send messages...
Ten of them in a minute. This of course isn't a problem as the script is simply doing what it is told to do.
Next stage back to getting the dot matrix LED screen to display through the serial monitor...
The GSM needs it's metadata removing too - we don't want that to be displayed.