Help in gsm programming

Using Arduino Programming Questions
1

I am making a project to take part in the school's science exhibition .the project uses an arduino and gsm module (900)to send a message when motion is detected .I want it to some the message only once
I have written the following code -:

#define SEN_input 10
#define LED_alert 12

void setup()
{
Serial.begin(9600);  
 pinMode(SEN_input, INPUT);
  pinMode(LED_alert, OUTPUT);
Serial.println('AT+CMGF=1'); 
delay(200);
}
void loop()
{
  int thief;
  while(1)
  {
   thief=digitalRead(SEN_input);
   if(thief)
{
digitalWrite(LED_alert,HIGH);
Serial.print('AT+CMGS=\'');
Serial.print("ATD123;");
Serial.println("\"");
Serial.print("manansh!");  
delay(1000);
Serial.write(0x1A);  
Serial.write(0x0D);  
Serial.write(0x0A);  
delay(10000);
   }
   else
   {
     digitalWrite(LED_alert,LOW);
     delay(100);

}
}
}
[code\]
any help will be appreciated, :)  thank you  :)
2

Firstly I'd suggest you put your code inside code tags (simply put

 [code] in front of it and [/code] at the end of it.)

Next I'd suggest you run it and see what happens.
3

KenF first of all thanks your help ,I have uploaded the above code in my arduino but whenever i connect a jumper in pin10, pin12 goes high irrespective of the sensor input

4

What are you using to detect motion? Could you perhaps post a schematic.

5

I am using an ir sensor here is the schematic attached

project.png
project.png1111×442 4.56 KB

6

"infra red sensor" is quite vague. Do you have a link for the actual device. (better still a datasheet but a link would be a good start)

7

Serial.println('AT+CMGF=1');

The ' simbol is just for representing a single caracter not a full string!

   thief=digitalRead(SEN_input);
   if(thief)

Are you debouncing the signal from your sensor?

if(thief)
{
digitalWrite(LED_alert,HIGH);
Serial.print('AT+CMGS='');
Serial.print("ATD9871180166;");

Ok if you have movement then you send the message but why are you using the ATD comand?
ATD is for dial a number...
The rigth sintax to send an SMS is:

Serial.println("AT + CMGS = \"9871180166\"");
  delay(100);
  Serial.println("A test message!");//the content of the message
  delay(100);
  Serial.println((char)26);//the ASCII code of the ctrl+z is 26
  delay(100);
  Serial.println();
8

thank you hugopt, is this right

Run it on your device and it will give you the answer :slight_smile:
Note some SIM900 boards have a small switch to start the modem.If this is your case you will need to press it during boot of just use a pin to do that on your setup() function