Hello. I am new to Arduino, but very excited to be using it. It has been very simple in all other aspects until I tried to use the interrupts. I have a PIR motion sensor (http://www.robotshop.com/productinfo.aspx?pc=RB-See-194&lang=en-US) attached to the arduino mega 2560 ADK R3 board (http://arduino.cc/en/uploads/Main/ArduinoADKFront.jpg). I have connected the motion sense pin of the sensor to pin 18 (interrupt 5) of the board. Have confirmed the pin out and I have confirmed that the pin does in fact go high for about 3 seconds when motion is detected. I have confirmed this with a volt meter and I have connected the pin to the analog A1 input to read the voltage. So it is fully functioning. However when I connect it to pin 18 and set up the pin for the interrupt I cannot get it to detect the rising edge of the motion sense pin and call the ISR. I have tried to move the pin to interrupt 0 and interrupt 1. I cannot use these pins in my design because I intend to use those ports for communication with other devices. The following is my code that I am trying to use.
Can anyone give me an idea of what I am doing wrong?
/**********
Motion Sensor Code
***********/
int motionPin = 18;
volatile int motionSensorState = LOW;
void setup(){
// Open serial 0 communications and wait for port to open:
//Serial port 0 will be used to send debugger messages to the PC
//that is connected via the USB port.
Serial.begin(57600);
pinMode(motionPin, INPUT);
attachInterrupt(5, pin5isr, RISING);
Serial.println("Motion Sensor Pin configured");
}
void loop() {
if(motionSensorState){
Serial.println("Motion Detected");
motionSensorState = LOW;
}
}
void pin5isr()
{
motionSensorState = HIGH;
}