Arduino Motion Detector

This is an Arduino-based Motion Detector I created. Upon pressing the button, it will arm 10 seconds later. Then beep and blink the LEDs when motion is detected. It can be disarmed by pressing the same button. The code is as follows:

 

/*****

* By Pete Lamonica

* Released under a Creative Commons Non-Commerical/Attribution/Share-Alike

* license

* creativecommons.org/licenses/by-nc-sa/2.0/

****/

#define MOTION_PIN 0

#define SPEAKER_PIN 9

#define RED_LED_PIN 2

#define GREEN_LED_PIN 3

#define ARM_PIN 4

 

#define SECONDS_TO_ARM 10

 

//defines what "motion" is. There's a pull-up resistor on the

// motion sensor, so "high" is motion, while "low" is no motion.

// I allowed some fuzziness on the "motion"

#define MOTION (analogRead(MOTION_PIN)=1000)

 

//Plays a tone of a given pitch

void playTone(int tone, int duration) {

for (long i = 0; i < duration * 1000L; i += tone * 2) {

digitalWrite(SPEAKER_PIN, HIGH);

delayMicroseconds(tone);

digitalWrite(SPEAKER_PIN, LOW);

delayMicroseconds(tone);

}

}

 

//will beep for about 3 seconds and check for disarm in the meantime.

//Could arrange a hardware interrupt to do the same thing

void alarm() {

for(int i=0; i<3; i++) {

if(checkForDisarm()) return;

digitalWrite(RED_LED_PIN, HIGH);

playTone(1432, 300); //F

digitalWrite(RED_LED_PIN, LOW);

digitalWrite(GREEN_LED_PIN, HIGH);

if(checkForDisarm()) return;

playTone(1915, 300); //C

if(checkForDisarm()) return;

digitalWrite(GREEN_LED_PIN, LOW);

delay(400);

if(checkForDisarm()) return;

}

}

 

boolean armed = false; //armed status

 

//arm the device.

void arm() {

armed = true;

 

for(int i=0; i<SECONDS_TO_ARM/2; i++) {

digitalWrite(RED_LED_PIN, LOW);

delay(1000);

if(checkForDisarm()) return;

digitalWrite(RED_LED_PIN, HIGH);

delay(1000);

if(checkForDisarm()) return;

}

}

 

//Check if the system should be disarmed and do so if that's the case.

boolean checkForDisarm() {

if(digitalRead(ARM_PIN) == HIGH && armed) {

armed = false;

digitalWrite(GREEN_LED_PIN, LOW);

digitalWrite(RED_LED_PIN, HIGH);

delay(1000);

return true;

}

return false;

}

 

void setup() {

pinMode(SPEAKER_PIN, OUTPUT);

pinMode(RED_LED_PIN, OUTPUT);

pinMode(GREEN_LED_PIN, OUTPUT);

 

pinMode(ARM_PIN, INPUT);

 

digitalWrite(RED_LED_PIN, LOW);

digitalWrite(GREEN_LED_PIN, LOW);

}

 

int detected = 0;

 

void loop() {

if(MOTION && armed) { //If there's motion and it's armed, sound the alarm

alarm();

delay(1000);

} else if(armed) { //if it's armed, but there's no motion, show a green LED

digitalWrite(RED_LED_PIN, LOW);

digitalWrite(GREEN_LED_PIN, HIGH);

} else { //if it's not armed, show a red LED

digitalWrite(GREEN_LED_PIN, LOW);

digitalWrite(RED_LED_PIN, HIGH);

}

 

//check to see if the "ARM" button has been pressed

if(digitalRead(ARM_PIN) == HIGH && !armed) {

arm();

}

 

//check for a disarm

checkForDisarm();

}

Done