A motion sensor alarm that triggers when something in front of it moves. I created this so I could tell if someone (my parents) entered my room while I am wearing headphones. I don't hear the sound of the door opening when I have them on, but the alarm is loud enough to alert me. I could also tell if someone entered my room when I'm in a different room because the alarm is loud enough to be heard across the house. I chose the box design for 2 reasons. 1: It's convenient, durable, and easy to use. 2: More importantly it blends in with its surroundings. One wouldn't be able to tell at first glance that it's a motion sensor. This wouldn't be the case if it was a 3d printed design.

Supplies

4 wires
a motion sensor
an Arduino board
a battery pack
batteries for pack (if necessary)
a speaker
Arduino app
The code
A box
Knife or other sharp tool

Step 1:

Gather supplies (listed under "Supplies" section)

Step 2:

Plug in motion sensor (I did j12-j15)

Step 3:

plug in wires

Gnd to Gnd
Echo to 7
Trig to 8
Vcc to 5v

Step 4:

Plug in speaker into 9 and Gnd

Pictures include it by itself and with other wires.

Step 5:

Put batteries in pack if necessary.

Step 6:

Plug battery pack into Arduino.

Step 7:

copy this code into Arduino app:

#define NOTE_B0 31

#define NOTE_C1 33

#define NOTE_CS1 35

#define NOTE_D1 37

#define NOTE_DS1 39

#define NOTE_E1 41

#define NOTE_F1 44

#define NOTE_FS1 46

#define NOTE_G1 49

#define NOTE_GS1 52

#define NOTE_A1 55

#define NOTE_AS1 58

#define NOTE_B1 62

#define NOTE_C2 65

#define NOTE_CS2 69

#define NOTE_D2 73

#define NOTE_DS2 78

#define NOTE_E2 82

#define NOTE_F2 87

#define NOTE_FS2 93

#define NOTE_G2 98

#define NOTE_GS2 104

#define NOTE_A2 110

#define NOTE_AS2 117

#define NOTE_B2 123

#define NOTE_C3 131

#define NOTE_CS3 139

#define NOTE_D3 147

#define NOTE_DS3 156

#define NOTE_E3 165

#define NOTE_F3 175

#define NOTE_FS3 185

#define NOTE_G3 196

#define NOTE_GS3 208

#define NOTE_A3 220

#define NOTE_AS3 233

#define NOTE_B3 247

#define NOTE_C4 262

#define NOTE_CS4 277

#define NOTE_D4 294

#define NOTE_DS4 311

#define NOTE_E4 330

#define NOTE_F4 349

#define NOTE_FS4 370

#define NOTE_G4 392

#define NOTE_GS4 415

#define NOTE_A4 440

#define NOTE_AS4 466

#define NOTE_B4 494

#define NOTE_C5 523

#define NOTE_CS5 554

#define NOTE_D5 587

#define NOTE_DS5 622

#define NOTE_E5 659

#define NOTE_F5 698

#define NOTE_FS5 740

#define NOTE_G5 784

#define NOTE_GS5 831

#define NOTE_A5 880

#define NOTE_AS5 932

#define NOTE_B5 988

#define NOTE_C6 1047

#define NOTE_CS6 1109

#define NOTE_D6 1175

#define NOTE_DS6 1245

#define NOTE_E6 1319

#define NOTE_F6 1397

#define NOTE_FS6 1480

#define NOTE_G6 1568

#define NOTE_GS6 1661

#define NOTE_A6 1760

#define NOTE_AS6 1865

#define NOTE_B6 1976

#define NOTE_C7 2093

#define NOTE_CS7 2217

#define NOTE_D7 2349

#define NOTE_DS7 2489

#define NOTE_E7 2637

#define NOTE_F7 2794

#define NOTE_FS7 2960

#define NOTE_G7 3136

#define NOTE_GS7 3322

#define NOTE_A7 3520

#define NOTE_AS7 3729

#define NOTE_B7 3951

#define NOTE_C8 4186

#define NOTE_CS8 4435

#define NOTE_D8 4699

#define NOTE_DS8 4978

#define echoPin 7 // Echo Pin

#define trigPin 8 // Trigger Pin

#define LEDPin 13 // Onboard LED

int maximumRange = 200; // Maximum range needed

int minimumRange = 0; // Minimum range needed

long duration, distance; // Duration used to calculate distance

void setup() {

Serial.begin(9600);

pinMode (9, OUTPUT); //speaker

Serial.begin (9600);

pinMode(trigPin, OUTPUT);

pinMode(echoPin, INPUT);

pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)

}

void loop() {

/* The following trigPin/echoPin cycle is used to determine the

distance of the nearest object by bouncing soundwaves off of it. */

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

//Calculate the distance (in cm) based on the speed of sound.

distance = duration/58.2;

//Serial.write(distance);

if (distance < 80 ){

Serial.println(distance);

tone(9, NOTE_C8);

delay(5);

tone(9,NOTE_D7);

delay(20);

}

else {

noTone(9);

}

//Delay 50ms before next reading.

delay(500);

}

Step 8:

Plug in Arduino and send code to it.

(Image shows device being plugged in.)

Step 9:

Cut hole in box (in proper location) so motion sensor sense motion.

Step 10:

Place device in box. Make sure motion sensor is aligned with the hole.

Step 11:

Put in desired location.

(Image shows device being placed in doorway)

Introduction: Motion Sensor Alarm