# Arduino Alarm2

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In this project you will build an alarm that goes off when someone walks by. You can also arm and disarm the alarm using your iOS iPhone. This project can be helpful to you whether you really want to set up an alarm or if you simply want to brush up on your coding skills. Either way, I hope you find this interesting and please leave feedback if you liked it.

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## Step 1: Materials

For this project you will need:

1) An Arduino,

3) A few wires

4) An hc-sr04 ultrasonic sensor,

5) A piezo speaker.

6) HM-10 bluetooth micro-controller

## Step 2: Assemble the Alarm

First: For the ultrasonic sensor, using wires, put ground into ground, Echo into D7, Trig into D8, and Vcc into 5v.

How it works- It emits an ultrasound at 40 000 Hz which travels through the air and if there is an object or obstacle on its path It will bounce back to the module. Considering the travel time and the speed of the sound you can calculate the distance. In order to generate the ultrasound you need to set the Trig on a High State for 10 µs. That will send out an 8 cycle sonic burst which will travel at the speed sound and it will be received in the Echo pin. The Echo pin will output the time in microseconds the sound wave traveled. For example, if the object is 10 cm away from the sensor, and the speed of the sound is 340 m/s or 0.034 cm/µs the sound wave will need to travel about 294 u seconds. But what you will get from the Echo pin will be double that number because the sound wave needs to travel forward and bounce backward. So in order to get the distance in cm we need to multiply the received travel time value from the echo pin by 0.034 and divide it by 2.

Second: Connect the bluetooth module to the Arduino. Vcc to 5v, GND to ground, TXD to D10, RXD to D11.

Third: connect the speaker to the Arduino. Connect one pin to D9 and one to GND.

## Step 3: Input the Code

#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 166

1 #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()

{ pinMode (9, OUTPUT);

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; if (distance = 3 )

{ Serial.println(distance);

tone(9, NOTE_C8);

delay(30);

tone(9,NOTE_D7);

delay(20); } //Delay 50ms before next reading. delay(50); }

If you want to test the blynk

#include

#define BLYNK_PRINT Serial #include #include char auth[ ] = "332d606ac1934167af47d89634cb57bf"; SoftwareSerial SerialBLE(10,11); void setup() { // put your setup code here, to run once: Serial.begin(9600); SerialBLE.begin(9600); Blynk.begin(SerialBLE, auth); Serial.println(" Waiting for connections");

}

void loop() { // put your main code here, to run repeatedly: Blynk.run(); }

#define BLYNK_PRINT Serial #include #include char auth[ ] = "332d606ac1934167af47d89634cb57bf"; SoftwareSerial SerialBLE(10,11); void setup() { // put your setup code here, to run once: Serial.begin(9600); SerialBLE.begin(9600); Blynk.begin(SerialBLE, auth); Serial.println(" Waiting for connections");

}

void loop() { // put your main code here, to run repeatedly: Blynk.run(); }

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