Introduction: Light Sensitive Alarm
In this Instructables, you will know how to make a Light sensitive alarm. It will be able to detect different amounts of light and then play a song to your choosing.
Materials needed:
-1 Arduino Uno or any other Arduino
-1 LDR (light dependent resistor).
-1 buzzer or speakers
-1 project box
-breadboard and wires
Step 1: Making the Circuitry
For the circuit connect the buzzer to GND and DP 9
For the LDR connect one side to GND and the other to A0 and add a resistor between the LDR and A0
Step 2: Another View
Step 3: Codeing
Below is the code used to make the alarm run, Ive set it so it plays the melody of Final count down
int rcvpin=A0;
int buzzpin=9;
void setup()
{
pinMode(rcvpin,INPUT);
pinMode(buzzpin,OUTPUT);
buzz(200);
buzz(200);
buzz(200);
delay(2000);
Serial.begin(9600);
}
void loop()
{
int ldrval=analogRead(rcvpin);
Serial.println(ldrval);
if(ldrval<=800)
{
//buzz(50);
playmelody();
}
}
#define C_note 261
#define C_sharp 277
#define D_note 293
#define D_sharp 311
#define E_note 329
#define F_note 349
#define F_sharp 369
#define G_note 391
#define G_sharp 415
#define A_note 440
#define A_sharp 466
#define B_note 246
int melody2[] = { F_sharp, 16, E_note, 16, F_sharp, 64, B_note, 64,
G_note, 16, F_sharp, 16, G_note, 32, F_sharp, 32, E_note, 64,
G_note, 16, F_sharp, 16, G_note, 64, B_note, 64,
E_note, 16, D_note, 16, E_note, 32, D_note, 32,
C_note, 32, E_note, 32, D_note, 64, F_sharp, 16,
E_note, 16, F_sharp, 64, B_note, 64,
0, 0 };
int melody[] = { C_sharp, B_note, C_sharp, F_sharp, D_note, C_sharp, D_note, C_sharp, B_note, D_note,
C_sharp, D_note, F_sharp, B_note, A_note, B_note, A_note, G_sharp, B_note, A_note,
G_sharp, A_note, B_note, A_note, B_note, C_sharp, B_note, A_note, G_sharp, F_note,
D_note, C_sharp, C_sharp, C_sharp, D_note, C_sharp, B_note, C_sharp };
void playmelody() {
int i=0;
while(melody2[i]>0) {
tone(buzzpin, melody2[i]);
delay(melody2[i+1]*10);
i=i+2;
}
noTone(buzzpin);
}
void buzz(unsigned char time)
{
analogWrite(buzzpin,170);
delay(time);
analogWrite(buzzpin,0);
delay(time);
}
Step 4: Fitting the Box
After wiring the breadboard and making sure the code works. move the breadboard on top of the Arduino to maximize space used. After that go ahead and drill out the holes for the LDR and power cord.
Step 5: Finished
After all that is done the LDR and power cord should fit perfectly