Introduction: How to Make Secret Drawer Alarm

About: I am a student and a electronic enthusiast. I just started instructables and need your support.

This alarm can be put in your drawer Which you don't Wan't anyone to peek into. This project can be done with the Arduino laying around and some stuff that you can get for dirt cheap in from the electronics store.

I first thought of using an LDR for this but it could not work because what if someone opened your drawer and there was no light in the room.

I put this above my keyboard so if anyone pulled my keyboard out it will turn on the alarm.

And Don't forget to Vote for me.

Step 1: Gather Parts

  • Arduino
  • IR Emitter
  • Photodiode
  • Buzzer
  • Breadboard
  • 3k ohms resistor
  • 150 ohms resitor

gather these things

Step 2: Assemble


  • Ard 5v => 150 ohms => IR Emitter Anode
  • Ard GND => IR Emitter Cathode
  • D2 => 3k Ohms => Photodiode Cathode
  • Ard GND => Photodiode Anode
  • A0 => Photodiode Cathode
  • D13 => Buzzer +
  • Ard GND => Buzzer -

Step 3: Upload the Code

Upload The Code:

int pd=2; //Photodiode to digital pin 2
int buzz=13; //piezo buzzer to digital pin 13 int senRead=0; //Readings from sensor to analog pin 0 int limit=850; //Threshold range of an obstacle void setup() { pinMode(pd,OUTPUT); pinMode(buzz,OUTPUT); digitalWrite(pd,HIGH); //supply 5 volts to photodiode digitalWrite(buzz,LOW); //set the buzzer in off mode (initial condition) Serial.begin(9600); //setting serial monitor at a default baund rate of 9600 } void loop() { int val=analogRead(senRead); //variable to store values from the photodiode Serial.println(val); // prints the values from the sensor in serial monitor if(val > limit) //If obstacle is nearer than the Threshold range { tone(buzz,500,100); // Buzzer will be in ON state delay(20); } else if(val <= limit) //If obstacle is not in Threshold range { digitalWrite(buzz,LOW); //Buzzer will be in OFF state delay(20); } }

Step 4: Support

Support Me By Voting And sharing This Instructable.


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