Connecting LDR (PhotoResistor) with Arduino

LDR is a resistor which works because of light. Remember that LDR is an analog device.

Mar 13, 2021

•

6520 views

•

0 respects

Components and supplies

LDR, 5 Mohm

Male to male wires

Arduino UNO

5 mm LED: Red

Resistor 220 ohm

Resistor 10k ohm

Tools and machines

Arduino IDE

Project description

Code

Code to see results and to connect LDR with arduino

c_cpp

This is Arduino code. Upload this code and see results!

1int ledPin = 11; // connect LED to digital pin 11
2int ldrPin = A0;  // connect LDR to analog pin A0
3int buzzerPin = 12; // connect buzzer to digital  pin 12
4
5void setup() {
6  pinMode(buzzerPin, OUTPUT);
7  pinMode(ldrPin,  INPUT);       // declare buzzer, LED as INPUT and LDR as OUTPUT
8  pinMode(ledPin,  OUTPUT);
9}
10
11void loop() {
12  int ldrStatus = analogRead(ldrPin); // connect  LDR with Arduino
13
14  if (ldrStatus<=300) { // assign a threshhold value
15    digitalWrite(11, HIGH);
16    tone(buzzerPin, 4000);
17    delay(100);                    //  Condition in which, when the threshhold value is bigger and smaller is the value  coming from LDR
18    digitalWrite(11, LOW);         // then the buzzer will beep  and the LED will blink!
19    noTone(buzzerPin);
20    delay(100);
21  }
22  else {
23    digitalWrite(11, LOW);  // If the value coming from LDR is bigger  and smaller is the threshhold value, then the buzzer will not
24    noTone(buzzerPin);      // beep and the LED will not blink!
25  }
26}

int ledPin = 11; // connect LED to digital pin 11
int ldrPin = A0;  // connect LDR to analog pin A0
int buzzerPin = 12; // connect buzzer to digital  pin 12

void setup() {
  pinMode(buzzerPin, OUTPUT);
  pinMode(ldrPin,  INPUT);       // declare buzzer, LED as INPUT and LDR as OUTPUT
  pinMode(ledPin,  OUTPUT);
}

void loop() {
  int ldrStatus = analogRead(ldrPin); // connect  LDR with Arduino

  if (ldrStatus<=300) { // assign a threshhold value
    digitalWrite(11, HIGH);
    tone(buzzerPin, 4000);
    delay(100);                    //  Condition in which, when the threshhold value is bigger and smaller is the value  coming from LDR
    digitalWrite(11, LOW);         // then the buzzer will beep  and the LED will blink!
    noTone(buzzerPin);
    delay(100);
  }
  else {
    digitalWrite(11, LOW);  // If the value coming from LDR is bigger  and smaller is the threshhold value, then the buzzer will not
    noTone(buzzerPin);      // beep and the LED will not blink!
  }
}

Code to see results and to connect LDR with arduino

c_cpp

This is Arduino code. Upload this code and see results!

1int ledPin = 11; // connect LED to digital pin 11
2int ldrPin = A0;   // connect LDR to analog pin A0
3int buzzerPin = 12; // connect buzzer to digital   pin 12
4
5void setup() {
6  pinMode(buzzerPin, OUTPUT);
7  pinMode(ldrPin,   INPUT);       // declare buzzer, LED as INPUT and LDR as OUTPUT
8  pinMode(ledPin,   OUTPUT);
9}
10
11void loop() {
12  int ldrStatus = analogRead(ldrPin); // connect   LDR with Arduino
13
14  if (ldrStatus<=300) { // assign a threshhold value
15     digitalWrite(11, HIGH);
16    tone(buzzerPin, 4000);
17    delay(100);                    //   Condition in which, when the threshhold value is bigger and smaller is the value   coming from LDR
18    digitalWrite(11, LOW);         // then the buzzer will beep   and the LED will blink!
19    noTone(buzzerPin);
20    delay(100);
21  }
22   else {
23    digitalWrite(11, LOW);  // If the value coming from LDR is bigger   and smaller is the threshhold value, then the buzzer will not
24    noTone(buzzerPin);       // beep and the LED will not blink!
25  }
26}

int ledPin = 11; // connect LED to digital pin 11
int ldrPin = A0;   // connect LDR to analog pin A0
int buzzerPin = 12; // connect buzzer to digital   pin 12

void setup() {
  pinMode(buzzerPin, OUTPUT);
  pinMode(ldrPin,   INPUT);       // declare buzzer, LED as INPUT and LDR as OUTPUT
  pinMode(ledPin,   OUTPUT);
}

void loop() {
  int ldrStatus = analogRead(ldrPin); // connect   LDR with Arduino

  if (ldrStatus<=300) { // assign a threshhold value
     digitalWrite(11, HIGH);
    tone(buzzerPin, 4000);
    delay(100);                    //   Condition in which, when the threshhold value is bigger and smaller is the value   coming from LDR
    digitalWrite(11, LOW);         // then the buzzer will beep   and the LED will blink!
    noTone(buzzerPin);
    delay(100);
  }
   else {
    digitalWrite(11, LOW);  // If the value coming from LDR is bigger   and smaller is the threshhold value, then the buzzer will not
    noTone(buzzerPin);       // beep and the LED will not blink!
  }
}

Downloadable files

LDR with Arduino UNO connection

Connect LDR with arduino with this diagram and also connect a LED with 220Ω to Arduino digital pin number '11' and you can connect buzzer also!

LDR with Arduino UNO connection

Comments

Only logged in users can leave comments

rudraksh2008

0 Followers

•

0 Projects

Intro

Trademarks & CopyrightsWhistleblowingDigital Services ActTerms of ServicePrivacy PolicySecurityCookie Settings

Report content