Introduction: Arduino Photoresistor LED On/off

this is another simple arduino project that turn on light when it's dark and turn off when is light))

Step 1: Materials

You will need:

Arduino

Breadboard

2x 240ohm resistors

1x Clear White l.e.d

1x photoresistor

Some Jumper Cables

Step 2: Circuite

Step 3: The Code

//photoresistor A Style Tech.

int Pr = 0; // will be used for analog 0.

int PrValue = 0; // value of output

int Pr_Input = 19; // value of when light is on

void setup() {

Serial.begin(9600); //start serial Monitor

pinMode(8, OUTPUT); // pin 8 as output

}

void loop() {

PrValue = analogRead(Pr);

Serial.println(PrValue); //prints photoresistor value

delay(100); // value updated every 0.1 second.

if (PrValue < Pr_Input) // if sensor value is less than 19, light will turn on.

{ digitalWrite(8, HIGH);//LED on } else { digitalWrite(8, LOW);// LED off }

}

Step 4: Finish!!

if all went well, try to add more leds

and change sensitivity of photoresistor " int Pr_Input = 19; // value of when light is on"

GOOD LUCK! ;)

Comments

author
RăzvanN4 (author)2017-06-27

Can i make the same project (photoresistor-LED-on/off) combined with a speedometer, using the same arduino board and the same breadboard?

author
HarDizzeR (author)2017-06-07

Can I use 12v led strips ?

author
thunderjew made it! (author)2017-02-17

This is a very nice and simple project. I built it onto a PCB, and used terminals for the LED and for the photo resistor, so that I can change them or extend the wires without having to solder anything

vlcsnap-2017-02-17-19h58m22s191.jpgvlcsnap-2017-02-17-19h58m28s440.jpg
author
WillA2 made it! (author)2016-10-17

Made it.... I am currently testing how how many/what type of LED will work on this setup. I would like to see if I can get something like the LED light bars but only a 4 LED pod to work on something like this. But thanks for the easy write up and how to..

20161017_142046_HDR.jpg
author
Lionbait (author)2016-02-23

Any one else getting this message, when trying to load the code

Arduino: 1.6.5 (Windows 8.1), Board: "Arduino Uno"

sketch_feb23a.ino: In function 'void loop()':
sketch_feb23a:37: error: expected '}' at end of input
expected '}' at end of input

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.

author
PaigeK8 (author)Lionbait2016-05-13

int Pr = 0; // will be used for analog 0.

int PrValue = 0; // value of output

int Pr_Input = 19; // value of when light is on

void setup() {

Serial.begin(9600); //start serial Monitor

pinMode(8, OUTPUT); // pin 8 as output

}

void loop() {

PrValue = analogRead(Pr);

Serial.println(PrValue); //prints photoresistor value

delay(100); // value updated every 0.1 second.

if (PrValue < Pr_Input) {

digitalWrite(8, HIGH);

} else {

digitalWrite(8, LOW); }

}

author
PaigeK8 (author)2016-05-13

USE THIS

int Pr = 0; // will be used for analog 0.

int PrValue = 0; // value of output

int Pr_Input = 19; // value of when light is on

void setup() {

Serial.begin(9600); //start serial Monitor

pinMode(8, OUTPUT); // pin 8 as output

}

void loop() {

PrValue = analogRead(Pr);

Serial.println(PrValue); //prints photoresistor value

delay(100); // value updated every 0.1 second.

if (PrValue < Pr_Input) {

digitalWrite(8, HIGH);

} else {

digitalWrite(8, LOW); }

}

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