Description: A Light Dependent Resistor (LDR) Sensor is used to detect and show changes in light levels with an LED light meter
Arduino Code:
const int ldrPin = A0;
const int ledPin1 = 10;
const int ledPin2 = 9;
const int ledPin3 = 8;
const int ledPin4 = 7;
const int ledPin5 = 6;
const int ledPin6 = 5;
const int ledPin7 = 4;
const int ledPin8 = 3;
const int ledPin9 = 2;
int ldrValue = 0;
int ldrlevel1 = 200;
int ldrlevel2 = 220;
int ldrlevel3 = 250;
int ldrlevel4 = 270;
int ldrlevel5 = 300;
int ldrlevel6 = 320;
int ldrlevel7 = 350;
int ldrlevel8 = 370;
int ldrlevel9 = 400;
void setup() {
Serial.begin(9600);
pinMode(ledPin1, OUTPUT);
pinMode(ledPin2, OUTPUT);
pinMode(ledPin3, OUTPUT);
pinMode(ledPin4, OUTPUT);
pinMode(ledPin5, OUTPUT);
pinMode(ledPin6, OUTPUT);
pinMode(ledPin7, OUTPUT);
pinMode(ledPin8, OUTPUT);
pinMode(ledPin9, OUTPUT);
}
void loop() {
ldrValue = analogRead(ldrPin);
Serial.println(ldrValue);
if (ldrValue < ldrlevel1) {
digitalWrite(ledPin9, HIGH);
}
else if (ldrValue < ldrlevel2) {
digitalWrite(ledPin9, LOW);
digitalWrite(ledPin8, HIGH);
}
else if (ldrValue < ldrlevel3) {
digitalWrite(ledPin8, LOW);
digitalWrite(ledPin7, HIGH);
}
else if (ldrValue < ldrlevel4) {
digitalWrite(ledPin7, LOW);
digitalWrite(ledPin6, HIGH);
}
else if (ldrValue < ldrlevel5) {
digitalWrite(ledPin6, LOW);
digitalWrite(ledPin5, HIGH);
}
else if (ldrValue < ldrlevel6) {
digitalWrite(ledPin5, LOW);
digitalWrite(ledPin4, HIGH);
}
else if (ldrValue < ldrlevel7) {
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin3, HIGH);
}
else if (ldrValue < ldrlevel8) {
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin2, HIGH);
}
else if (ldrValue < ldrlevel9) {
digitalWrite(ledPin2, LOW);
digitalWrite(ledPin1, HIGH);
}
else {
digitalWrite(ledPin1, LOW);
}
}