Make A Mood Lamp with Arduino

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1 Summary of Make A Mood Lamp with Arduino

Summary of Make A Mood Lamp with Arduino

This tutorial guides beginners to create a smooth mood lamp using Arduino that changes colors gradually and only activates in a dark environment. The project utilizes an LDR sensor to detect ambient light and PWM control for smooth LED brightness transitions. The lamp features a single RGB LED or separate red, green, and blue LEDs, with color brightness modulated via sine wave functions to achieve seamless color changes as the room darkens.

Parts used in the Smooth Mood Lamp with Arduino:

Arduino
Jumper wires
RGB LED or separate Red, Green, and Blue LEDs
LDR (Light Dependent Resistor)
Protoboard
Sheet of paper

Hi! In this tutorial you will learn to make a mood lamp with Arduino.
I know that you may have seen a lot of mood lamp projects with Arduino, but I wasn’t very satisfied with them because they all change the color very abruptly. So, I decided to make a smooth mood lamp and I also made it to turn on only when the room is dark.
This project is good for those who are beginners in the Arduino’s world.

Step 1: Material

For this instructable you are gonna need:
– Arduino
– Jumper wires
– 1 RGB LED or 1 red LED, 1 green LED and 1 blue LED
– LDR (Light Dependent Resistor)
– Protoboard
– Sheet of paper

Step 2: Time to code!

Write the code above on the Arduino program.
Darker the ambient light is, the higher is the value read from the LDR.
I used PWM to change led’s brightness.

// Smooth RGB mood lamp
// Changes an RGB LED’s color smoothly that only turns on
// when it’s dark around it.
// Author: Ricardo Ouvina
// Date: 19/07/2012
// Version: 2.0
// —————————————————
// The brightness of the leds follows these equations:
// Red = sin(x)
// Green = sin(x + PI/3)
// Blue = sin(x + 2PI/3)
// for x from 0 to PI
// —————————————————

float RGB[3];
int ldrPin = 0;     // LDR in Analog Input 0 to read the ambient light
int ambientLight;   // variable to store the value of the ambient light
int redLed   = 11; // red LED in Digital Pin 11 (PWM)
int greenLed = 10; // green LED in Digital Pin 10 (PWM)
int blueLed = 9;   // blue LED in Digital Pin 9 (PWM)

void setup(){
pinMode(redLed,OUTPUT); // tell arduino it’s an output
pinMode(greenLed,OUTPUT);// tell arduino it’s an output
pinMode(blueLed,OUTPUT); // tell arduino it’s an output

// set all the outputs to low
digitalWrite(redLed,LOW);
digitalWrite(greenLed,LOW);
digitalWrite(blueLed,LOW);
}

void loop(){
for (float x=0;x<PI;x=x+0.00001){
RGB[0]=255*abs(sin(x*(180/PI))); // calculate the brightness for the red led
RGB[1]=255*abs(sin((x+PI/3)*(180/PI))); // calculate the brightness for the green led
RGB[2]=255*abs(sin((x+(2*PI)/3)*(180/PI)));// calculate the brightness for the blue led
ambientLight=analogRead(ldrPin); // read an store the ambient light
if(ambientLight>600){ // start only if the ambient light is very low
// write the brightness on the leds
analogWrite(redLed,RGB[0]);
analogWrite(greenLed,RGB[1]);
analogWrite(blueLed,RGB[2]);
}
else{
digitalWrite(redLed,LOW);
digitalWrite(greenLed,LOW);
digitalWrite(blueLed,LOW);
}
for(int i=0;i<3;i++){
if(RGB[i]<1){
delay(100);
}
if(RGB[i]<5){
delay(50);
}
if(RGB[i]<10){
delay(10);
}
if(RGB[i]<100){
delay(5);
}
}
delay(1);
}
}