Controlling RGB LED with Arduino

Difficulty Level: Beginner

This tutorial will show how to control the color and brightness of an RGB LED using an Arduino. Each color (Red, Green, and Blue) can be independently controlled to create various color combinations.

Components Required

• 1 x Arduino (any model)
• 1 x Common Anode or Common Cathode RGB LED
• 3 x 220Ω Resistors
• Breadboard
• Jumper Wires

Wiring Diagram

Connect the RGB LED to the Arduino as follows:

• Connect the common pin of the RGB LED (longest pin) to 5V (for Common Anode) or GND (for Common Cathode).
• Connect the Red pin of the RGB LED to Arduino digital pin 9 through a 220Ω resistor.
• Connect the Green pin of the RGB LED to Arduino digital pin 10 through a 220Ω resistor.
• Connect the Blue pin of the RGB LED to Arduino digital pin 11 through a 220Ω resistor.

How RGB LEDs Work

RGB LEDs consist of three LEDs (Red, Green, Blue) combined into one package. By adjusting the brightness of each individual LED using PWM, you can create different colors. The Arduino will control the brightness of each color channel using the analogWrite() function, which outputs PWM signals.

Code Explanation

In this code, we use three PWM pins (pins 9, 10, and 11) to control the red, green, and blue components of the RGB LED. By adjusting the PWM values, we can mix different amounts of red, green, and blue to create various colors.

Arduino Code

Here is the Arduino code to control an RGB LED:

int redPin = 9;   // Red LED pin
int greenPin = 10; // Green LED pin
int bluePin = 11;  // Blue LED pin

void setup() {
  // Set the RGB pins as output
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  // Cycle through different colors
  setColor(255, 0, 0);  // Red
  delay(1000);
  setColor(0, 255, 0);  // Green
  delay(1000);
  setColor(0, 0, 255);  // Blue
  delay(1000);
  setColor(255, 255, 0);  // Yellow
  delay(1000);
  setColor(0, 255, 255);  // Cyan
  delay(1000);
  setColor(255, 0, 255);  // Magenta
  delay(1000);
  setColor(255, 255, 255); // White
  delay(1000);
}

// Function to set RGB color
void setColor(int redValue, int greenValue, int blueValue) {
  analogWrite(redPin, redValue);
  analogWrite(greenPin, greenValue);
  analogWrite(bluePin, blueValue);
}
            

Upload and Test

1. Connect your Arduino to the computer and upload the code.
2. Observe the RGB LED cycling through different colors.
3. Adjust the values in the setColor() function to create your own custom colors.

Optional: Potentiometer Control

If you'd like to control the brightness of each color manually, you can add three potentiometers to the circuit and adjust the PWM values based on the potentiometer readings.

// Use 3 potentiometers to control the RGB values
int potRed = A0;
int potGreen = A1;
int potBlue = A2;

void loop() {
  int redValue = analogRead(potRed) / 4;
  int greenValue = analogRead(potGreen) / 4;
  int blueValue = analogRead(potBlue) / 4;

  setColor(redValue, greenValue, blueValue);
  delay(10);
}
            

Conclusion

By controlling the individual colors of an RGB LED, you can create a wide range of colors and even dynamic lighting effects. This project is an excellent way to understand how PWM and color mixing work.