RGB LED With Arduino Uno R3 : 7 Steps

Previously we've used the PWM technology to control an LED brighten and dim. In this lesson, we will use it to control an RGB LED to flash various kinds of color. When different PWM values are set to the R, G, and B pins of the LED, its brightness will be different. When the three different colors are mixed, we can see that the RGB LED flashes different colors.

Step 1: Components

- Arduino Uno board * 1

- USB cable * 1

- Resistor (220Ω) * 1

- RGB LED * 3

- Breadboard * 1

- Jumper wires

Step 2: Principle

RGB LED means red, blue and green LEDs. RGB LED can

emit different colors by mixing the 3 basic colors red, green and blue. So it actually consists of 3 separate LEDs red, green and blue packed in a single case. That’s why it has 4 leads, one lead for each of the 3 colors and one common cathode or anode depending of the RGB LED type. In this tutorial I will be using a common cathode one.

Step 3: The Schematic Diagram

Step 4: Procedures

In this experiment, we will also use PWM which, if you’ve followed the lessons thus far, you already have a basic understanding of. Here we input a value between 0 and 255 to the three pins of the RGB LED to make it display different colors. After connecting the pins of R, G, and B to a current limiting resistor, connect them to the pin 9, pin 10, and pin 11 respectively. The longest pin (GND) of the LED connects to the GND of the Uno. When the three pins are given different PWM values, the RGB LED will display different colors.

Step 1:

Build the circuit.

Step 2:

Download the code from https://github.com/primerobotics/Arduino

Step 3:

Upload the sketch to the Arduino Uno board

Click the Upload icon to upload the code to the control board.

If "Done uploading" appears at the bottom of the window, it means the sketch has been successfully uploaded.

Here you should see the RGB LED flash circularly red, green, and blue first, then red, orange, yellow, green, blue, indigo, and purple.

Step 5: Code

//RGB
LED
//The
RGB LED will appear red, green, and blue first, then red, orange, yellow,
green, blue, indigo, and purple.
//Email:info@primerobotics.in
//Website:www.primerobotics.in
/*************************************************************************/
const
int redPin = 11;  // R petal on RGB LED
module connected to digital pin 11 
const
int greenPin = 10;  // G petal on RGB LED
module connected to digital pin 10 
const
int bluePin = 9;  // B petal on RGB LED
module connected to digital pin 9 
/**************************************************************************/
void
setup()
{
  pinMode(redPin, OUTPUT); // sets the redPin
to be an output 
  pinMode(greenPin, OUTPUT); // sets the
greenPin to be an output 
  pinMode(bluePin, OUTPUT); // sets the bluePin
to be an output 
}    
/***************************************************************************/
void
loop()  // run over and over again  
{    
  // Basic colors:  
  color(255, 0, 0); // turn the RGB LED red 
  delay(1000); // delay for 1 second  
  color(0,255, 0); // turn the RGB LED
green  
  delay(1000); // delay for 1 second  
  color(0, 0, 255); // turn the RGB LED
blue  
  delay(1000); // delay for 1 second 
  // Example blended colors:  
  color(255,0,252); // turn the RGB LED
red  
  delay(1000); // delay for 1 second  
  color(237,109,0); // turn the RGB LED
orange  
  delay(1000); // delay for 1 second  
  color(255,215,0); // turn the RGB LED
yellow  
  delay(1000); // delay for 1 second  
  color(34,139,34); // turn the RGB LED
green  
  delay(1000); // delay for 1 second 
  color(0,112,255); // turn the RGB LED blue  
  delay(1000); // delay for 1 second
  color(0,46,90); // turn the RGB LED  indigo 
  delay(1000); // delay for 1 second
  color(128,0,128); // turn the RGB LED
purple  
  delay(1000); // delay for 1 second
}     
/******************************************************/
void
color (unsigned char red, unsigned char green, unsigned char blue)// the color
generating function  
{    
  analogWrite(redPin, red);   
  analogWrite(greenPin, green); 
  analogWrite(bluePin, blue); 
}
/******************************************************/