RGB Module¶

Introduction¶

The RGB Full Color LED module emits a range of colors by mixing red, green, and blue light. Each color is adjusted by using PWM.It can be used to create colorful lighting effects or to learn how to use PWM (pulse-width modulation) with Arduino.

Principle¶

The RGB MODULE works by using a full-color LED that uses R, G, and B pins with adjustable PWM voltage input. Colors from the LED can be combined. For example, mix blue light and green light give cyan light, red light and green light give yellow light. This is called “The additive method of color mixing”.

Additive color - Wikipedia

Based on this method, we can use the three primary colors to mix the visible light of any color according to different proportions. For example, orange can be produced by more red and less green. The strength of the primary colors (red, blue, green) is adjusted in order to achieve full color mixing effect.PWM is a technique where the duty cycle of a digital signal is modified, adjusting the percentage of time that the signal remains active within a given period. By changing the duty cycle, we can make the LED appear brighter or dimmer.

Usage¶

Hardware components

Arduino Uno R4 or R3 board * 1
RGB Module * 1
Jumper Wires

Circuit Assembly

Code¶

Code explanation¶

The first segment of the code declares and initializes the pins to which each color channel of the RGB LED module is connected.

const int rledPin = 9;  // pin connected to the red color channel
const int gledPin = 10;   // pin connected to the green color channel
const int bledPin = 11;  // pin connected to the blue color channel

The setup() function initializes these pins as OUTPUT. This means we are sending signals OUT from these pins to the RGB LED module.
```
void setup() {
  pinMode(rledPin, OUTPUT);
  pinMode(gledPin, OUTPUT);
  pinMode(bledPin, OUTPUT);
}
```
In the loop() function, the setColor() function is called with different parameters to display different colors. The delay() function is used after setting each color to pause for 1000 milliseconds (or 1 second) before moving on to the next color.
```
void loop() {
  setColor(255, 0, 0);  // Set RGB LED color to red
  delay(1000);
  setColor(0, 255, 0);  // Set RGB LED color to green
  delay(1000);
  // The rest of the color sequence...
}
```
The setColor() function uses the analogWrite() function to adjust the brightness of each color channel on the RGB LED module. The analogWrite() function employs Pulse Width Modulation (PWM) to simulate varying voltage outputs. By controlling the PWM duty cycle (the percentage of time a signal is HIGH within a fixed period), the brightness of each color channel can be controlled, allowing the mixing of various colors.
```
void setColor(int R, int G, int B) {
  analogWrite(rledPin, R);  // Use PWM to control the brightness of the red color channel
  analogWrite(gledPin, G);  // Use PWM to control the brightness of the green color channel
  analogWrite(bledPin, B);  // Use PWM to control the brightness of the blue color channel
}
```

Additional Ideas¶

Try displaying other colors
Integrate the RGB LED with sensors, and display different colors based on the sensor’s value.