Chapter 5 RGB LED

In this chapter, we will learn how to control a RGB LED. It can emit different colors of light. Next, we will use RGB LED to make a multicolored light.

Project 5.1 Random Color Light

In this project, we will make a multicolored LED. And we can control RGB LED to switch different colors automatically.

Component List

ESP32-S3-WROOM x1
GPIO Extension Board x1
830 Tie-Points Breadboard x1
LED-RGB x1
Resistor 220Ω x3
Jumper Wire x4

Component knowledge

RGB-LED 

Connect

Sketch

Upload following sketch: LAFVIN_Super_Starter_Kit_For_Esp32_S3\Sketches\05.1_RandomColorLight

We need to create three PWM channels and use random duty cycle to make random RGB LED color.

Sketch_05.1_ColorfulLight

With the code downloaded to ESP32-S3 WROOM, RGB LED begins to display random colors.

Code

The following is the program code:

const byte ledPins[] = {38, 39, 40};    //define red, green, blue led pins
const byte chns[] = {0, 1, 2};          //define the pwm channels
int red, green, blue;
void setup() {
for (int i = 0; i < 3; i++) {   //setup the pwm channels,1KHz,8bit
    ledcAttachChannel(ledPins[i], 1000, 8, chns[i]);
}
}

void loop() {
red = random(0, 256);
green = random(0, 256);
blue = random(0, 256);
setColor(red, green, blue);
delay(200);
}

void setColor(byte r, byte g, byte b) {
ledcWrite(ledPins[0], 255 - r); //Common anode LED, low level to turn on the led.
ledcWrite(ledPins[1], 255 - g);
ledcWrite(ledPins[2], 255 - b);
}

Project 5.2 Gradient Color Light

In the previous project, we have mastered the usage of RGB LED, but the random display of colors is rather stiff. This project will realize a fashionable light with soft color changes.

Component list and the circuit are exactly the same as the random color light.

Using a color model, the color changes from 0 to 255 as shown below.

In this code, the color model will be implemented and RGB LED will change colors along the model.

Upload following sketch: LAFVIN_Super_Starter_Kit_For_Esp32_S3\Sketches\05.2_GradientColorLight

Sketch_05.2_SoftColorfulLight The following is the program code:

const byte ledPins[] = {38, 39, 40};  //define led pins
const byte chns[] = {0, 1, 2};        //define the pwm channels

void setup() {
for (int i = 0; i < 3; i++) {       //setup the pwm channels
    ledcAttachChannel(ledPins[i], 1000, 8, chns[i]);
}
}

void loop() {
for (int i = 0; i < 256; i++) {
    setColor(wheel(i));
    delay(20);
}
}

void setColor(long rgb) {
ledcWrite(ledPins[0], 255 - (rgb >> 16) & 0xFF);
ledcWrite(ledPins[1], 255 - (rgb >> 8) & 0xFF);
ledcWrite(ledPins[2], 255 - (rgb >> 0) & 0xFF);
}

long wheel(int pos) {
long WheelPos = pos % 0xff;
if (WheelPos < 85) {
    return ((255 - WheelPos * 3) << 16) | ((WheelPos * 3) << 8);
} else if (WheelPos < 170) {
    WheelPos -= 85;
    return (((255 - WheelPos * 3) << 8) | (WheelPos * 3));
} else {
    WheelPos -= 170;
    return ((WheelPos * 3) << 16 | (255 - WheelPos * 3));
}
}