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

Code

We need to create three PWM channels and use random duty cycle to make random RGBLED color. Move the program folder “Basic_Starter_Kit_for_ESP32_S3/Python/Python_C odes” to disk(D) in advance with the path of “D:/Micropython_Codes”.

Open “Thonny”, click “This computer” >> “D:” >> “Micropython_Codes” >> “05.1_Random ColorLight”and double click “RandomColorLight.py”.

05.1_RandomColorLight

Click “Run current script”, RGBLED begins to display random colors.

The following is the program code:

from machine import Pin,PWM
from random import randint
import time

pins=[38,39,40]

pwm0=PWM(Pin(pins[0]),10000)
pwm1=PWM(Pin(pins[1]),10000)
pwm2=PWM(Pin(pins[2]),10000)

def setColor(r,g,b):
    pwm0.duty(1023-r)
    pwm1.duty(1023-g)
    pwm2.duty(1023-b)

try:
    while True:
        red   = randint(0,1023)
        green = randint(0,1023)
        blue  = randint(0,1023)
        setColor(red,green,blue)
        time.sleep_ms(200)
except:
    pwm0.deinit()
    pwm1.deinit()
    pwm2.deinit()

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 RGBLED will change colors along the model. Open “Thonny”, click“This computer” >> “D:” >> “Micropython_Code s” >> “05.2_GradientColorLight” and double click “GradientColorLight.py”.

05.2_GradientColorLight

The following is the program code:

from machine import Pin,PWM
import time

pins=[15,2,0];

pwm0=PWM(Pin(pins[0]),1000)
pwm1=PWM(Pin(pins[1]),1000)
pwm2=PWM(Pin(pins[2]),1000)

red=0                  #red
green=0                #green
blue=0                 #blue

def setColor():
    pwm0.duty(red)
    pwm1.duty(green)
    pwm2.duty(blue)

def wheel(pos):
    global red,green,blue
    WheelPos=pos%1023
    print(WheelPos)
    if WheelPos<341:
        red=1023-WheelPos*3
        green=WheelPos*3
        blue=0

    elif WheelPos>=341 and WheelPos<682:
        WheelPos -= 341;
        red=0
        green=1023-WheelPos*3
        blue=WheelPos*3
    else :
        WheelPos -= 682;
        red=WheelPos*3
        green=0
        blue=1023-WheelPos*3

try:
    while True:
        for i in range(0,1023):
            wheel(i)
            setColor()
            time.sleep_ms(15)
except:
    pwm0.deinit()
    pwm1.deinit()
    pwm2.deinit()