HOW to Use Rotary Encoder to Control RGB with ESP32

Introduction

In this lesson, we will control the LED on the RGB module to show different colors through a rotary encoder.

When designing the code, we need to divide the obtained values by 3 to get the remainders. The remainder is 0 and the LED will become red. The remainder is 1, the LED will become green. The remainder is 2, the LED will turn blue.

Components

Connection Diagram

Add Library

Open “Thonny”, click “This computer” → “D:” → “2. ESP32_code_MicroPython” → “lesson 49. Encoder control RGB”.

Select “rotary.py” and “rotary_irq_rp2.py”, right-click and select “Upload to /”, waiting for the “rotary.py” and “rotary_irq_rp2.py” to be uploaded to the ESP32.

Test Code

import time
from rotary_irq_rp2 import RotaryIRQ
from machine import Pin, PWM

pwm_r = PWM(Pin(0)) 
pwm_g = PWM(Pin(2))
pwm_b = PWM(Pin(15))

pwm_r.freq(1000)
pwm_g.freq(1000)
pwm_b.freq(1000)

def light(red, green, blue):
    pwm_r.duty(red)
    pwm_g.duty(green)
    pwm_b.duty(blue)

SW=Pin(27,Pin.IN,Pin.PULL_UP)
r = RotaryIRQ(pin_num_clk=12,
              pin_num_dt=14,
              min_val=0,
              reverse=False,
              range_mode=RotaryIRQ.RANGE_UNBOUNDED)

while True:
    val = r.value()
    print(val%3)
    if val%3 == 0:
        light(4950, 0, 0)
    elif val%3 == 1:
        light(0, 4950, 0)
    elif val%3 == 2:
        light(0, 0, 4950)
    time.sleep(0.1)

Code Explanation

In the experiment, we set the val to the remainder of Encoder_Count divided by 3. Encoder_Count is the value of the encoder. Then we can set pin GPIO0 (red), GPIO2 (green) and GPIO15 (blue) according to remainders.

Colors of the LEDs can be controlled by remainders.

Test Result

Connect the wires according to the experimental wiring diagram and power on. Click “Run current script”, the code starts executing. Rotate the knob of the rotary encoder to display the reminders, which can control colors of LED(red green blue). Press “Ctrl+C”or click “Stop/Restart backend”to exit the program.