6.5 Color Gradient

Are you ready to experience a world of color? This project will take you on a magical journey where you can control an LED strip and achieve smooth color transitions. Whether you’re looking to add some color to your home decor or seeking a fun programming project, this project has got you covered. Let’s dive into this colorful world together!

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
ESP32 Starter Kit	320+	ESP32 Starter Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION	PURCHASE LINK
ESP32 WROOM 32E	BUY
ESP32 Camera Extension	-
Breadboard	BUY
Jumper Wires	BUY
Potentiometer	BUY
WS2812 RGB 8 LEDs Strip	BUY

Schematic

This project uses an LED strip and a potentiometer to create a color mixing effect. The potentiometer is used to adjust the hue value of the LED, which is then converted into RGB values using a color conversion function. The RGB values are then used to update the color of the LED.

Wiring

Code

Note

• Open the 6.5_color_gradient.py file located in the esp32-starter-kit-main\micropython\codes path, or copy and paste the code into Thonny. Then, click “Run Current Script” or press F5 to execute it.

• Make sure to select the “MicroPython (ESP32).COMxx” interpreter in the bottom right corner.

from machine import Pin, ADC, PWM
import neopixel
import time

NUM_LEDS = 8  # Number of LEDs in the strip
PIN_NUM = 26  # LED strip
POT_PIN = 14  # Potentiometer

# Initialize the potentiometer
potentiometer = ADC(Pin(POT_PIN))
potentiometer.atten(ADC.ATTN_11DB)

# Initialize the NeoPixel LED strip
np = neopixel.NeoPixel(Pin(PIN_NUM), NUM_LEDS)

# Function to convert HSL color space to RGB color space
def hsl_to_rgb(h, s, l):
    # Helper function to convert hue to RGB
    def hue_to_rgb(p, q, t):
        if t < 0:
            t += 1
        if t > 1:
            t -= 1
        if t < 1/6:
            return p + (q - p) * 6 * t
        if t < 1/2:
            return q
        if t < 2/3:
            return p + (q - p) * (2/3 - t) * 6
        return p

    if s == 0:
        r = g = b = l
    else:
        q = l * (1 + s) if l < 0.5 else l + s - l * s
        p = 2 * l - q
        r = hue_to_rgb(p, q, h + 1/3)
        g = hue_to_rgb(p, q, h)
        b = hue_to_rgb(p, q, h - 1/3)

    return (int(r * 255), int(g * 255), int(b * 255))

# Function to set the color of all LEDs in the strip
def set_color(np, color):
    for i in range(NUM_LEDS):
        np[i] = color
    np.write()

# Main loop
while True:
    # Read the potentiometer value and normalize it to the range [0, 1]
    pot_value = potentiometer.read() / 4095.0
    hue = pot_value  # Set hue value based on the potentiometer's position
    saturation = 1  # Set saturation to 1 (fully saturated)
    lightness = 0.5  # Set lightness to 0.5 (halfway between black and white)

    # Convert the HSL color to RGB
    current_color = hsl_to_rgb(hue, saturation, lightness)

    # Set the LED strip color based on the converted RGB value
    set_color(np, current_color)

    # Sleep for a short period to allow for smooth transitions
    time.sleep(0.1)

As the code runs, slowly rotate the potentiometer and you will see the color of the RGB Strip fade from red to purple.