Assignment 1: Blink - Control the addressable LED

Table of Contents

In this assignment you will initialize and control the onboard addressable LED in three different ways.

Understanding addressable LEDs
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WS2812 are individually addressable RGB LEDs. Each LED can display any color by mixing red, green, and blue values (0-255 each). The ESP32-C3-DevKit-RUST-2 board has one addressable LED on GPIO 2.

Work through the following tasks in your Assignment 1 Jupyter notebook:

Task 1: Initialize the addressable LED
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In this task, you’ll set up the addressable LED so your code can communicate with it. The neopixel.NeoPixel(machine.Pin(2), 1) line tells the chip which pin the LED is connected to (GPIO 2) and how many LEDs are being controlled (1 in this case).

neopixel_led = neopixel.NeoPixel(machine.Pin(2), 1)

Task 2: Set the Solid Colors
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Here, you’ll write helper functions to change the LED’s color. The set_color() function lets you set any RGB color by adjusting red, green, and blue brightness values from 0–255. The clear_led() function turns the LED off. You’ll then test the LED by cycling through a few example colors.

def set_color(r, g, b):
    """Set the addressable LED to a specific RGB color"""
    neopixel_led[0] = (r, g, b)
    neopixel_led.write()

def clear_led():
    """Turn off the LED"""
    set_color(0, 0, 0)


# Try different colors
set_color(255, 0, 0)  # Red
time.sleep(1)
set_color(0, 255, 0)  # Green
time.sleep(1)
set_color(0, 0, 255)  # Blue
time.sleep(1)
set_color(255, 255, 0)  # Yellow
time.sleep(1)
clear_led()

Task 3: Rainbow cycle effect
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This task adds a simple animation. You’ll create a rainbow_cycle() function that loops through a list of predefined colors — red, orange, yellow, green, blue, indigo, and violet — so the LED smoothly transitions through the rainbow spectrum.

def rainbow_cycle():
    """Cycle through rainbow colors"""
    colors = [
        (255, 0, 0),    # Red
        (255, 127, 0),  # Orange
        (255, 255, 0),  # Yellow
        (0, 255, 0),    # Green
        (0, 0, 255),    # Blue
        (75, 0, 130),   # Indigo
        (148, 0, 211)   # Violet
    ]

    for color in colors:
        set_color(*color)
        time.sleep(0.3)
    clear_led()

rainbow_cycle()

Task 4: Breathing Effect
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Now you’ll create a more dynamic lighting effect. The breathing_effect() function gradually fades the LED in and out using brightness scaling, giving a “breathing” glow. You can adjust the color, duration, and smoothness by changing the parameters.

def breathing_effect(r, g, b, duration=2, steps=50):
    """
    Create a breathing effect with the specified color
    """
    step_delay = duration / (steps * 2)

    # Fade in
    for i in range(steps):
        brightness = i / steps
        set_color(int(r * brightness), int(g * brightness), int(b * brightness))
        time.sleep(step_delay)

    # Fade out
    for i in range(steps, 0, -1):
        brightness = i / steps
        set_color(int(r * brightness), int(g * brightness), int(b * brightness))
        time.sleep(step_delay)

    clear_led()

breathing_effect(0, 100, 255)