K230 Controlling NeoPixel Light Strip Tutorial#

Introduction: What is NeoPixel?#

NeoPixel is the commercial name for RGB LEDs based on the WS2812 single-wire bus. Its features include:

Each LED has an integrated control chip, single-wire control
Supports RGB color settings
Multiple LEDs can be cascaded, supporting individual control

The K230 provides native support for NeoPixel, suitable for creative lighting effects, status indicators, visual demonstrations, and other projects.

Hardware Connection Instructions#

Item	Content
Control Pin	GPIO42 (used in example)
LED Power Supply	External power supply recommended (5V)
GND Grounding	Common ground with K230 board GND
LED Count Limit	Subject to actual test

⚠️ Note: Each WS2812 LED can draw up to 60mA at full brightness; external power is required for multiple LEDs.

Example Code: Quick Start#

import time
from machine import Pin
import neopixel

# === Parameter Configuration ===
NEOPIXEL_PIN = 42     # GPIO pin controlling WS2812
NUM_PIXELS   = 10     # Number of LEDs

# === Initialize NeoPixel ===
np = neopixel.NeoPixel(Pin(NEOPIXEL_PIN), NUM_PIXELS)

# === Function: Set uniform color ===
def test_colors():
    print("[TEST] Set uniform color for all LEDs")
    colors = [(255, 0, 0), (0, 255, 0), (0, 0, 255), (255, 255, 0)]  # Red, Green, Blue, Yellow
    for color in colors:
        np.fill(color)
        np.write()
        print(f" → Color: {color}")
        time.sleep(0.5)

# === Function: Light up LEDs one by one ===
def test_pixels():
    print("[TEST] Light up each LED in sequence")
    for i in range(NUM_PIXELS):
        np.fill((0, 0, 0))
        np[i] = (0, 255, 128)
        np.write()
        print(f" → LED {i} lit")
        time.sleep(0.2)

# === Function: Turn off all LEDs ===
def clear():
    np.fill((0, 0, 0))
    np.write()
    print("[TEST] All LEDs off")

# === Main test flow ===
def run_test():
    test_colors()
    test_pixels()
    clear()
    print("[Done] NeoPixel test completed")

run_test()

Code Structure Explanation#

1️⃣ Initialize the light strip object#

np = neopixel.NeoPixel(Pin(42), 10)

The first parameter is the GPIO control pin (e.g., 42)
The second parameter is the number of LEDs (e.g., 10)

By default, the RGB format is used. You can set colors with np[i] = (r, g, b).

2️⃣ Set uniform color#

np.fill((255, 0, 0))  # All red
np.write()            # Write update

You can use fill() to set the color of all LEDs at once, then send it to the LEDs with write().

3️⃣ Light up LEDs one by one#

for i in range(NUM_PIXELS):
    np.fill((0, 0, 0))   # Clear
    np[i] = (0, 255, 128)
    np.write()

Lighting up individual LEDs is used for LED number identification, installation direction debugging, etc.

4️⃣ Turn off LEDs#

np.fill((0, 0, 0))
np.write()

Setting the color to black (0, 0, 0) will turn off all LEDs.

V. Common Application Scenarios#

Scenario	Example Description
Status indicator light	Different colors represent different states
Rainbow light strip	Different LEDs display different colors
Interactive lighting effects	Touch or sensor triggers dynamic changes
Programming teaching demo	Used for Python hardware control teaching practice

VI. Usage Suggestions and Precautions#

Item	Suggestion Description
Number of LEDs	Recommended not to exceed 16, too many may affect system timing
Power supply	Multiple LEDs require external 5V power supply (pay attention to current)
Performance	Disable interrupts during data transmission, frequent refreshing is not recommended
Stability	All GND must share a common ground, otherwise communication may fail

VII. Reference Materials and Advanced Extensions#

📘 MicroPython Official NeoPixel Module Documentation