python-editor/LED_TUTORIAL.md

Python LED Tutorial (NeoPixel Focus)

This tutorial is for the browser editor's ESP32-style mocks:

• machine.Pin
• neopixel.NeoPixel

Use workspace/code/led_tutorial.py while reading this guide.

1) Basic setup

from machine import Pin
import neopixel

np = neopixel.NeoPixel(Pin(4), 12)

• Pin(4) means data pin 4 (matching common ESP32 examples).
• 12 is the number of LEDs in the strip/ring.
• np is your LED strip object.

2) Set one LED color

np[0] = (255, 0, 0)  # red
np.write()

• Colors are (red, green, blue) from 0 to 255.
• Nothing updates visually until np.write().

3) Fill all LEDs

np.fill((0, 0, 255))  # all blue
np.write()

4) Clear LEDs (turn off)

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

5) Animate over time

import time

for step in range(20):
    np.fill((step * 10, 0, 255 - step * 10))
    np.write()
    time.sleep(0.08)

time.sleep(...) controls animation speed.

6) Moving pixel example

for i in range(len(np)):
    np.fill((0, 0, 0))
    np[i] = (255, 120, 0)
    np.write()
    time.sleep(0.06)

7) Tips

• Keep color values in 0..255.
• Use helper functions for repeated color logic.
• Start with short loops, then increase frames once behavior looks good.
• If the simulator is closed, run your script again to show updates.