Lesson 3: LED Control

Goal / 目標

Use LED to display system state visually.

API / 使用するAPI

Function	Description
ws::led_color(r, g, b)	Set LED color (0-255 per channel)
ws::is_armed()	Check ARM status
ws::battery_voltage()	Get battery voltage [V]

Steps / 手順

1. sf lesson switch 3
2. Show green when armed, red when disarmed
3. (Challenge) Display battery level as color gradient

Key Concepts / キーコンセプト

• WS2812 addressable LED
• State visualization
• Battery monitoring (3.3V-4.2V range for LiPo)