Purpose: Measures ambient light intensity, infrared (IR), and ultraviolet (UV) radiation levels.
Typical Use Cases: Smart lighting, wearables, environmental monitoring, sun exposure tracking.
Common Sensors:
- Si1145/Adafruit SI1145: Integrated sensor for visible, IR, and UV index.
- VEML6075: Dedicated UV sensor with UVA/UVB photodiodes.
- APDS-9301/9306: Ambient light and IR digital converter.
Interface: I²C (most common), SPI optional on some models.
Voltage Range: 2.5V – 5.5V (check datasheet).
Key Features:
- Separate channels for visible, IR, and UV light
- Digital output with programmable gain/integration time
- Low power consumption for battery operation
- Some include interrupt support for threshold detection
Design Tips:
- Place sensor under clear lens or window; avoid tinted covers.
- Shield from internal PCB IR sources (e.g., LEDs).
- Use bypass capacitor (0.1µF) near power pins.
- Calibrate against known light source if high accuracy needed.