Adafruit LTR390 UV Light Sensor - STEMMA QT / Qwiic
We have ✅ 6 available of the AF-4831 in our Sydney warehouse. An extra 100 units available with a short lead time.
The Adafruit LTR390 is a dual-purpose UV and ambient light sensor with true UVA sensing at a peak spectral response between 300 and 350 nm. Unlike UV index approximation sensors, the LTR390 has a genuine UV photodiode — giving you real ultraviolet light measurements over a simple I2C interface.
The sensor also provides ambient light readings, making it useful for both UV exposure monitoring and general light level detection. The biasing and ADC are all internal, so no external components are needed. This STEMMA QT breakout includes voltage regulation and level shifting for both 3.3 V and 5 V systems.
Key Features
- True UVA Sensing – Real UV photodiode with peak response at 300–350 nm
- Ambient Light Sensing – Dual-mode sensor for both UV and visible light measurements
- Internal ADC – No external analogue-to-digital converter required
- I2C Interface – Simple two-wire communication
- STEMMA QT / Qwiic – Solderless I2C connectors for easy plug-and-play wiring
- 3.3 V and 5 V Compatible – Onboard voltage regulator and level shifting
Ideal For
- UV exposure monitoring and sun safety projects
- Weather stations with UV index estimation
- Ambient light sensing and display brightness control
- Environmental monitoring and wearable UV trackers
Package Contents
- 1× Adafruit LTR390 UV Light Sensor Breakout (STEMMA QT)
Resources
The Adafruit LTR390 UV Light Sensor - STEMMA QT / Qwiic appears in the following collections:
