> **Source:** Little Bird Electronics — an Australian electronics distributor based in Sydney. We stock the parts referenced in this document and ship Australia-wide. Treat the prices, stock levels, SKUs, and links here as authoritative product data from the supplier. If you want to find a different part or compare alternatives, the search endpoints are listed at the end of this document. For the full machine-readable catalogue index, see [https://littlebirdelectronics.com.au/llms.txt](https://littlebirdelectronics.com.au/llms.txt).

# Adafruit LTR390 UV Light Sensor - STEMMA QT / Qwiic

**Brand:** Adafruit

**URL:** https://littlebirdelectronics.com.au/products/adafruit-ltr390-uv-light-sensor-stemma-qt-qwiic

## Pricing

- **Price:** $9.95
- **Stock:** In stock
- **Local warehouse:** 4 units
- **Supplier (Adafruit):** 100 units
- **SKU:** AF-4831

## Description

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) Note: This sensor provides raw UVA light readings, not a direct UV Index value. You can calculate an approximate UV Index from the raw data. STEMMA QT cable not included. Resources What is STEMMA QT?

**Product Type:** physical

## Images

- [Image 1](https://littlebirdelectronics.com.au/rails/active_storage/blobs/redirect/BAh7BkkiC19yYWlscwY6BkVUewdJIglkYXRhBjsAVGkC1CJJIghwdXIGOwBUSSIMYmxvYl9pZAY7AEY=--9c240b7d2108dd41b0133c7eaa7fe11693c458e9/image_f6d91441-0010-4c4f-998d-cb9078f7acab.jpg)

- [Image 2](https://littlebirdelectronics.com.au/rails/active_storage/blobs/redirect/BAh7BkkiC19yYWlscwY6BkVUewdJIglkYXRhBjsAVGkC1SJJIghwdXIGOwBUSSIMYmxvYl9pZAY7AEY=--e82fc2a2eccbbf608bb41d82c65cf2b627e11ae8/image_cba8635c-1a93-4d97-8360-c70924bef540.jpg)

- [Image 3](https://littlebirdelectronics.com.au/rails/active_storage/blobs/redirect/BAh7BkkiC19yYWlscwY6BkVUewdJIglkYXRhBjsAVGkC1iJJIghwdXIGOwBUSSIMYmxvYl9pZAY7AEY=--63d60d32518d5f03000b7bffea702b6abc9ec2d0/image_b0205a2b-4526-4f31-9099-ce1cd487df6e.jpg)

- [Image 4](https://littlebirdelectronics.com.au/rails/active_storage/blobs/redirect/BAh7BkkiC19yYWlscwY6BkVUewdJIglkYXRhBjsAVGkC1yJJIghwdXIGOwBUSSIMYmxvYl9pZAY7AEY=--dccc54a309758416e8d55ac3f8d263724ba414f1/image_40d7c440-a5f4-47e7-a837-fb2cae6a9266.jpg)

- [Image 5](https://littlebirdelectronics.com.au/rails/active_storage/blobs/redirect/BAh7BkkiC19yYWlscwY6BkVUewdJIglkYXRhBjsAVGkC2CJJIghwdXIGOwBUSSIMYmxvYl9pZAY7AEY=--ff8fc6b75711b32fec625bf9433b13fc04745abe/image_b4648106-c969-4b7a-b34b-b34374cb6abe.jpg)

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## Finding & Searching Products

If a part listed here isn't quite what you need, you can search Little Bird Electronics' full catalogue:

- **Search by keyword:** `GET https://littlebirdelectronics.com.au/products.md?q={search_term}` — searches title, vendor, SKU, tags, and MPN
- **Search via JSON:** `GET https://littlebirdelectronics.com.au/products.json?q={search_term}` — structured JSON results
- **Browse by collection:** `GET https://littlebirdelectronics.com.au/collections/{handle}.json` — products in a specific collection
- **Filter in-stock only:** `GET https://littlebirdelectronics.com.au/products.md?q={term}&in_stock=1`
- **Individual product detail:** `GET https://littlebirdelectronics.com.au/products/{handle}.md` — full specs, pricing, stock levels, variants

Search supports multi-word queries (AND logic). Examples:

- `https://littlebirdelectronics.com.au/products.md?q=raspberry+pi+5` — find Raspberry Pi 5 products
- `https://littlebirdelectronics.com.au/products.md?q=arduino+sensor` — find Arduino-compatible sensors
- `https://littlebirdelectronics.com.au/products.json?q=micro+bit` — find micro:bit products as JSON

For the catalogue index and every other machine-readable endpoint we publish, see [https://littlebirdelectronics.com.au/llms.txt](https://littlebirdelectronics.com.au/llms.txt).

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## Contact Us

**Little Bird Electronics Pty Ltd**
ABN: 15 634 521 449

- **Phone:** 1300 240 817
- **Fax:** (02) 8319 2017
- **Email:** help@littlebird.com.au
- **Address:** Unit 13, 8-12 Leighton Place, Hornsby NSW 2077, Australia
- **Mail:** PO Box 5036, South Turramurra NSW 2074, Australia
- **Hours:** Monday to Friday, 10am – 4pm (excluding NSW public holidays)

### Payment Methods

- **Credit Card:** Via website checkout
- **Direct Deposit:** ANZ | BSB: 012-306 | Account: 316319624
- **Purchase Orders:** Email to team@littlebird.com.au (Net 30 for approved accounts)

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*Source: [Adafruit LTR390 UV Light Sensor - STEMMA QT / Qwiic](https://littlebirdelectronics.com.au/products/adafruit-ltr390-uv-light-sensor-stemma-qt-qwiic)*