# Adafruit BH1750 Ambient Light Sensor ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/093/303/medium800/adafruit_products_4681_iso_ORIG_2020_07_guide.png?1595023785) This is the BH1750 16-bit Ambient Light sensor from Rohm. Because of how important it is to humans and most other living things, sensing the amount of light in an environment is a common place to get started when learning to work with microcontrollers and sensors. Should we turn up the brightness of our display or dim it to save power? Which direction should your robot move to stay in an area with the most light? Is it day or night? All of these questions can be answered with the help of the [BH1750](https://www.mouser.com/datasheet/2/348/bh1750fvi-e-186247.pdf). It's a small, capable and inexpensive light sensor that you can include into your next project to add the detection and measurement of light. ![](https://cdn-learn.adafruit.com/assets/assets/000/093/305/medium800/adafruit_products_4681_quarter_ORIG_2020_07_guide.png?1595023931) The BH1750 provides 16-bit  light measurements in lux, the SI unit for measuring light making it easy to compare against other values like references and measurements from other sensors. Able to measure from 0 to 65K+ lux, the BH1750. With some calibration and advanced adjustment of the measurement time, it can even be convinced to measure as much as 100,000 lux! ![](https://cdn-learn.adafruit.com/assets/assets/000/093/306/medium800/adafruit_products_4681_kit_ORIG_2020_07_guide.png?1595023965) Sensors tend to come in small packages and the BH1750 is no different. Not much bigger than a grain of rice, this handy light sensing friend needs some help to be used by folks experimenting and without the desire or tools to work with surface mount parts. We're here to help! Packaged on a PCB in our **Stemma QT** form factor, the BH1750 comes integrated with a voltage regulator and level shifting circuitry to allow it to be used with 3.3V devices like a **Feather M4** or **Raspberry P** i, or **5V** devices such as an **Arduino**. Rather than working with the itty bitty little contacts on the sensor, the PCB it's packaged on breaks out all the pins to a standard 0.1 inch /2.54mm pitch header. ![](https://cdn-learn.adafruit.com/assets/assets/000/093/304/medium800/adafruit_products_4681_side_detail_ORIG_2020_07_guide.png?1595023809) To make things easier and a bit more flexible, we've also included [SparkFun Qwiic](https://www.sparkfun.com/qwiic) compatible [STEMMA QT](https://learn.adafruit.com/introducing-adafruit-stemma-qt) connectors for the I2C bus so you don't even need to solder! Just plug in a compatible cable and attach it to your MCU of choice and you’re ready to load up some software and measure some light. To help with the software part we’ve written a library that you can use with **CircuitPython** compatible devices as well as computers like the Raspberry Pi by installing it using PyPi. You can even use it on a full sized computer by using a [MCP2221 breakout.](https://www.adafruit.com/product/4471) **Arduino** users can use the well-crafted [hp\_BH1750](https://github.com/Starmbi/hp_BH1750) library by [Stefan Armborst](https://github.com/Starmbi)  and our installation instructions and wiring diagrams. - [Next Page](https://learn.adafruit.com/adafruit-bh1750-ambient-light-sensor/pinouts.md) ## Primary Products ### Adafruit BH1750 Light Sensor - STEMMA QT / Qwiic [Adafruit BH1750 Light Sensor - STEMMA QT / Qwiic](https://www.adafruit.com/product/4681) This is the **BH1750 16-bit Ambient Light Sensor** from Rohm. Because of how important it is to humans and most other living things, sensing the amount of light in an environment is a common place to get started when learning to work with microcontrollers and sensors. Should we... Out of Stock [Buy Now](https://www.adafruit.com/product/4681) [Related Guides to the Product](https://learn.adafruit.com/products/4681/guides) ## Featured Products ### STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable [STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable](https://www.adafruit.com/product/4209) This 4-wire cable is a little over 150mm / 6" long and fitted with JST-SH female 4-pin connectors on one end and premium Dupont male headers on the other. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert... In Stock [Buy Now](https://www.adafruit.com/product/4209) [Related Guides to the Product](https://learn.adafruit.com/products/4209/guides) ### JST SH 4-pin Cable with Alligator Clips - STEMMA QT / Qwiic [JST SH 4-pin Cable with Alligator Clips - STEMMA QT / Qwiic](https://www.adafruit.com/product/4398) This cable will make it super easy to use our plug-and-play STEMMA QT boards with boards like Circuit Playground. On one end you get a Qwiic / STEMMA QT connector (technically known as a JST SH 4-pin plug)  into 4 individual wires with grippy alligator clips. We're carrying these to... Out of Stock [Buy Now](https://www.adafruit.com/product/4398) [Related Guides to the Product](https://learn.adafruit.com/products/4398/guides) ### 4-pin JST PH to JST SH Cable - STEMMA to QT / Qwiic [4-pin JST PH to JST SH Cable - STEMMA to QT / Qwiic](https://www.adafruit.com/product/4424) Are you a maker in the midst of a [**STEMMA**](https://learn.adafruit.com/introducing-adafruit-stemma-qt/what-is-stemma) dilemma? This 200mm long 4-wire cable is a fantastic chimera-cable fitted with **STEMMA QT / Sparkfun Qwiic JST SH** on one end,... In Stock [Buy Now](https://www.adafruit.com/product/4424) [Related Guides to the Product](https://learn.adafruit.com/products/4424/guides) ### STEMMA QT / Qwiic JST SH 4-pin Cable with Premium Female Sockets [STEMMA QT / Qwiic JST SH 4-pin Cable with Premium Female Sockets](https://www.adafruit.com/product/4397) This 4-wire cable is a little over 150mm / 6" long and fitted with JST-SH female 4-pin connectors on one end and premium female headers on the other. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and... In Stock [Buy Now](https://www.adafruit.com/product/4397) [Related Guides to the Product](https://learn.adafruit.com/products/4397/guides) ### STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long [STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long](https://www.adafruit.com/product/4210) This 4-wire cable is a little over 100mm / 4" long and fitted with JST-SH female 4-pin connectors on both ends. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove. Out of Stock [Buy Now](https://www.adafruit.com/product/4210) [Related Guides to the Product](https://learn.adafruit.com/products/4210/guides) ## Related Guides - [IoT Power Outlet with CircuitPython and Adafruit IO](https://learn.adafruit.com/adafruit-io-a-c-power-relay.md) - [Ice Tube Clock Kit](https://learn.adafruit.com/ice-tube-clock-kit.md) - [Adafruit DACx578 - 8 x Channel I2C DAC](https://learn.adafruit.com/adafruit-dac7578-8-x-channel-12-bit-i2c-dac.md) - [Adafruit VEML6075 UVA / UVB / UV Index Sensor](https://learn.adafruit.com/adafruit-veml6075-uva-uvb-uv-index-sensor.md) - [Black Lives Matter Education & Workshop Kit](https://learn.adafruit.com/black-lives-matter-badge.md) - [Solderless Robot Toy Xylophone](https://learn.adafruit.com/solderless-robot-toy-xylophone.md) - [Feather TFT STEMMA Case](https://learn.adafruit.com/feather-tft-stemma-case.md) - [USB MIDI Host2Host](https://learn.adafruit.com/usb-midi-host2host.md) - [Flippy Floppy Drive Modification](https://learn.adafruit.com/flippy-floppy-drive-modification.md) - [Mini Pan-Tilt Kit Assembly](https://learn.adafruit.com/mini-pan-tilt-kit-assembly.md) - [Adafruit ESP32-S3 Reverse TFT Feather](https://learn.adafruit.com/esp32-s3-reverse-tft-feather.md) - [Adafruit Sensirion SHTC3 - Temperature & Humidity Sensor Breakout](https://learn.adafruit.com/adafruit-sensirion-shtc3-temperature-humidity-sensor.md) - [Adafruit New York and NYC DOE vendor information ](https://learn.adafruit.com/educational-orders-for-educators-based-in-new-york.md) - [Adafruit CH9328 UART to HID Keyboard Breakout](https://learn.adafruit.com/adafruit-ch9328-uart-to-hid-keyboard-breakout.md) - [Adafruit Ultimate GPS featherwing](https://learn.adafruit.com/adafruit-ultimate-gps-featherwing.md)