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. 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.
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. The BH1750 can measure from 0 to 65K+ lux, but with some calibration and advanced adjustment of the measurement time, it can even be convinced to measure as much as 100,000 lux!
1 * Adafruit BH1750 Light Sensor