This device is based on SI1145, a new sensor from SiLabs. The Si1145 is a low-power, reflectance-based, infrared proximity, UV index and ambient light sensor with I2C digital interface and programmable-event interrupt output.
This device offers excellent performance under a wide dynamic range and a variety of light sources including direct sunlight.
The Grove - Sunlight Sensor include an on-bard Grove connector, which help you to connect it your Arduino easily.

Features:

• Digital light sensor
• Wide spectrum detection range to improve accuracy.
• Programmable configuration which make it versatile for various applications.
• Detect sunlight directly
• Grove compatible
• I2C Interface (7-bit)