The GROVE-Luminance Sensor part of Seeed Studio is designed to measure the amount of light intensity, from sunlight to indoor lighting. Its sensitive photodiode is capable of sensing both visible and IR light, making it ideal for applications such as light adjusting, energy saving, color recognition, and UV detection. This module is extremely easy to use, and requires no external components, as it utilizes an on-board resister to convert the detected light intensity into an output voltage signal. It is extremely small, measuring only 15mm in diameter, making it suitable for any application that requires a compact form factor.