Based on a CdS cell and LM358 output buffer, this Grove light sensor is a handy solution for light-intensity measurements. The value goes down as the light intensity rises. The datasheet gives you a table for calculating the general lux level read by the sensor.

Specifications

• Grove compatible interface (analog)
• GL5528 CdS sensor
• 540nm Peak sensitivity
• 3~5VDC
• 0.5~3mA
• Light to Dark resistance: 20k~1M

Links

• Arduino
• Raspberry Pi
• LinkIt
• TI LaunchPad
• Github – Grove_Light_Sensor
• Light Sensor wiki