TSL2561

• http://www.adafruit.com/product/439

   Approximates Human eye Response
   Precisely Measures Illuminance in Diverse Lighting Conditions
   Temperature range: -30 to 80 *C
   Dynamic range (Lux): 0.1 to 40,000 Lux
   Voltage range: 2.7-3.6V
   Interface: I2C
   This board/chip uses I2C 7-bit addresses 0x39, 0x29, 0x49, selectable with jumpers

• https://github.com/adafruit/TSL2561-Arduino-Library
• Karl Maxwell code in mbed public repository