N900 light meter

The light meter lets the software on the n900 sense ambient light levels.

Hardware

The device is a TAOS TSL2563.

Software

It is handled by the kernel module tsl2563.

The kernel driver exposes the lux value in the sysfs file

cat /sys/class/i2c-adapter/i2c-2/2-0029/lux
21

Third party applications that use this sensor include Luxus Light Meter.

The sensor is also used to modulate the backlight in response to ambient light.