1TSL2550 Driver (Ambient Light Sensor) 2===================================== 3 4Overview 5-------- 6 7This is the driver for the ambient light sensor commonly found on the 8WeatherCape expansion board for the BeagleBone. 9 10Interface 11--------- 12 13This driver implements the character device interface. It supports reading 14through /dev/tsl2550b{1,3}s39. When read from, it returns a string containing 15a data label, a colon, and the sensor value. 16 17Example output of `cat /dev/tsl2550b3s39`: 18 19ILLUMINANCE : 830 20 21Illuminance is expressed in lux. Valid values are 0 to 1846. 22 23Limitations 24----------- 25 26Extended mode isn't implemented. Normal mode should be sufficient for most 27applications. 28 29Testing the Code 30---------------- 31 32The driver should have been started by a script in /etc/rc.capes/ If not, 33this is how you start up an instance: 34 35cd /dev && MAKEDEV tsl2550b3s39 36/sbin/minix-service up /service/tsl2550 -label tsl2550.3.39 \ 37 -dev /dev/tsl2550b3s39 -args 'bus=3 address=0x39' 38 39Getting the sensor value: 40 41cat /dev/tsl2550b3s39 42 43Killing an instance: 44 45/sbin/minix-service down tsl2550.3.39 46 47