FHEM is a cool software utility with a web-based GUI that is used in conjunction with different hardware devices to control amongst others FS20 and HomeMatic devices.
CUL is a little USB stick that runs an opensource firmware. It can be used to control the above devices through the air.
apt-get install dfu-programmer
(depends on your hardware version which is visible on the stick)
define CUL1 CUL /dev/ttyACM0@9600 1234
define myActor FS20 12341234 0012
set the actor to the learning mode (by long-pressing the button) and send a on/off command through the webinterface to this actor.