Ok.. time to get some radio signals from the power outlets.
I'm using cheap 433 mhz power outlets from "Biltema".
Now we need to figure out the signals for these outlets. For that I'm using a cheap RF signal receiver connected to my Arduino UNO.
To "sniff" the signal I use the rc-switch library and one of the "receive" examples. Pressing a button on the socket remote gives you a nummer of values in the serial monitor. I'm interested in the "tristate" values so I note them down to be used for later when I will transmit.
Since I'm incapable of figuring this kind of stuff out myself I got inspiration on www.randomnerdtutorials.com