Small update:
After some more testing I think that USB port on the wireless system is only usefull for keyboard/mouse. Those companies crippling there hardware by software are really annoying, as there are normal USB controller chips on the boards, they are just set up in a very specific way. Bad news!
So, two options left:
-
Using the "remote control" channel of the wireless system that is desigend for transmitting the infrared pulses of a remote control.
Pros: no extra receiver/transmitter, very strong wireless connection. Cons: only one "wire" so I will have to work with frequency modulation (which makes it a slow connection), not future proof as other HDMI wireless kits might not work the same way. -
Building a wireless system with Arduino and the Xbee boards.
Pros: future proof/independent of the HDMI wireless kit, I can set it up to my specific needs. Cons: extra receiver/transmitter (consuming more money, power, space, weight,..)
I think I will go with 2) using Arduino with the Xbee boards. Has anybody used two Arduinos with a Xbee (series-1) each to set up a simple point-to-point connection and can comment on reliability in real world usage, especially how it works with no direct line-of-sight of receiver/transmitter?