Even though I read some forums before regarding the problems between the rpi and the k400r keyboard, I decided to buy them saying, oh well, I can be on the lucky side. I wasn’t.
Or at least that’s what I thought :)
So, what to do first with the little thing? A media center of course. So I installed Raspbmc (latest stable release) at work with a wired keyboard. All good. Everything went smooth, without problems. Once I got home where I have the K400r wireless keyboard, I realised that the Raspberry Pi is not responding to any keyboard presses. So next thing to do was to search over the internet for fixes, some of them like: Kernel Rebuilding, some configuration files editing, installation of drivers, changing the receiver and so on. NONE OF THEM WORKED. I lost many hours trying to fix this issue before dropping Raspbmc.
Next: I installed Openelec. Same thing. Nothing worked.
After extending the searches, I found a solution on a forum and I said, no way it’s too easy. But, IT WORKED.
The thing is that before I put the keyboard on Raspberry PI, I put in on my laptop and after I finished testing the keyboard, I unpaired the receiver and the keyboard. That was the problem. That thing made me lose so many hours.
So, if you have a Raspberry Pi and Logitech K400R wireless keyboard, make sure the small receiver and the keyboard are paired first, and only after that, if it’s still not working, try the other stuff.