utschu wroteThis shouldn't be a problem if you do the configuration by use of a router connection and assign a fixed ip Adress, you should be able to connect to the predefined IP adress leater on without having a router connected (as long as the control device will be configured to an IP sdress range of the same group).
Sorry, but this isn't quite that simple. You still need "some kind" of a router - i.e. one of the devices needs to "do the stuff" that a router does, practically turning the device into a wireless access point.
It is possible, though, to use the RPi with wifi control without a router: you need a wifi card for the RasPi that has the access point ("hostap") capability:
http://elinux.org/RPI-Wireless-Hotspot
Google "raspberry pi hotspot" and see for yourself.
Denis