Hallo people!
maybe this is helpful for others.
I had this RF modules sent this morning and finally (evening) got them working.
the problem was that i had no comunication between the module on the computer (connected thru a USB to Serial board) and that on the Arduino. The Usb-Serial was in bundle with the two modules, and i've taken them here: Loading... BUT in the site, nor anywhere you can find this article, you are told about an issue with linux.
in fact the enable pin needs a voltage less than 1V or more than 3,5V, but with linux and mac you have just 3.45 on this pin, so the board isn't enabled.
SOLUTION:
to make the board work on linux or mac one solution is to make a little breakout board that just exclude the enable pin. This way the board is enabled and works ok!
if it was already known, i'm sorry, i didn't find this on this forum.
wish it's helpful for others.
Ciao!