With a group of friends we decided to explore the wireless side of arduino. Searching a bit on google we found a nice and really cheap 2.4GHZ module, the NRF24L01+ module for about 2.60 euros a couple (what the heck do you need just one for?).
To make it communicate with the other arduino the first thing to do is use the right pinout scheme, which must match the library pinout (of course).
pinouts taken from http://arduino-info.wikispaces.com/Nrf24L01-2.4GHz-HowTo (dupon color coded)
We decided to use for our first test the RF24 library (click here for github page), but the devices were not working. Actually they were not communicating correctly. An arduino was transmitting but the other one was not receiving or sometimes it was not sending back the ACK packet.
We’ve spent a bunch of hours, checking dupons, changing arduinos (one of them was actually malfunctioning), changing the radio module and even changing pinouts (who knows… mystic events happening), changing cables.
Then, at 4AM, I decided to start from scratches. Following this (awesome) guide from [maniacbug] I downloaded again the RF24 library, uploaded the GetStarted sketch to the arduinos, connected the radios, and everything was working!
The only reason I can imagine is something about a corrupted library (was from another source) , outdated files, or a divine intervention from Stallman.
Will post again on evolving projects.