I looking with a magnifying glass at the chip, i noted that this is NOT NRF24L01+ but just a NRF24L01 without the plus.
I used this smaller versions and they worked immediately. I_GATEWAY_READY message appeared. http://www.ebay.com/itm/2-4G-NRF24L01-PA-LNA-Wireless-Module-with-Ceramic-Antenna-1-27mm-/400746941364?pt=LH_DefaultDomain_0&hash=item5d4e610bb4
MySensors did post a warning on that: http://forum.mysensors.org/topic/728/radio-setup-give-check-wires/16
THREAD RESOLVED.
I have already published all the documentation, on my website, GitHub and openhardware.io
For now I leave the node as finished.
SmartHome: Wireless LED RGBW Controller – 00:55— giltesa
I see a lot of "!TSF" and "NACK" which seems to be radio communication problems.
That's MySensors related and can be related to many things, from soldering problem to power / capacitor issues.
In MY_DEBUG mode you should see your temp/hum printed on serial every ~15s so there is something wrong there, either wiring or a code issue.
Ty with the example included with the library "i2c_SI7021.h", without any MySensors related stuff, to see if your sensor is detected. You should see temp/hum on the serial.