@antonholmstedt a pro mini fits if you cut the corners, check out https://forum.mysensors.org/topic/6612/door-sensor-remix-of-some-mys-community-efforts
I liked domoticz (was very easy to set up and use). Together with dzVents scripting wasn't that difficult either. But I also had some problem with it lately, so I was actually thinking about switching to openhab (2).
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.
FYI: RadioHead library 1.34 has some specific initialization code for RFM73 in the nRF24 driver (e.g. ACTIVATE command).
See https://github.com/Yveaux/RadioHead/commit/f895ba933950681234d714fd7c3d3c18658b8ed5
