After a lot of experimentation, research and prototyping, I finally have all the parts I need to finish my PIR sensors. I plan to have one in each room, well almost.
They will have two functions. Primarily they will be used to track us and switch lights and heating (Nexa remote switches) as appropriate when we are home. The switching will follow certain rules, like time of day, who is home, weekday, weekend etc. When no one is home, they will be part of the security system and notify us, using Pushbullet, if they sense movement while we are not home. Both functions will be controlled by DomotiGa running on a Raspberry Pi, using a RFXCOM rfxtrx433e USB transceiver.