connect XBee to the π via serial GPIO pins
listen for IO frames, which are of the form 0x7E....92
use a (manually maintained) mapping of 64-bit sensor addresses to apartments, to record apartment temperatures
Unlike XBee Zigbee, it supports synchronized sleeping, for low-power meshing.
The chip — this is the same hardware as XBee Series 1 but with DigiMesh firmware pre-installed.
The docs.
Adding a new node is slightly trickier, but if the π node is in "Synchronous Sleep Support Mode" SM=7, then you can just bring a new node near the π at any time and it will sync up with the rest of the sleeping (SM=8) nodes.
Can't both sleep and mesh, but has a better ADC, perhaps among other things.
Make sure to connect VREF to VCC. This is basically undocumented, but without it the chip basically crashes after a minute of reading from the ADC. TODO email Digi about this.
The chip, aka XBee Series 2.
The docs