In response to episode 267's request for projects based on wireless communications...
Episode 267: Ben Heck's Essentials Series: Wireless Communications
How about some form of a Bluetooth beacon type indoor location system.
Normally Bluetooth beacons are used more for advertisements however by monitoring signal strength then perhaps trilateration could be used with three or more Bluetooth beacons to provide a simple location framework for some interesting projects.
This perhaps might work well with the likes of the BBC Micro Bit, as the built-in compass could be used to give orientation information as well as using signal strength for distance.
If the beacons were set up as listening receivers as well, then trilateration could perhaps be used between beacons to calculate their relative locations to one another, and this could be combined with the on-board compass data for a North reference and/or triangulation. This information could then be transmitted by each beacon as its payload so that it broadcasts its orientation and the distance from each other beacon that is currently within range. A roving device (e.g. rover robot) can the use this to calculate position.
If using the iBeacon protocol then the UUID could be used to identify each beacon and then you have the 16bit major and minor integers to encode distance and compass information into.