Rachel Gregory, over at IoT company Initial State, has just published an excellent tutorial that takes you through the steps required to write a “who’s at home/who’s in the office” service. The tutorial uses a Raspberry Pi Zero (any Pi will work) to detect devices connected to a wifi network. It then does a look-up against lists of people and MAC addresses to determine who is connected. The results are streamed to Initial State where a dashboard is created. It’s an excellent example of using services, scripting and programming together and while it’s not perfect – what happens if someone forgets their phone? – it’s a cool little Internet of Things project. Take a look at the tutorial here.