free2p is a Raspberry Pi based solution that allows you to know if a bathroom is occupied or not via a web browser.

To make the server when the Raspberry Pi boots add the following line to your /etc/rc.local file before the exit 0 line:

(sleep 10; python3 path/to/server/folder/server.py) &

As an example, if the folder for the server is inside /usr/bin the you would add the line (sleep 10; python3 /usr/bin/free2p/server.py) &.

You can check how to wire the sensor any time by adding `/help.png` to the end of the free2p URL or address.

We used a Raspberry A+ with a Wi-Fi dongle and connected it to the local network:

Our "door locked" sensor consists of two springs installed with screws that connect via two wires to the raspberry pi:

(The raspberry pi is inside the white box. The spring wires go trough the wall and straight into the box)