The first challenge set to our new hacker-in-residence, George Koulouris, was to make an innovative doorbell for the ICRS Lab. The door to the ICRS Lab is a distance from the main working space. This poses a problem for people knocking on the door; no one can hear them.
A Raspberry Pi, a wifi dongle, some speakers, a sheet of MDF, a laser cutter and a web hosting service were all brought together to form a high tech hacked doorbell.
Using a QR code on the front door, the user is directed to a specific webpage. When the webpage is accessed a .txt file is changed from 'OFF' to 'ON'. The Raspberry Pi with wifi dongle (permanently connected to the internet) checks this file every second. When the Raspberry Pi detects the change it activates the doorbell, returns the text file to the 'OFF' state and updates the webpage to inform that the doorbell has been activated.
For a detailed description of how to make this contraption head over to: http://www.instructables.com/id/Open-Sesame/. Thanks George!