After recently watching one of the old Harry Potter movies, I became very interested in the Weasley family’s magically automated home, in particular, by their family clock, which displayed the location of the family members on a watch face under preset categories (home, school, traveling, in mortal peril, etc.) Although smartphone apps that allow people to share their location exist (such as Life 360 or Google Plus Locations), these apps are cumbersome to use, and offer too much information (so much that it raises some privacy concerns, even among friends and family). I decided to build a device that answers the question “Where is XX?” at a glance.
A watch face with independently moving hands would be extremely difficult to construct, so for my prototype I decided to display location through colored LEDs (one person per color) underneath generic symbols of their location (Home, Work, Traveling, Night out on the Town, etc.) Geo-fenced location data from Google Location Services for each phone is gathered by IFTTT (If This Then That), which then sends an email to a specific Gmail account viewed by another IFTTT account. The second IFTTT account reads the contents of the email, which signal if a user has entered or exited a geofenced location, and then adjusts the voltage output of the Cloudbit. The Arduino Mega polls the voltage output of the Cloudbit many times a second (through a connection between its analog input port and a Littlebits developer module. Each voltage corresponds to a specific movement, and the Arduino lights the corresponding LEDs to reflect the changes (if any) in location. The final result is a basic device that can display the answer to simple questions like “Has XX left work yet?” at a glance.