Pat Peters (such a wonderful Marvel-sounding name) recently shared his take on the Weasley Clock, a device that hangs on the wall of The Burrow, the rickety home inhabited by the Weasley family in the Harry Potter series.

Mrs. Weasley glanced at the grandfather clock in the corner. Harry liked this clock. It was completely useless if you wanted to know the time, but otherwise very informative. It had nine golden hands, and each of them was engraved with one of the Weasley family’s names. There were no numerals around the face, but descriptions of where each family member might be. “Home,” “school,” and “work” were there, but there was also “traveling,” “lost,” “hospital,” “prison,” and, in the position where the number twelve would be on a normal clock, “mortal peril.”

The clock in the movie has misplaced “mortal peril”, but aside from that it looks a lot like what we’d imagined from the books.

There’s a reason why more and more Harry Potter-themed builds are appearing online. The small size of devices such as the Raspberry Pi and Arduino allow for a digital ‘brain’ to live within an ordinary object, allowing control over it that you could easily confuse with magic… if you allow yourself to believe in such things.

So with last week’s Real-life Daily Prophet doing so well, it’s only right to share another Harry Potter-inspired project.

The clock serves not to tell the time but, rather, to indicate the location of Molly, Arthur, and the horde of Weasley children. And using the OwnTracks GPS app for smartphones, Pat’s clock does exactly the same thing.

Pat has posted the entire build on instructables, allowing every budding witch and wizard (and possibly a curious Muggle or two) the chance to build their own Weasley Clock.

This location clock works through a Raspberry Pi which subscribes to an MQTT broker that our phones publish events to. Our phones (running the OwnTracks GPS app) send a message to the broker whenever we cross into or out of one of our waypoints that we have set up in OwnTracks; this then triggers the Raspberry Pi to run a servo that moves the clock hand to show our location.

There are no words for how much we love this. Here at Pi Towers we definitely have a soft spot for Harry Potter-themed builds, so make sure to share your own with us in the comments below, or across our social media channels on Facebook, Twitter, Instagram, YouTube and G+.