Steve Kasuya took to Twitter to show off his homage to Studio Ghibli’s Laputa: Castle in the Sky. It’s a Raspberry Pi Pico-powered black stone with engraved Laputan characters which light up when you pass the “flying stone” over the top of them.

What is this land of Laputa of which you speak?

I’ll hazard a guess that there’s a sizeable number of you in the centre section of a Venn diagram featuring Raspberry Pi enthusiasts on one side and Studio Ghibli fans on the other, but I am not one of those people, so have enlisted The MagPi‘s Rob to explain:

As the resident weeb of Raspberry Pi Towers, it’s my job to explain the role of the crystal “flying stone” pendant and control tablet in the film Laputa: Castle in the Sky. The crystal pendant belongs to a mysterious girl who can use it to float, and is an access key to a floating castle called Laputa. As well as being used to make the castle float, cast a magical protective barrier, and ultimately destroy Laputa, the pendant opens doors and controls various aspects of the castle via the black stone – which incidentally you can buy as a paperweight from the Studio Ghibli museum.

Laputa is enormously influential on Japanese media – a lot of Studio Ghibli movies are to be fair – and a lot of Japanese steampunk takes inspiration from it. Even a lot of early Sonic games seem to draw inspiration from it, especially in the setting for Sonic 3 and even in the design of Dr Robotnik/Eggman.

As for the crystal-controlling-a-computer-via-a-slab thing, you may also recognise it as the computer system the alien Asgard use in the TV show Stargate SG-1.

Does that all make sense? Good. Moving on.

How does it work?

Steve shared this project in a short thread of tweets so details are a bit thin on the ground, but, in a nutshell, some red LEDs are mounted below the surface of what looks like a 3D-printed or laser-cut black stone tablet. Laputan letters are cut into the surface and the LEDs are positioned to shine through them.

There’s a MicroPython program that communicates between the flying stone and the tablet’s LEDs to make them light up when the flying stone passes over the letters. A single Raspberry Pi Pico powers the whole thing. The LEDs have a nice smooth on/off transition, so it looks really magical when they light up.