Durin's box, designed and built by John Pender on Hackaday, is a prime example of the supreme nostalgia a Raspberry Pi project can invoke. Built around a Pi Zero, it uses solenoids, capacitive switches, RGB LEDs, a microphone and a voice recognition solution to remind us of the moonlit magic of Dwarves, and just how forgetful Wizards can be.
Designed and put together form scratch, the box was a gift for Pender's son. If you can't read Elvish, it says "Speak friend and enter." But there's a little more to opening it than just speaking the Elvish word for friend. Move over Frodo.
First you have to turn it on by touching the two points marked by stars, beneath which sit two capacitive switches. That sends power to the Raspberry Pi, which in turn lights up the inscription with RGB as if it's been touched by moonlight, and the microphone awaits the answer to the riddle.
On speaking the word "Mellon," the treasures within will reveal themselves. Well, you have to lift the box lid yourself, but the two solenoids on the lids underside retract to let you do so. They return to their original position pretty quickly, which means you'd have to wait a fair while for the thing to boot up again just to lock it if you don't put the lid back in time, but I like to imagine Dwarves tend to have similar issues with their doors, too.
The trick with getting it to recognise the password was to use PocketSphinx, a non-cloud based voice recognition tool which doesn't need pre-training. Seeing as it was a gift, I think the son might've suspected something if his father came up with a recording device like, "Hey son, can you just tell me the Elvish for friend again, please? Bit louder."
It doesn't look like you could fit a dragon's hoard under the lid, but perhaps something a little more... precious. Though, in the words of Thorin Oakenshield: "If more of us valued food and cheer and song above hoarded gold, it would be a merrier world." So maybe it could be a secret box of snacks?
The danger, of course, would be forgetting the password and having your stack of Lembas bread go stale. Lets face it, even if you once knew every spell in all the tongues of Elves, Men, and Orcs, it could still happen.
If that occurs, the thing glitches out, or the battery dies, there is a failsafe for getting those solenoids moving. Simply jolting the capacitive switches with a little voltage will get them to shift.
Hats off to Pender for his supreme craftsmanship, and for making one of my childhood dreams a reality. Keep on hacking.