Digital signal processing with teeny-tiny tap-dancers.

When we wrote about accelerating Fast Fourier Transforms (FFTs) on the Pi back in January, several people asked what sort of real-world application FFTs can have. We talked about numerical analysis, cryptography, spectrograms and software-defined radio, among other things, in the comments on that post. All the same, FFTs are something that those who don’t get excited by maths can find a bit dry, and it can be hard to find a good demonstration of FFTs that works for those of you who like to think about things visually. So I was really pleased to find a link to this project from Pavan Tumati, which makes digital signal processing…decorative. Not to mention festive.

Here, FFTs are performed on music samples on the Raspberry Pi fast enough to detect a beat, and the Pi relays that information to some teeny-tiny tap-dancers, who produce an automated routine that’s synced to the music.

These little tap-dancing guys are from a post-Christmas sales bin. They’re called Happy Tappers, and are made by Hallmark, who, for reasons known only to them, include a port which enables them to interface with their tippy-tapping brothers and sisters – which makes for exciting DIY project possibilities once you add something that’s able to feed them an input. I’ve never seen them on sale in the UK, but if you’re dead set on making your own tap-dancing Pi project, they seem to be available online at eBay, Amazon US, and at some Christmas shops.

(I know: it’s a bit odd posting about Christmas decorations in mid-March. But if the family across the road from me, who still have multicoloured lights flashing away merrily on the tree in their front garden every evening, are anything to go by, Christmas decorations aren’t just for Christmas any more.)

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