We met Stuart Pemberton about four weeks ago when we were installing some art at the Lost Gardens of Heligan. Stuart is an electrical contractor at Heligan, and as we cut and trimmed wires, discussed onions, went up and down ladders (him, not me) and shot the breeze our common Raspberry Pi interest came up. Unlike me with my 34 long years of coding experience, Stuart is strictly a wires and volts guy, and had not yet written a line of code in any language. But he had stepped up to the plate in a big way and volunteered to get to grips with enough Python to put together a hardware / software project for Heligan Halloween - an interactive exhibit with infra-red sensors, audio playback and owls. And I like a nice owl, so I thought the whole thing was dead cool, and was very interested to hear how it all went on.
And here we are, four weeks later, back at Heligan to deinstall some art, and flipping heck, he's only gone and done it! Dude!!! In a remarkably serendipitous bit of timing, Stuart had just finished attaching the final wire and run the final tests when we bumped into him at lunch yesterday, so we had to take a look.
There's a grey box with a Pi, an audio amplifier, a PIR sensor to detect passing warm bodies, and a loudspeaker up a tree. Some Python, an OMXplayer, a recording of a tawny owl hooting, and hey presto, instant Halloween attraction, with passing children enchanted by the hooting owl and wondering a) where it is and b) how come it hoots every time they walk by. Brilliant!
Here he is with his baby - the Pi, PIR and audio amp are in the grey box, hidden under leaves, the pair of 12V batteries powering the whole thing are also hidden under leaves slightly out of shot to the left.
Here's a badly-shot video of the thing - if you listen carefully the owl hoots a couple of times during this.
This forms part of the Heligan Halloween celebrations, running from now until November 2nd (that's 2014 if for some reason you are reading this in the far future). It is along the Woodland Walk, not too far from the Mud Maid and the Giant's Head, and also close to an excellent and a wee bit creepy child-sized spider's web installation. So jump in the car and head for Cornwall right now.
UPDATE!!! We just heard from Lorna at Heligan that in fact the project was too successful - gardeners and visitors wandering around at dusk were triggering the recording, which was then attracting actual female tawny owls to the tree! Nice if you want to see a female tawny at dusk, but not at all fair - not nice if you're a girl owl looking for a guy and all you can find is a loudspeaker, and of course it may stop other owl pairs breeding in the area if they think a dominant, hooty male is in residence. So the recording is now of a wolf. A nice, non-British sort of animal. And werewolves are very Halloween. We trust the wolf sound is sufficiently alien that none of the native wildlife is either concerned by, or taken in by the sound!