Mike Cook’s Magic Wand

Mike Cook, electronics Superman, swapped some emails with us after we last posted about one of his projects. Eben and I both wanted to talk to him about a feature from Mike’s Body Building column in Micro User from 1989, where Mike made a magic wand that wrote letters in the air.

BBC Micro User, July 1989

I read the magazine and lusted after the thing; but at my girl’s boarding school in rural Bedfordshire, where we didn’t have an electronics lab (although we did have a huge domestic science suite), mercury switches and leds were about as easy to get your hands on as unicorn poo – you could buy a kit from the magazine, but I’d spent all my money on bubble gum and cello rosin. Eben had a very lucid memory of that particular column too, and hadn’t been able to get the parts either. We both mentioned that it was our favourite design from the Body Building column while thanking him for the projects he’s done with a Raspberry Pi so far. (Mike, ever self-effacing, says that similar projects have been done a million times since then, but he does believe that this was the first time such a thing ever appeared in print.)

So Mike went quiet for a couple of weeks, and then came back with this: a magic wand controlled by his Raspberry Pi. I have been scampering around the study like a schoolgirl since I got his email. He has, as always, written exhaustive instructions if you want to make one yourself, complete with software you can edit on your Raspberry Pi, tips on font design, and notes about the legality of mercury switches (which, as it turns out, are still available and can be used legally as long as you’re not going to sell your magic wand).

Of course, these days, we’re probably supposed to call this a persistance of vision project. But as far as I’m concerned, it’s still a magic wand. Thanks so much, Mike; this is quite a lot like having a rock star you worshipped as a kid re-write a song for you. And I’m sorry about the beating your shoulder took during testing.

A housekeeping note: I’m away for a couple of days travelling to and setting up for DEF CON 20 in Las Vegas, which we’ll be attending as vendors. Bugger. Unforeseen circumstances and all that; we are no longer attending, because a problem with liability for Nevada sales tax came up at the last minute. Really sorry if you were hoping to see us.