Video: Makey Makey slide mover

20180722_130151Ever been frustrated when your slide clicker runs out of batteries? Me too! My Code Club kids, and Pi-Wire pal Chris, have a ‘practical’ solution: use a piano pedal!

There were two versions: the first was ok, but had some flaws. As later figured out, it was a bit unreliable. I was so impressed that the kids developed ideas for version 2, improving it a lot! With a bit of tweaking, the second version was perfect – and all it took was some play doh and a bit of rewiring. Click below to see how we did it…

You’ll need a Makey Makey, a piano pedal (or anything metal – a chair leg will do), some alligator clips, a grounding strap and a willing ‘volunteer’. No electric shocks involved!

At the end of the post, I also talk about using Makey Makey in school. If you liked, please like or retweet!

Also, hairy legs are an insulator – who knew?!*
(* Chris’s, not mine…)

Overview Back button The wiring Grounded glasses

(L-R: overview, the back button, Makey Makey wiring, grounded glasses)
Note the grounding strap around his foot – that’s completing the circuit.

Making your own…

  1. The first thing was to connect our Makey Makey to the piano pedal itself with an alligator wire. The pedal’s metal, so conductive. As we later realised, the three pedals were linked inside, which meant we couldn’t use them as separate buttons. The pedal is connected to the down-arrow terminal.
  2. Once connected, we put a grounding strap on the earth connection, which pianist Chris wore around his ankle. This didn’t work! We realised hairy legs were insulating it, so he slid it down a bit over his foot, and it worked there – probably (hopefully?) not an issue if you’re doing this with kids!
  3. We connected a ‘back’ button (up arrow terminal) to the second piano pedal. Unfortunately, they’re linked inside the piano, so they wouldn’t work as separate conductors. We put a play doh button on the side of the piano instead, and this worked. It’s great with Makey Makey because it’s easily sticks to stuff when you need a push button.
  4. Our first version was unreliable – it worked sometimes, but not others. As well as the linked pedals, we realised Chris wasn’t conductive enough. The kids made their own test table, and figured out it worked much better without socks. Second time around, Chris had one shoe (to insulate him when he used the sustain pedal), and one bare foot (to move the slides on).
  5. One of the kids (his 8 year old) suggested using metal-rimmed glasses as earth. So we tried that in place of the grounding strap – it worked! The rest of the setup was the same (including the pedal).

Media

Click the video to see the play doh back button being used to flick backwards.
Towards the end, Chris also uses the pedal to move the slides on.

Lessons learned

The superficial: so, yeah, hairy legs insulate. It didn’t work reliably first time, and the pedals were linked inside (make sure your conductors aren’t touching).

More seriously: I was amazed how into this the kids got (and frankly, me too!). It was their idea, and the testing/debugging cycle was their own system, and really thorough. They were keen to show it off to others, especially kids who hadn’t been to their Code Club! I’m seriously considering using Makey Makey to revise the SQA’s software development process for my National 4 and National 5 classes this year (if we get time). I reckon we could do a complete project in one double period, taking the project through the whole lifecycle as group work. I’ve already used Makey Makey in school a little, but only to talk about input devices and as a games controller for the NPA Computer Games Development class. The BGE outcomes for Computing Science also have a fair bit of leeway for developing physical computing solutions.

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