Controlling PowerPoint with bananas

Recently I was asked to give a presentation to my 300 or so colleagues at the Herald & Times Group. I’d given a talk to the same audience on pretty much the same subject just a couple of months before, so I felt I needed a bit of a twist to make it interesting.

So… I built a quick PowerPoint clicker out of various pieces of fruit.

Alternative PowerPoint clicker

At the heart of the project is a Makey Makey, a derivative of the Arduino Leonardo which is pre-programmed to trigger certain specific key presses when the circuit to the relevant input is completed.

I only had an hour or so to pull the project together, so a quick trip to the local supermarket on the way to work yielded some fruit and a handy stainless steel meat carving tray, complete with some fairly aggressive welded-on spikes.

The plan was to use different pieces of fruit to trigger each set of slides (I had five topics to cover) but to save time I just hooked all the pieces of fruit up to a common terminal, linked to the primary mouse button.

The ground wire was attached to me – specifically wedged inside my belt against my skin. The circuit was completed by me touching any of the pieces of fruit.

Add a quick fruit-themed PowerPoint deck and I had a pretty fun presentation, brought to the audience by bananas, apples and grapes.

Lessons? The whole thing worked pretty well, but the ground wire on my body was the least reliable part of the project. If I had time I’d have run a longer loop of bare wire and stuck it on with medical tape, but for what it was, it did the job.

There’s a video of another of my Makey Makey projects – a fruit and veg piano – here: