Guest blog: David Miller – A solar-powered glitter ball rotator

My Dad’s always had an interest in tinkering with electronics and the like. Recently he made an interesting thing so I asked him to write it up, and here it is:

A few weeks ago my wife and I were invited to join four friends for Sunday lunch. Our host has a south-facing dining room with a glitter ball sitting in the window. We were all entertained by the light beams gradually moving around the walls and ceiling. I suggested that a small solar cell and motor attached to the glitterball might improve the entertainment.

I bought these parts from Maplin soon after at a cost of £3.60. I glued the motor and cell to a spare ruler to which I also glued a strong copper wire to attach all to the ceiling. I have this running in our garden room.


It rotates too fast and I need to add a resistor. Whether our friend will want this clutter with her glitter ball I have yet to find out. I await her next visit here before further changes.


Walls Have Eyes goes to the Design Museum

We made this initially as a post for a presentation at work, but it doesn’t seem quite right for a work blogpost (though we will do one for that too) but it seems a shame for it not to be public.

The context is this: a fairly quick hack Andrew Nicolaou, Jasmine Cox and I made for Mozfest got nominated for Design of the Year 2015, and so we redesigned it so that it would last five months in place at the museum as part of their exhibition (we hoped; we’ve had some teething problems).

This was something that’s completely new to me and Andrew, though Jasmine is much more experienced at making these kinds of things.

This is the story of us setting it all up.

Jasmine took most of the photos.

As Andrew pointed out, it’s come out a bit like a Peter and Jane book.

We initially made Walls Have Eyes very quickly as part of Ian and Jasmine’s Ethical Dilemma Cafe

The combination of electronics in innocuous frames


and an extremely noisy dot matrix printer


and an updating html output from the cameras, meant that it got the message across quite well


Then we were unexpectedly nominated for the Designs of the Year, which meant we had to build something that lasts 5 months.

So we needed to redesign it a bit and improve the code


It was going to be on a wall rather than in an ambient cafe environment, so it needed a trigger, to make the experience more immediate, like this ultrasonic sensor

It needed wired networking rather than wifi for reliability, and we needed to test it intensively


so Andrew and Libby rewrote the code (mostly Andrew).


Andrew designed and laser cut some beautiful glowing fittings for the frames


Andrew, Dan and Libby tested it at QCon, including creating a ‘surveillance owl’ fitting for the sensor


and working through a load of issues


By thursday we had all the bits more or less working in the kitchen


On Friday morning we took it all to the Design Museum, realising in the process that we needed better bags


At the muesum, this was the first time we’d put the Raspberry Pis in the frames


and consequently that took a while



Then placement took even longer


and involved drilling


and pondering


and threading wires through holes


We didn’t quite get it ready by the end of friday and had a mad dash to get trains, punctuated by Libby taking pictures of Tower Bridge


On Monday, Andrew did a very slow, stressful dash across London through the roadworks to pick up some postcards and sort out the networking so we could debug remotely.

Then on Tuesday we all went over to do some final tweaks


and debugging.


Then, finally, the party started.


and it was working!


and people were looking at it!


so we had a small beer.


and it works still…


…although yesterday we had to do a little fix.