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I recently made my friend Matthew a suit with hidden LEDs in it. So that his partner, Hannah, wouldn’t be out-blinged, I made her a disco necklace.

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Video demo

I used an Adafruit Gemma (124-5508) and a strip of neopixels. These were powered by a LiPo battery. I made a little velvet bag for the battery and flora.

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Velvet case, hand-sewn 

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Gemma and battery were stuck together and slipped into the velvet case

I used three black wires to power and control the neopixels from the Gemma. I plaited them for a pretty effect. I did the same for the other side, although these were not electrically connected.

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Plaiting the wires 

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Plaited wires made the “chain”  

To make the chain large enough to fit over the head, yet not be too long when worn, I made a very rough closure system. I just left a gap in the non-electrically connected plait and threaded the electrically connected plait through it. Either side of the “gap” I put heat shrink to stop the plait from un-plaiting.

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Closure of the necklace  

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The electrically connected plait went through the other plait 

To make the neopixels and soldered connections a little less “electronicy” I used waxed cotton (that I usually use in leatherwork) and did West Country whipping around the joints and neopixels.

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West Country Whipping around the neopixels, using waxed cotton

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Close up of the west country whipping

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Whipping around the neopixels

Verdict: Cool to look at, but still a bit too heavy to wear for long!

Bonus video

 Parts list

Item Supplier Stock number
Adafruit Gemma RS Components (124-5508)
Neopixel ¼ 60 ring Adafruit 1768
Lithium Ion Polymer Battery – 3.7v 2500mAh Pi Supply -
I am an inventor, engineer, writer and presenter. Other stuff: Royal Academy of Engineering Visiting Professor of Engineering: Creativity and Communication at Brunel University London; Fellow of the Institution of Mechanical Engineers and have a PhD in bubbles; Judge on BBC Robot Wars.
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