I’ve been stretching my earlobes over the last few months and this week I finally hit my target of 5mm.. anyone one thats done this (and has an odd sense of humour..) has been through the point where you think “what can i stick through the hole thats strange and wonderful?”

Well I was ordering some parts for another project and started browsing LED’s, sure enough I spot the “5mm ultrabright” section and start thinking “hey that’d work…”. Well I had a 5mm LED already but it was too large, however the 3mm ones fit in the metal tunnels I have perfectly…

So the engineer-lobe of my brain started working overdrive, How can I power it? How can I hide the power source? Can I make it do anything cooler than just stay on all the time?

Half an hour later I’d ordered a load of ATTiny13 controllers, some Lithium batteries and a load of 3mm LED’s. This morning they arrived so I got to work. First step : making the jump from Arduino to proper AVR coding

turns out to be dead easy (at least for simple bits of code), AVR Studio is rather good..

I needed to find thin and flexible wires for the actual LED, the plan being that I hide all of the electronics in my hair (I’ve got a lot of it…) and just have the LED visible through the ear. For this I dismantled an old motor and stole the copper windings, its thin, flexible and insulated Once the insulation is burnt off with a soldering iron it can be used as normal wire.

The straw is to fit over the arm of my glasses and hold the whole thing on my head, it fits perfectly The black tape is temporary until I can get some heatshrink stuff or get a hold of a rapid prototype machine(not likely)

So once I’d got it programmed and working how to get PWM working (dead easy) I started working on the physical layout of it all

The circuit really is too simple, standard LED and resistor combo glued to a CR2032 battery, the GND pin of the ATTiny is bent inward to touch the -ve side of the battery, VCC is connected to some stiff wire leading round to +ve side and the resistor for the LED is glued to the top of it. Solder some thin wires, attach a straw and wrap in electrical tape. Job done.

I thought this looked like an ant..

and theres the first prototype!

Next plan is to get some sensors in there, maybe a thermometer and a bicolour red/blue LED to show temperature, or a microphone and try to pick out beats in the surrounding sounds and flash the light with it. I’m looking at sensing heart-rates with IR led’s as well, that would be rather cool…