These days technology is becoming more and more integrated into our lives. I'm not talking about smart phones, or wi-fi hot spots. I'm talking about seamless integration into our daily lives in ways we don't even notice. One of those ways is through the use of conductive fabrics and threads. Also known as soft circuitry.
One of the ways I get my middle school students interested in technology is by showing them some of the ways that technology is used for fashion. Videos and pictures are nice and all, but I wanted to make something real that the students could see and touch. I've made several little soft circuit "wearables" to show my class, but I wanted something with a bit more... edgy. Or at least some middle school edgy.
One night I came up with this crazy idea to make some earrings. Why, I don't know. It's not like I wear them or anything. I was just looking at some little round perf boards when it occurred to me that they'd be awesome as earrings, and the larger ones as necklaces. Something a bit cyber punk in nature.
And in case you were wondering, that is how I (of all people) came up with this simple design for some LED Earrings.
(Also this is an entry for the instructables 2012 LED contest. You should totally vote for us so we can have a light switch rave in our basement.)
Step 1: What You'll Need
Overall this project requires very small amounts of building skills, and a very small budget. Most of these parts can easily be substituted with something else, or easily changed around.
Small Circuit Board/ Perf Board (eBay, one inch across)
3mm Diffused LEDs
CR2032 Battery Holder (Surface mount with rounded sides works very well!)
Magnet Wire (Thin and small is good)
Earring Clasp of your choice
Needle Nose Pliers
Helping Hand (optional, but helpful)
Total Cost: > $10
For the most part you can find the electronics parts easily on eBay, or even salvage them from somewhere else. The earrings parts can be gotten from any craft store (Hobby Lobby, Michael's).
We have a bunch of parts left over from when we did this (many months ago). If anyone would like me to make a Kit with all the parts in it we can. (We run a little hobby website BrownDogGadgets.com, though we mostly deal with solar kits and projects. Educational and whatnot.)
Step 2: Ideas on Making
The general idea here is that we're going to hook up an LED directly to a CR2032 battery. While this makes the circuit very very simple, it also probably isn't the most effective way of doing this. If we were being very very very safe we'd throw in a resistor.
The nice thing is that a CR2032 Battery is only 3V, whereas a white or blue LED operates at 3.6V. So we're really under voltage, which means we really don't have to worry much. (Yes, we are cutting the life of the red LED a bit shorter. Sue me.)
To turn these on and off, just take the battery out. There really isn't room for a switch.
If you want to go crazy, find some color changing LEDs. They just slowly fade from color to color, and have a cool look.
I've gone with 3mm LEDs because of their size. You could easily use surface mount LEDs (if you're a crazy soldering person) or some larger 5mm LEDs. I just found that a single 3mm LED looks nice without going crazy.
Now you also could sand down the LED if you think it's sticking out too much. Or add on some random electronic parts for looks. It depends on how punk rock you wish to be.
Step 3: Twist the LED Into Place
I've put my LED on the very bottom of my rounded board. You can put it anywhere.
Stick the LED legs through. The bend them in opposite directions.
Remember, the shorter leg is the negative leg. The long leg is the positive leg. This will come in handy later.
Step 4: Magnet Wire
Take your magnet wire and cut a couple of small strings off.
Wrap a piece of magnet wire around each of the legs.
Feel free to tie any knot you want. Or not at all.
Step 5: Solder
Now you need to solder.
Notice what a horrible job I did at soldering. You should probably do better.
It's helpful to have the magnet wire down towards the base of the LED, but so so close that it's touching the other wire.
Magnet wire is coated with a layer of enamel in order to insulate it. Usually soldering will cause this to melt off. If you're running into problems later on, you might not have melted it off. One option is to use some scissors to scrape off a bit before soldering.
Step 6: Wire Up the Battery Holder
Now comes the only tricky part, wiring up the battery holder.
Remember how I said you should take note of the positive and negative legs of the LED? This is why. Somewhere on your battery holder there is a + and a - symbol. Match those up with the proper LED leg.
All you have to do is wrap the magnet wire around the little solder tabs on the battery holder. Which is easier said than done. If you're having issues, use a Helping Hand type device to line the two up.
Be aware that the battery holder is plastic and can/ will melt if you apply too much heat for too long.
Step 7: Test It Out
Before you think of gluing that battery pack in place, now would be a good time to test it out.
Just pop a battery in and see if the LED shines. If not, you probably have the positive and negative legs messed up.
Or your battery is dead.
Or you're being punished by an angry spirit you released from a hidden passageway in the house you broke into with your friends on that field trip to Vermont back in 7th grade right before summer vacation. Or not.
If it works, just throw some hot glue down, or some double sided tape, or a dab of elmers, or super glue, or whatever it is that you want to use.
Step 8: Add on a Clasp
Now that the circuit is done, you should add on a clasp. As I am not a person who wears earrings I am not insanely familiar with the different types of clasps and hooks involves.
When I made my two pairs I used some standard hooks as well as some clip ons.
The big thing here is using some needle nosed pliers in order to bend the little rings into place. It's not tough, just a bit awkward depending on your hand size.
Step 9: Go Wear Them
Thats all it takes actually. If the LED turns on, you're golden.
The round circuit boards I uses were nearly the EXACT same size as the battery holders. While you can't see what they are, you can see them a bit. If you want to completely hide the battery holder you'll need a bigger board.
You may also wish to cover the battery with some black electrical tape. It is very shiny compared to the rest of the earring.
The nice thing is that because you're going to have to buy things in multiples, you can make several of these in different colors. Or sell them. Or something to that effect.