The Challenge: Teach a group of tween girls about electronics.

The Response: The BlinkyHat Project

Start with a camp hat, add some lights, some batteries, and a little tiny computer.

Follow the steps to get from a pile of components to a finished project.

Look out for the ATtiny85v code and the PDF of how to do the wiring.

With the support of the think|haus hackerspace in Hamilton, Ontario and specifically Adina Bogert-O'Brien and Trevyn Watson.

Step 1: Materials Required

- bucket hat
- pre-assembled circuit board & battery pack
- 3 AAA batteries
- laser cut battery pack carrier / name plate
- 4 white LEDs
- 4 blue LEDs
- CR2032 3V battery
- 8 straight pins
- sewing needle (that will fit through the holes in the perf board)
- 25' plain poly-cotton thread
- 25' conductive thread
- 2 1-1/2" sections double stick foam tape

Step 2: Prototype #1

Prototyping is important!

Most of the wiring is just moving things around so that it all fits on the one board.

Coin cells are awesome for doing stuff like this midi-breadboard.

Step 3: LEDs

You need to do something with the legs of the LEDs to make them easier to attach.

We'll be doing both a mechanical and an electrical attachment.

What did I tell you about coin cells!

Using pliers, bend the negative leg (the shorter one) into a square-ish shape and the positive leg (longer) into a roundish shape.

Step 4: Laying Out the LEDs

Get the positions of the 8 LEDs in place with straight pins - just pretend you're cutting a pizza into 8 pieces.

Step 5: Attaching the LEDs

Using plain thread, sew the LEDs and the battery pack/perf board to the hat.

It's important that the parts are all held on strongly before we get to the electrical connections.

Step 6: Attaching the Electronics

So the prototype was compressed down to a little piece of perf board and a battery pack.

Step 7: Grounding!

Sewing on the underside of the hat, do long skipping stitches and make sure to wrap the thread 3 times around the metal part of the LED as you stitch past it.

Finish up by bringing the ground wire up the inside of the hat and then through to the ground pin on the controller.

Step 8: One LED at a Time...

Once you've put a few wraps around the LED, slip the needle up the middle of the two layers of the brim of the hat and have it come out at one of the stitched perimeter rings -- we're going to put both LEDs onto a ring of thread - starting from the inside edge of the brim, 1-4

When you get done, test to make sure it works by putting batteries in!

Step 9: Now That's a Nice Hat!

And before you know it, you're done.

Step 10: Well... Not Quite

There's another feature on the controller -- if you close pin 6 to ground using a switch, you reveal the "freaking out" mode of light.

I'm not sure how to implement this exactly.

Yet.