The flashing LEDs look great on a hat, and they're easy to add with just a little adhesive. The quickest way is just to wrap the lights around the crown and secure the Gemma and battery holder to the brim.
To attach the Gemma to the hat, use adhesive dots or peel-and-stick Velcro dots. You may need to stack a few so the adhesive is higher than the screws holding the wires.
If you want to hide the excess wires inside the hat, mark two small holes on either side of where you want to place the Gemma LED. Leave enough room so the wires don't have to bend straight down, to avoid straining and possibly breaking them.
Then carefully cut a slit for the light wire. (A ceramic craft knife is safe enough for kids to do this themselves, with adult help.) Thread the end of the light wire through the slit.
For the battery pack wire, cut a small flap to fit the JST plug through. Press the flap closed around the wires when you're done.
Then mark where you want the lights to come out, and cut a slit where the crown meets the brim. Bring the light wire out through that hole and wrap it around the hat.
Finally, attach the battery pack to the top of the hat. (Tape will work temporarily, but for permanent use, put adhesive under the battery pack so you can open it to replace the batteries.)
The Flashing LED Strand can be used in all kinds of wearables and non-wearable projects! You can use it as a substitute for Circuit Playground Express in projects like these:
To use it with the Light-Up Mask project, bunch up the strand of light and press it flat so it fits in the pouch. You can also slip the Gemma into the pouch, if you program the light pattern to run continuously (so you don't have to touch your face). Thread an extension cable from the Gemma to the battery pack through the mask, so you can carry the batteries in a pocket.
- Add it to non-programmable LED strand projects, like the Twinkly Earwarmer Headband.
- Build them into a Halloween decoration, like the CPX Glowing Disembodied Hand.
- Make a separate wristband controller to hold the Gemma and battery pack, using the same technique as for the headband. Then use extra-long alligator wires to connect the lights to the controller. On a light-up jacket, for example, you can run the wires down the inside of your sleeve.
- The most secure way to attach the LED strand is by sewing it on. Find instructions in the Twinkly Earwarmer Headband project.
- To hold the light strand on without sewing, you can try peel-and-stick adhesive dots or fabric fuse in sheets or tape.
- For a more permanent attachment, try fabric glue or even puffy paint.
Experiment! The Gemma M0 and LED Light Strand are inexpensive and versatile enough to test out in a wide ranges of projects -- and they look great!