In science I learned about circuits, electricity, resistors and batteries. So back at Hallowe’en, my mom and I tried to make an electronic wearable drum kit. We went out to an electronic store and bought some of things like the LilyPad MP3, and some piezo electrics, as this was part of an electronic science project. We tried to make the costume like this one, but it didn’t work because when I hit the piezo it took a few seconds to play the song. So before Christmas I was brainstorming ideas for ways we could use all the electronics stuff and, I came up with the idea to make a Christmas sweater. So to celebrate the Christmas spirit we made a Christmas sweater that when you move the bird to touch the star, Christmas music will start playing and you can adjust the volume with the zipper!
Materials:
- A long sleeve sweatshirt/sweater
- Fabric for sewing on a Christmas design
- 5 resistors
- Pixie lights
- Arduino LilyPad MP3 player
- A speaker that connects through a headphone jack
- Conductive thread
- Metal zipper
- Wires
- Battery pack to connect to Arduino
Arduino and Circuit Boards
Arduino is an open source hardware and software company that designs easy to use electronic platforms. They make different types of circuit boards, which is basically a mini computer that is programmed to listen to different inputs and decide how to change them into outputs. The LilyPad MP3 is the simple circuit board that we used. It has lots of different parts to it. There are 4 speaker outputs, so you can have 2 speakers connected, and there is one headphone jack. Then there is a spot where you can plug in a battery pack. Some other parts on the board include, micro SD card socket, microchip, resistors and a few input ports.
Start
My first step was to lay out the design I wanted for my sweater. I cut out fabric for the tree, and decided where everything should go. I decided to put the Christmas tree in the middle of the sweater and hide the Arduino under it. Then I would sew a strip of white fabric to the bottom of the sweater, so it would look like snow.
Volume Control
Then what we had to do was figure out how to make the zipper change the volume. We got the idea from a video we watched earlier. This way when the metal zipper would make contact with the conductive thread the circuit would go through the resistors above. I suggest using a zipper that has metal teeth. In the end ours worked, as the slider was metal, but the teeth weren’t metal so when the slider was in between resistors the current would go back to the full resistance. And it was hard to get the conductive threads to touch through the slider. I then sewed the resistors onto the fabric of one side of the zipper, and I connected each of them with conductive thread. Then on the other side I just sewed in a line from the bottom to the top.
Coding the Arduino
Coding the Arduino was probably the most time consuming part. I’m not a coder, so I worked on the design of the sweater while my mom did the coding. (She tried to explain it to me, but I did not understand.) What I do understand is that we had to put a code on the Arduino so that when we open the zipper the volume would get quieter.
The Speaker
To play music/Christmas songs out loud we had a small speaker to connect to the Arduino. Our biggest challenge was when we somehow broke the amp on the LilyPad. So we couldn’t use the small speaker we had bought at the electronic store. Instead I had to use a giant speaker that plugs in through the headphone jack. It worked fine, but it just meant that I would have to carry it around with me while wearing the sweater.
Play button
We were going to use piezo electric buttons to play the music, but our piezos weren’t working, so instead we did a simple contact. I connected the conductive thread coming from the Arduino, to the start at the top of the tree. I looped the thread through the star enough times so that the thread would work in a circuit by touching. Then coming from the ground setting on the Arduino, I got some wires to go under the sweater, and out father up on the sweater. And that’s where we hung the bird from. So when the birds nose touches the middle of the star the circuit will connect and the music will start playing.
Sewing
Once we had an idea of where everything should go, and how it would work, I got to do my favourite part…putting it all together. I started by sewing the tree to the middle of the sweater, leaving enough space on one side, so the Arduino would fit in.
Then I made the first half of the simple contact, which was a start on top of the tree. I connected the wire coming under the tree, to the T1 setting. To set up the zipper we had it sewn on near the top left shoulder, then we connected the conductive thread bringing it though a small hole we cut in the shirt and connecting it to the Arduino’s ground and T2 settings. Next I set up the bird by cutting a hole in the shirt and putting the wire coming from ground, through, and I hung a bird further up. As an add on, I put snow on the bottom, and snowflakes to hide the hole from the bird. The pixie lights were also an add on, originally we were going to connect them to the Arduino, but ran out of time.
Even though there were lots of challenges, this Arduino project was very exciting and satisfying when it turned out. Overall it was a fun project, definitely beats reading out of a textbook!