Turn Signal Biking Jacket

This jacket has 2 led arrows on its back that flash whenever a biker intends to make a turn (much like on a car). It uses the Arduino LilyPad, a sewable and washable micro controller, and conductive thread to control the circuit.


Daria T

Area of Interest



St. Ignatius College Preparatory


Incoming Senior

Final Milestone

My final milestone is sewing the LED circuit onto the jacket using conductive thread. The sewing was difficult, because the jacket has two layers of fabric. Since conductive thread cannot be sewn using a sewing machine, I had to be really careful not to overlap any stitches, which would cause a short. The greatest challenge I faced when finishing the jacket was, in fact, electric shorts. I realized that the the knots I was tying at the end of my thread (located at each LilyPad pin) were too large, and were touching each other. I used a multimeter to identify which exact stitches were causing shorts and then redid any necessary sewing.

First Milestone

My first milestone is completing the LED circuit using sewable LED lights, push buttons, the Arduino LilyPad, and alligator clips. The Arduino Lilypad is a sewable and washable version of the Arduino Uno board. In the process of achieving my first milestone, I had to learn how to code the Lilypad. The hardest part was altering my code to deal with bouncy buttons (if you held the button down too long, the lights would not turn off). Ultimately, I ended up adding a 4ms delay in each push button reading, so that regardless how long you press the button, the lights flash the same.

Future Modifications

Although this jacket is safely wearable on the road, it is far from perfect, and in the near future I hope to make another (more improved) version.

I realized that using a lower quality zip up hoodie is best for the project. The thread goes easily through the fabric and is visible to the eye. There is also less chances of running a short.

I also hope to add a break light to the jacket, that is controlled by a speedometer. The challenge to this would be finding a way to attach the speedometer to the jacket using conductive thread.

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