Process

I started by thinking about how to detect the user's heartbeat effectively. Based on my experience, it is best to place the sensor around the wearer's neck, so I chose a high-neck shirt to work with. The high-neck collar covers the sensor and makes sure it is touching wearer's skin.

I came up with two designs of LED lights. The first one uses the parallel curcuit structure we learned and practiced in class. The second one uses LED strips. I think the second design is easier and more straightforward to work with. There are multiple kinds of LED strips out there, including color-changing strips and water-proof strips. I want the strips to change colors according to wear's mood. For example, the lights will turn to red and start to flash when the wearer is nervous. 

The most challenging part is to find a way to control the lights. I used Arduino and a computer to  analyze heartbeat sensor's data last time, but it is impossible to use a computer this time. I found some kind of remote control for LED lights that works pretty well on wearables (http://www.instructables.com/id/Glow-like-the-sun-with-this-sound-reactive-LED-cyb/).