Building a Laser Harp
Friday, April 12, 2019, 3:00 PM | Room 7
For my capstone project, I am constructing a laser harp. A laser harp is a MIDI controller, similar to a keyboard. It does not create sound, but like a digital keyboard, has a bank of downloaded sounds that can be played. It differs from a keyboard in how it detects when a note is to be played. Instead of buttons, a laser harp creates a fan of laser beams, and detects if any of the beams have been broken. To achieve this, a single laser is shone onto a mirror that it attached to a motor. The motor rapidly changes its rotation, which in turn reflects the laser beam at many different angles. Even though only one beam reflection exists at a time, because the motor moves so rapidly, all of the beams appear to exist at once, creating a fan of lasers. The harp contains a light sensor at its base. When one of the beams is broken by the players hand, the light is reflected back towards the sensor. The sensor sends a signal to the harp’s microcontroller, which analyzes the rotation angle that the motor is at. By analyzing what position the motor is at, the microcontroller can identify which beam was broken, since the motor’s angle directly affects where the beam is reflected. In addition to building the harp, I will write a paper outlining the entire project. The first part will be research-oriented. I will discuss the physics that allow the concept to work. I will also provide an in-depth analysis into the technical details of the design. The second part will chronicle the process I went through in building the harp. I will go through the steps I took to build the harp, from planning through prototyping to debugging the final product. I will then discuss how I made the design my own. I will detail the extensive changes that I made going from the original design that I found online into the final design that I created. Finally, I will analyze how this project shows the modern value of music in an age of technology, science, and engineering.