Automated Harmonica

Our team of six designed and built an automated harmonica with a budget of $250. The goal of the project was to spark interest in engineering and showcase fundamental STEM concepts to younger children in a classroom or demonstration environment.


Initial brainstorming led to the sketch shown. It consists of a single harmonica fixed in place with a 3D-printed enclosure. Silicon tubing is friction fit into each hole of the harmonica, and the air is diverted through each tube with solenoid valves. An Arduino takes inputs from a dedicated user interface and controls the valve actuation and indicator LEDs. The air supply is a basic 2-way bike pump and fills a pressure reservoir that holds enough air for the average song.

Initial Sketches



Initial Sketches


Initial ideation led to the sketch shown. It consists of a single harmonica fixed in place with a 3D printed enclosure. Silicon tubing is friction fit into each hole of the harmonica and air is diverted through each tube with solenoid valves. An Arduino takes inputs from a dedicated user interface and controls the valve actuation as well as indicator LEDs. The air supply is a basic 2 way bike pump and fills a pressure reservoir that holds enough air for the average song.


  • Switch to an air compressor with tank and delete air bladder (more powerful, consistent airflow, can play for minutes at a time before needing to charge the compressor back up)

  • Leave space between tubing and harmonica (better sound quality and volume)

  • Use pyFirmata package and the Firmata protocol to offload the computation onto the user’s computer (more flexibility coding in Python, set up for a GUI, packaged as an executable)

  • Graphical User Interface created with the tkinter package (easy to understand and interact with)

  • Laser cut box (easy transport and safety factor)

Pivots

Features

  • Graphical User Interface

    Allows the user to play individual notes or a pre programmed song. Packaged as an executable so anyone can access and use it on their own device.

  • Laser Cut Box

    Mixed material laser cut box houses all of the components for easy transport but does not obstruct the view with dedicated windows and a clear acrylic top.

  • LED Indicators

    LED indicator lights glued onto each valve and light up indicating which valve is being activated.


Catalog

Ode to Joy

Jingle Bells

Mary Had a Little Lamb

Hot Cross Buns