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