Here is a quick look at what is inside the Build Your Music Self-Playing Robotic Xylophone:
The whole xylophone assembly is enclosed by a box constructed out of Red Oak project boards and plywood. The box is stained with the Red Oak color and finished with polyurethane. A plexiglass window allows one to see the xylophone as it is playing. The window can slide open or closed, in order to make the sound louder or softer.
On the inside, is the xylophone, a Trophy 25-note (2-octave) bell set, with one mallet for each note. Each mallet is attached to a 12V-1A Open Frame Solenoid. The mallets are made out of 3/8″ wood dowels, with 3/4″ round dowel caps coated in Plasti-Dip.
Multiple Adruino Unos control the xylophone. L293D Motor Diver Shields, mounted on “Slave” Arduino Unos are used to fire the solenoids. The “Master” Arduino Uno controls the “Slave” Arduino Uno’s via Serial. An SD Card and Data Logger Shield are used to store all of the song data as MIDI Files. A KY-090 Rotary Encoder and 20×4 Character LCD with I2C are the user-interface, allowing one to select a song from the list of songs that have been loaded.
The code that runs the xylophone was developed with the Aduino IDE. (Actually, I used Microsoft Visual Studio with the VisualMicro plug-in, but the code is exactly the same.) The Arduino source code is available for free download on Github.
Next: Meet the Inventor