Development of a portable automated piano player CantaPlayer

This paper describes the development of a low cost, compact and portable automated piano player CantaPlayer. The system accepts digital MIDI (Musical Instrument Digital Interface) files as input and develops pushing actions against piano keys which in turn produces sounds of notes. CantaPlayer uses Pure Data, an audio processing software to parse MIDI files and serve as user interfaces. The parsed information will be sent to Arduino, an open source microcontroller platform, via serial communication. The Arduino I/O pins will be triggered based on the information from Pure Data of which connected transistors will be activated, acting as a switch to draw in larger power supply to power the solenoids. The solenoids will then push the respective piano keys and produce music. The performance of CantaPlayer is evaluated by examining the synchronousness of the note playing sequence for a source MIDI and the corresponding reproduced MIDI. Three types of MIDI playing sequence (scale, polyphonic and rapid note switching) were tested and the results were satisfactory.