This project involves the design and implementation of a self-playing ukulele. The ukulele plays chords and plucks open strings based on a song or chord progression selected by the user. Each string on the ukulele has a designated hobby servo motor that plucks the string with pre-programmed timing as is shown in Figure 1 (3). The plucking is achieved by attaching a flexible piece of cardboard to the shaft of the servo to act as the guitar pick. By moving the motors together at once, the action of strumming can be approximated. The design uses the last three frets on the ukulele for pressing different strings and allows the ukulele to play different notes and chords. The strings are pressed by small push/pull solenoids (2) that are spring loaded to push the string when active and not touch the string when passive. The output of the system is controlled with user selection buttons that selects song or tuning mode for the ukulele from an LCD display (6). The user can either select tuning or song playing mode using three pushbuttons. In tuning mode, a speaker plays the desired note for a string and the LCD display prompts the user to pluck that string. The frequency of the note is detected from a microphone and the display tells the user if the string is tuned, too high, or too low.
Davison, Timothy F.; Gonzalez, Arsenio; and Piske, Taylor, "Mechalele (Self-Playing Ukulele)" (2016). Mechatronics Final Projects. Paper 4.