A simple, low cost, three-octave frequency gen- erating system, using two passive buzzers and thirty-six touch capacitive switches, implemented with FPGA and VHDL, suitable for hands-on practice of music beginners

Abstract: A frequency generating system, capable of producing 36 different sound frequencies, corresponding to tones and semitones of 3rd, 4th and 5th music octaves, is manufactured, programmed and presented here. The system uses two passive buzzers from which the left one is programmed to produce 3rd octave sound frequencies, while the right buzzer produces middle 4th and 5th octave sound frequencies. Our system also uses two external LEDs related to cor- responding buzzers and each LED lights up if signal is sent to its relative buzzer. An additional information is given to system user by the VHDL program, showing in FPGA board’s seven-segment displays, letters FA or SOL correspond- ing to FA or SOL keys, if left or right buzzer, respectively, is activated. Both FA and SOL are shown in case that user plays a chord from 3rd – 4th or 3rd – 5th octaves. The system is implemented using DE10-Lite FPGA board and 36 touch-capacitive switches, acting as inputs to the board and obviously related to corresponding notes frequencies. Our system has low manufacturing cost and it is ideal for use in hands-on practicing method of music beginners or in any other application where specific acoustic music notes sounds are needed. The VHDL program used here, also provides the ability of expanding our system by incorporating 36 instead of 2 different output buzzers, each one corresponding to specific tone or semitone notes of the three octaves mentioned above. Our system’s capabilities can also be expanded due to the flexibility of the VHDL code, by programming it to generate frequency sounds corresponding to quarter tones.

Keywords: Octaves, music notes, acoustic frequency generator FPGA, VHDL, Buzzer, LEDs.