A typical bamboo flute has total of seven holes as shown in the picture. One of these holes is for the inlet of wind. The strength of air blown into this hole determines the octave of the note. The greater strength wind play the higher octave note and the lesser strength wind would play same note from lower octave. The other six holes need to be covered with the fingers in order to play different notes. The portion of the holes covered also matters in generating sounds. For example, if a fully covered hole generates a note at C scale, the half open hole can generate a C minor. To mimic the typical bamboo flute, our electronic flute was designed with 12 Charge Time Measure Unit (CTMU) to simulate the sounds with whole covered or half covered holes in bamboo flute. To adjust the octave, one microphone and one CTMU were implemented on our electronic flute.
Basic Logical Structure
The sensing for the capacitance touch switch will be done using CTMU in PIC32 controller. The high octave was produced using the on chip PIC32’s ADC unit connected to the microphone. The low octave was generated using CTMU which mounted at where the player’s mouth can touch while playing the flute. The sound signal will be sent to DAC via SPI and output of DAC will be supplied to the Speakers or headphones. The user is able to select different scales based on two buttons and visualize the scale selection feedback given by TFT LCD.
Hardware and Software Trade-Offs
The primary motive of the project is to synthesize signals in PIC32 in order to generate the sounds which are as close as to a real flute as possible. In order to maintain our primary goal, the team should spend more time on sound synthesis section. Considering the flute should be convenient to play, the weight of the flute should keep small. Therefore, the speaker and power supply(battery) cannot be put on the flute.
The multi-scale electronic flute mimics the real flute playing. Unlike the traditional flute using the air flow generating sound, our multi-scale electronic flute uses the software program to generate the flute sound based on the sound frequency. Considering the issue that the traditional flute cannot generate a very loud sound, our multi-scale electronic flute connected with speakers that can amplify the sound. Also, it can connect with headphones to support practicing flute playing individually.
Rhino resonator and flute crown is a patented flute optimization design. This technology improves sound generation, amplified and stabilize the flute sound. However, our multi-scale electronic flute considered more than amplifying flute sound. The electronic flute can also support up to eleven different scales of operation. In this case, the flute players can use one multi-scale electronic flute instead of needing eleven different flutes for each scales.
In addition to that, the TFT display was mounted on the side of the flute showing the player the scales that the player is currently playing. This new design method is rare in electronic flute market.