MIDI Controller Using A Trumpet

Overview

The purpose of the project is to convert any standard trumpet into a fully functional MIDI controller and MIDI pass through device for up to 16 channels by combining custom hardware and software with the Yamaha Silent Brass pickup mute.

Details

Trumpet players are allowed the freedom of synthesizing from and composing on their native instrument using the trumpet MIDI controller. The center of the trumpet’s electrical design is the microcontroller board with Atmel ATmega32 running at 16MHz. Its functions include outputting the corresponding MIDI commands, processing the data, and sampling MIDI commands, valve presses, and audio data. Biasing for the BJT within the condenser microphone as well as amplification of the audio signal with an AD623 instrumentation amplifier is provided by the audio board. A resistor voltage divider provides the biasing.

To determine which valves are depressed at a given time, the photodiode board uses pairs of LED. One of the diodes is tied between ground and the base of an NPN BJT where a voltage on the BJT’s base is produced by the incident light upon the photodiode while the other diode is set up to emit with a constant 20mA current.