MIDI Pitch Transposition

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Description:

The MIDI Pitch Transposition unit can be used to shift the pitch of a MIDI note by up to +8 or -7 semitones, on all MIDI channels except Channel 10 ( the drum channel). Also all MIDI Channel commands, Program Change, Control Change, Pitch Bend, Channel Pressure and Polyphonic Key Pressure are passed through unchanged. All MIDI System Realtime messages are filtered out. Note that this unit operates via the MIDI IN and OUT sockets only and not through the USB connection.

Operation:

The unit detects the incoming MIDI data and the MIDI Pitch Transposition unit is then used to shift the pitch of a MIDI note by up to +8 or -7 semitones, on all MIDI channels except Channel 10 ( the drum channel).

Power Supply:

External power can come either from an AC-to-DC adapter or battery. The adapter can be connected by plugging a 2.1mm center-positive plug  into the board's power jack.

The board can operate on an external supply of 7 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.

MIDI Pitch Transposition Selection:

The MIDI Pitch Transposition unit works on all MIDI channels (1-16), except the drum channel 10. So the pitch of all the notes playing are transposed by the same amount. The system will also work with MIDI running status.

 

 

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Features:

The MIDI Pitch Transposition Unit consists of:

• An assembled, built and tested Arduino board including a suitable pre-programmed microcontroller,
• The MIDI Pitch Transposition is user selectable via the 4-way DIP switch
• A 2.1mm power socket, and associated LED,
• A MIDI activity LED,
• An assembled, built and tested MIDI In/Out Board,
• A 150mm wired MIDI 5-pin DIN input socket,
• A 150mm wired MIDI 5-pin DIN output socket,

The MIDI Pitch Transposition Unit requires:

• a 9v battery or equivalent DC power source

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Resources:

The MIDI Pitch Transposition Unit Resources:

• The MIDI IN/OUT circuit schematic is available,
• The MIDI IN/OUT wiring is also available,
• The Arduino Uno Board Schematic is available,
• The Arduino Uno Board Pin Layout is also available,
• MIDI Source Code for the Arduino.

 

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