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Pitch bend polyphonic aftertouch, Program change message – Eowave Eobody1 User Manual

Page 17

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This message allows an analogue signal to generate a MIDI message
of the pitch change type (pitch bend). Pitch is usually coded over 14
bits. If the 7 bits resolution is chosen, they will be mapped on the 7
most significant bits of pitch information controlled by the analogue
signal. However, since

eo•body does 10 bits conversions internally,

the whole 10 bits can be mapped to take better advantage of the pitch
bend message. This message is used to simulate the pitch changing
wheels available on most MIDI keyboards.

This message allows an analogue signal to genera-
te a polyphonic pressure type MIDI message (poly-

phonic aftertouch). The number of the note to which the pressure
information is applied can be changed by the user.

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manual ©eowave/Ircam 2003

user’s manual

IV.5. - Use

eo•body Editor

The analogue signal must correspond to an envelope chan-
ging with time and which has a maximum value. You will

have to specify 3 parameters, note sent, higher treshhold, lower tresh-
hold.

eo•body analyses this envelope: once the envelope has reached

the higher treshhold, a MIDI note on message (NOTE ON) is generated.
The velocity associated with the note is fixed to 127. The note number
contained within the message is adjustable by the user. As long as the
envelope stays above a threshold, named NOTE OFF threshold, the
note is maintained (no new MIDI message is sent). When the level falls
beneath the NOTE OFF threshold, a MIDI NOTE OFF message is sent
to turn the note off. To sustain the note for a long period of time, you
just need to give a small value to the NOTE OFF threshold. Conversely,
to make the note stop shortly after the peak has been detected, you
need to set the NOTE OFF value quite large. This type of message is
useful in using sensors to generate MIDI notes.

Note on message

Signal

t

NOTE ON message

NOTE OFF message

NOTE ON

threshold

NOTE OFF

threshold

t

NOTE ON

t

NOTE OFF

Pitch bend

Polyphonic Aftertouch

The analogue signal must correspond to an
envelope changing with time and which has a

maximum value. You will have to specify 3 parameters, Program
Change sent, higher treshhold, lower treshold.

eo•body analyses this

envelope: once the envelope has reached the higher threshold, a MIDI
Program Change message is generated. The Program Change contai-
ned within the message is adjustable by the user. As long as the enve-
lope stays above a threshold, named lower threshold, the Program
Change is maintained (no new MIDI message is sent). When the level
falls beneath the lower threshold, the

eo•body is ready to receive a

new Program Change message.

Program Change message

N-ON trigger

PC

PB

ATp