Eowave Eobody2 USB8 SensorBox - Manual (Page 15)

status
on/off
The status field indicates whether the signal on an analogue input should be converted
into a digital message or not. This field may be set to ON or OFF. If the field is set to OFF,
the input is said to be inactive and no message relating to that input will be generated,
even if a signal does physically enter the device. If the field is switched back to ON, the
input is active and its associated message will be sent each time the signal connected to
that input varies in level.
Note:The smaller the number of active inputs is, the less data will be transmitted avoiding
processor computation.
analogue zoom
“analogue zoom” controls the internal PGA (Programmable Gain Amplifier).
1-8 gives a factor of 1 - 32 amplification. The use of analogue zooming will keep the full
bit depth of 4095 values.
digital zoom and offset
digital zoom: max/mid/low/off on 7
offset: -127 to +127
USB 8 sensor interface / Parameter window
0
127
127
Digital value
(12 bits) MIDI data
(7 bits)
MIDI conversion
zoom setting
=
real sensor range
Offset
-127--
Want to stay in the 7-bit MIDI world...
Those two parameters (digital zoom and offset)
specify how the real range of an analogue input
can be mapped on a 7-bit MIDI value. As a mat-
ter of fact, a sensor does not necessarily have
a range equal to the reference voltage of the
Analogue to Digital Converter. A custom scaled
zoom has been implemented on the digital value
to take advantage of the 12-bit resolution of the
A/D converter. First, the voltage reference has to
be set to the largest range among the sensors
connected to the unit. Then, the user can select
the sensor’s range within the 12 bits dynamic
by specifying a window size and an offset. The
selected range can then be converted into 7 bits
MIDI data without greatly increasing the quantifi-
cation step, as shown in the illustration.
The digital zoom & offset parameters may be
very useful to modulate a filter on a certain part
of the amplitude.