Waldorf KB 37 User Manual - page 17
10
SENSORS
9.6
Panic
• a wheel’s value reaches its limit way to early
Checking the wheels’ values should be done by looking at the generated MIDI
messages.
To perform the calibration, perform the following steps:
• Press the key labeled Calibrate Wheels while holding the Setup button
• The two outer Octave LEDs will blink
• Release the Setup button
• Move both wheels across their full mechanical range
• Store the calibration data by pressing Setup and the Calibrate Wheels key
again
• The two inner Octave LEDs will flash once to indicate that the calibration
was stored
Hint:
You can cancel the process by pressing any other key on the keyboard
before proceeding the final save operation. This is useful when you accidentally
run into calibration mode.
Note: For safety, the calibration will only be performed when the wheels’
movement covers a minimal range.
Note: There is a small dead zone at the margin of both wheels as well as at
the center of the pitch wheel. This is intentional as it garantees stability of the
control voltages when the wheels are at their extreme positions and prevents
accidental generation of MIDI messages.
Note: The calibration is stored separately from the configuration parameters
and not affected when performing a factory reset.
9.6
Panic
The panic function allows you to send an All Notes Off message to the CV/Gate
interface and all MIDI ports to cut off hanging notes. This can be very useful
when performing live.
10
Sensors
The KB37 features a Sensor input on the back panel that can be used to at-
tach analog control devices. In the simplest case, you can plug in an expres-
sion pedal. By utilizing the learn function, the range of the input signal is then
mapped to the full modular signal level at the Sensor output of the CV panel.
10.1
Learn Function
The principle of operation of the learn function is quite simple: it samples the
signal levels on the tip and the ring of the jack twice. The first measurement is
taken when you press the Sensor button and the second one when you release
it again. Afterwards it takes either the tip or the ring signal, depending where a
larger voltage difference was detected. The measured range is then scaled to
the full 0..5V output range for use with your modules.
Example: learning an expression pedal:
• Move the pedal to its minimum position
• Press and hold the Sensor button
• Move the pedal to its maximum position
• Release the Sensor button
Note: To avoid accidental operation and noisy output signals, the learn function
uses an internal threshold for a minimal signal change. If learning a sensor
doesn’t work, it probably does not provide enough level variation.
10.2
Internal Wiring
The sensor input uses resistor dividers to attenuate 0..5V input signals down to
the 3.3V range of the analog-to-digital converters. Additionally there is a pullup
resistor on the tip input line that makes it possible to power passive components
like pedals and other low-consumption circuitry.
Ignoring some protection elements, this is what it basically looks like:
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