Default values are set for Emerald Development Kit V1.0 with default 95x60 mm Electrode (4-layer/1.5
mm PCB).
•
Electrode X Distance
corresponds to the distance between the inner edges of West and East
electrodes.
•
Electrode Y Distance
corresponds to the distance between the inner edges of North and
South electrodes.
3.2.8.2
Electrode Weighting
The Electrode Weighting is an optional step to adjust parameters for position tracking. Five
measurements with the artificial hand and five reference measurements without it are conducted at a
constant height of 30 mm. Always use the 30-mm Styrofoam spacer to establish the height. The drawing
in the Electrode Weighting step will show the correct placement of the artificial hand for each
measurement (West, North, East, South and Center).
The
Start Measurement
button will trigger the measurement. After pressing the button, a bar will show
the progress of the measurement.
The reference needs to be measured within the next 10s to avoid influences from signal drifts. A down
counter is displayed in the Visualization window. If the reference measurement was not acquired during
these 10 seconds, a pop-up window will be displayed. The measurement needs to be repeated.
Removing the artificial hand and pressing the
Start Measurement
button will trigger the reference
measurement. The measurement table displays the signal level with artificial hand (hand brick), without it
(reference) and the difference between them (Delta).
The measurement process checks if the measured data is valid and if the environment is noisy.
When the data is not valid, it is displayed in red in the measurement table. If the variance of the signal
was higher than ten digits during measurements, the noise indicator in the status bar blinks and Aurea
shows a red message reporting that there was noise detected during the last measurement:
"Measurement variance exceeded threshold"
. If the Delta is negative, meaning that the reference level
was higher than the one with artificial hand, a red message will be displayed:
"The Delta is negative"
.
The user has to check the measurement setup and repeat the measurement.
Typical reasons for failed measurements are:
•
User activity in the sensing space while measuring
•
PC not grounded
•
Artificial hand is not grounded
•
Artificial hand is shaking and the setup was not mechanically stable
•
External noise sources (conducted or irradiated)
Once the Electrode Weighting step is finished, press the
OK
button.
It is not necessary to adjust/correct the 30-mm Styrofoam spacer brick for the thickness of the target
device housing or for a decoration layer covering the electrodes.
The collected data corresponds to the Signal Deviation Mean (SDM) of the electrodes signal levels.
3.2.9
E-Field Linearization
The E-Field Linearization is an optional step to adjust parameters for position tracking. Four
measurements with the artificial hand centered with the system and four reference measurements without
it are conducted at different heights (10 mm, 30 mm, 50 mm and 80 mm). Always use a Styrofoam spacer
MGC3140
Tuning
©
2018 Microchip Technology Inc.
User Guide
DS40002055A-page 17
