Figure 3-9. Approach Detection Height Against Sensitivity
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0
20
40
60
80
100
D
et
ec
tio
n
H
ei
gh
t
as
p
er
ce
nt
ag
e
of
de
te
ct
io
n
ra
ng
e
Sensitivity
Height as % of
detection range
The Sensitivity slider 1 selects how much signal change is necessary to wake up the system. The value
can be adjusted in the range from 1 to 100; default is 76.
•
High values will lead to a sensitive wake-up behavior. This means that small signal changes are
enough to wake up the system. This results in higher detection range in the Self Wake-up mode,
but may also lead to unintended wake-ups due to increased noise levels.
•
Low values will lead to a less sensitive wake-up behavior. This means that higher signal changes
are necessary to wake up the system. This results in smaller detection range in the Self Wake-up
mode but, at the same time, the system will be less prone to unwanted wake-ups in case of
increased noise levels.
3.2.7
Touch Detection
The Touch Threshold North, East, South, West, Center fields specify the SD values that have to be
exceeded to validate the touch event. The range is 0 to 32768. The horizontal darker line in the Level
window is adjusted according to the slider value.
•
Touch each electrode in its geometric center and move the finger to the borders of the electrode
while touching.
•
Adjust corresponding Touch Threshold 1 according to the displayed SD value while the finger is
positioned on the electrode. If touches are missed, the Touch Threshold might be needed to be
decreased.
Note:
The values in the Level window are shown in log scale.
The touched state is exited if the SD value drops below the Release Threshold. This threshold (horizontal
lighter line in the Level window) is an adjustable percentage of the Touch Threshold. The percentage of
the Touch Detection Threshold can be adjusted between 50% and 100%. To adjust it, proceed as follows:
•
Touch each electrode in its geometric center and change the hand posture. If Touch state becomes
released although the user is still touching, the Release Threshold needs to be decreased.
MGC3140
Tuning
©
2018 Microchip Technology Inc.
User Guide
DS40002055A-page 15
