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11 LCD PANEL CONNECTION CIRCUIT
S5U1C17801T1100 HARDWARE MANUAL
EPSON
33
(SOFTWARE EVALUATION TOOL FOR S1C17801)
Touch Panel Controller Connection Circuit
The touch panel function is installed in the LCD panel module on the SVT17801. The following shows how the
touch panel is connected to the S1C17801.
V
DD
S1C17801
P33
P34
AIN5
AIN6
6
5
4
1
2
3
U102
74LVC2G14
C110
0.1µF
1Y
VCC
2Y
1A
GND
2A
C109
470P
C108
470P
Q104
UNR5213
Q102
UNR5213
Q101
UNR31A300L
Q103
UNR31A300L
LEFT
TOP
RIGHT
BOTTOM
LCD panel module
(EW32F92FLWP)
VDD
Fig. 11.1.1 Touch Panel Connection Circuit
In the above connection diagram (figure 11.1.1), panels touch position information entered from AIN5/AIN6 is ob-
tained as an AD value while the circuit shown above is controlled by P33/P34 of the S1C17801. The following lists
each signal status of the panel module and the S1C17801.
Table 11.1.1 Function of Touch Panel Control Signal
Pin No. X-axis Y-axis
S1C17801 P33 LOW HIGH
P34
HIGH LOW
AIN5
LOW 0 to VDD(V)
AIN6 0 to V
DD(V) LOW
LCD panel module LEFT HIGH Hi-Z
TOP
Hi-Z HIGH
RIGHT LOW 0 to VDD(V)
BOTTOM 0 to V
DD(V) LOW
In order to obtain panel s touch position information on X-axis of the figure 11.1.2, an AD value obtained from
AIN6 is used to determine the position of X-axis when P33 is turned LOW while P34 HIGH as shown in X-axis
fields shown in the table 11.1.1. (The AIN6 value becomes gradually larger for the left side of the figure 11.1.2.)
On the other hand, to obtain panel s touch position information on the Y-axis of the figure 11.1.2, an AD value ob-
tained from AIN5 is used to determine the position of Y-axis when P33 is turned HIGH while P34 LOW as shown
in Y-axis fields of table 11.1.1. (The AIN6 value becomes gradually larger for the upper side of the figure 11.1.2.)
This principle to obtain X-axis and Y-axis data helps acquire two-dimensional touch position information by obtain-
ing X-axis and Y-axis AD values while alternately switching between P33 and P34 statuses with a short duration.
AIN5 (Voltage HIGH)
AIN5 (Voltage LOW)
Y-
axis
X-axis
AIN6 (Voltage HIGH) AIN6 (Voltage LOW)
SVT17801 LCD BOARD
EPSON
Fig. 11.1.2 Image of X-axis and Y-axis Analog Values of Touch Panel