Easy
PIC
for dsPIC30
®
v7
page 26
Touch panel controller
Enabling Touch panel
Correctly placing the touch panel cable into the connector
Touch panel is a glass panel whose surface is covered
with two layers of resistive material. When the screen
is pressed, the outer layer is pushed onto the inner layer
and appropriate controllers can measure that pressure
and pinpoint its location. This is how touch panels can
be used as an input devices. EasyPIC
™
v7 for dsPIC30
®
is equipped with touch panel controller and connector for
4-wire resistive touch panels. It can very accurately
register pressure at a specific point, representing the touch
coordinates in the form of analog voltages, which can then
be easily converted to X and Y values. Touch panel comes as
a part of display.
Figure 13-1: Put Touch Panel flat cable in
the connector
Figure 13-2: Use a tip of your finger
to push it inside
Figure 13-3: Now place GLCD with
Touch panel into GLCD socket
1
2
3
Figure 13-5: Turn on switches
5 through 8 on SW11 to
enable Touch panel controller
Touch panel is enabled using SW11.5,
SW11.6, SW11.7 and SW11.8 switches.
They connect BOTTOM (READ-X) and
LEFT (READ-Y) lines of the touch panel
with RB8 and RB9 analog inputs, and
DRIVEA and DRIVEB with RC13 and RC14
digital outputs on microcontroller sockets.
Make sure to disconnect other peripherals,
LEDs and additional pull-up or pull-down
resistors from the interface lines in order
not to interfere with signal/data integrity.
1
2
3
4
5
6
7
8
O
N
SW11
DRIVEA
DRIVEB
LEFT
BOTTOM
READ-Y
READ-X
RB8
RB9
RC13
RC14
Q7
BC856
Q8
BC846
R26
10K
R25
1K
VCC-BRD
R27
10K
R32
1K
VCC-BRD
Q9
BC856
VCC-BRD
R33
10K
Q10
BC846
R35
10K
C40
100nF
R34
100K
Q11
BC846
R41
10K
C42
100nF
R40
100K
R39
1K
VCC-BRD
RIGHT
TOP
LEFT
BOTTOM
E5
10uF
VCC-BRD
C
S1
C
S2
G
N
D
Vc
c
Vo
R
S
R
/W
D
1
D
2
D
3
D
4
D
5
D
6
D
7
E
D
0
R
ST
Ve
e
LE
D
+
LE
D
-
1
20
21
22
23
24
CN20
R
IG
H
T
TO
P
LE
FT
BO
TT
O
M
DATA BUS
Figure 13-4: Touch
Panel controller
and connection
schematics
displa
ys
