Touchpanel controller
Enabling Touch panel
Correctly placing the touchpanel cable into the connector
Touchpanel 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 touchpanels can be
used as an input devices. EasyPIC
™
v7 is equipped with
touchpanel controller and connector for
4-wire resistive
touchpanels
. 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. Touchpanel is ment to be mounted onto
the GLCD 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 SW3 to enable
Touch panel controller
Touchpanel is enabled using
SW3.5
,
SW3.6
,
SW3.7
and
SW3.8
switches.
They connect
READ-X
and
READ-Y
lines
of the touchpanel with
RA0
and
RA1
analog inputs, and
DRIVEA
and
DRIVEB
with
RC0
and
RC1
digital outputs
on microcontroller sockets. Do not
connect additional boards or otherwise
interfere with these lines while you use
touchpanel, because you may corrupt the
results of the readings and get inacurate
touch coordinates.
page 26
GLCD 128X64
TOUCHPANEL
CONTROLLER
Q14
BC856
Q12
BC846
VCC-MCU
Q15
BC856
Q13
BC846
R16
1K
R14
R12
1K
C25
100nF
C26
100nF
R22
10K
LEFT
TOP
RIGHT
LEFT
TOP
RIGHT
BOTTOM
10K
R24
10K
R45
10K
R15
10K
R25
100K
R23
1K
VCC-MCU
R26
100K
Q16
BC846
VCC-MCU
BOTTOM
DRIVEB
CN29
DRIVEA
VCC-MCU
SW3
RA0
RA1
RC0
RC1
ON
DATA BUS
BOTTOM
LEFT
DRIVEA
DRIVEB
LEFT
Figure 13-4: Touch Panel controller
and connection schematics
displa
ys
