Datasheet

page 31
v7
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 Fusion
™
v7 is
equipped with touch panel controller and connector for
4-wire resistive touch panels. It can very accurately
register pressure at a specic 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 TFT 320x240 display.
Touch Panel
controller
Figure 17-2:
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 TOP and LEFT lines of the touch
panel with PB14 and RB15 analog inputs,
and BOTTOM and RIGHT with PB2 and PB3
digital outputs on microcontroller sockets.
Make sure to disconnect other peripherals, LEDs
and additional pull-up or pull-down resistors
from the interface lines so they do not interfere
with signal/data integrity.
VCC-3.3V
VCC-3.3V
C43
47nF
R70
300K
C44
47nF
R77
300K
E14
10uF
VCC-3.3V
TOP
LEFT
PMRD
PMWR
GND
VCC
NC
RS
NC
D1 D2 D3 D4 D5 D6 D7
CS
D0
RST
NC
+5V
BPWM
1 20
XR
YU
XL
YD
21 24
CN32
GLCD-TFT SOCKET
RIGHT
TOP
LEFT
BOTTOM
1 2 3 4 5 6 7 8
O
N
SW11
RB3
RB14
RB15
RB2
TOP
LEFT
RIGHT
BOTTOM
DATA BUS
Enabling Touch panel
multimedia
Figure 17-1:
Touch Panel
controller and
connection schematic