User`s guide
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. EasyMx PRO
™
v7 is equipped
with touchpanel controller and connector for 4-wire
resistive touchpanels. It can very accurately register
pressure at a specic point, representing the touch
coordinates in the form of analog voltages, which can
then be easily converted to X- and Y- values. Touchpanel
comes as a part of TFT 320x240 display.
page 31
Touch Panel
controller
Figure 17-2:
Turn on
switches 5
through 8 on
SW3 to enable
Touch panel
controller
Touchpanel is enabled using SW14.5,
SW14.6, SW14.7 and SW14.8 switches.
They connect READ-X and READ-Y lines of
the touchpanel with PB4 and PB5 analog
inputs, and DRIVEA and DRIVEB with PE0
and PE1 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.
DATA BUS
2
15
12
35
11
36
3
4
5
6
14
7
8
9
13
43
33
10
37
38
39
40
44
45
46
34
1
47
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
41
42
LED-K
LED-A1
LED-A2
LED-A3
LED-A4
IM0
IM1
IM2
IM3
RESET
V
SYNC
HSYNC
DOTCLK
EN ABLE
DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7
DB8
DB9
DB10
DB11
DB12
DB13
DB 14
DB15
DB16
DB17
SDO
SDI
RD
WR/SCL
RS
CS
FMARK
VCC-IO
VCC
VCC-I
G
N
D
XR
YD
XL
YU
TFT1
VCC-3.3V
RIGHT
TOP
READ-X
READ-Y
Q3
BC856
Q4
BC846
R64
10K
R63
1K
VREF
R65
10K
R67
4K7
VCC-3.3V
Q8
BC856
VREF
R68
10K
Q9
BC846
R80
10K
C29
10nF
R79
100K
Q11
BC846
R86
10K
C30
10nF
R85
100K
R84
4K7
VCC-3.3V
RIGHT
TOP
READ-X
READ-Y
DRIVEA
DRIVEB
E13
10uF
VCC-3.3V
FP4
FERRITE
E15
10uF
VCC-1.8V VREF
O
N
SW14
DRIVEA
DRIVEB
READ-X
READ-Y
PB4
PB5
PE0
PE1
1 2 3 4 5
6
7 8
Enabling Touch panel
multimedia
EasyMx PRO
v7
Figure 17-1: Touch Panel controller
and connection schematics