Touch Panel Controller - Mikroe EasyMx PRO v7a Manual

Enabling Touch panel
Touch panel is enabled using SW11.5, SW11.6, SW11.7
and SW11.8 switches. They connect BOTTOM and LEFT
lines of the touch panel with PB0 and PB1 analog inputs,
and DRIVEA and DRIVEB with PB8 and PB9 digital outputs
on microcontroller sockets. Prior to using Touch panel in
your application, make sure to disconnect other peripherals,
LEDs and additional pull-up or pull-down resistors from the
interface lines that could interfere with signals and cause
data corruption.
E a s y M x P R O v 7 a U s e r M a n u a l
TOUCH PANEL
CONTROLLER
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. EasyMx PRO v7a 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 TFT 320x240 display.
DATA BUS
PB0
PB1
PB8
PB9
SW11
GLCD-TFT SOCKET
1 20
CN29
21 24
RIGHT
TOP
LEFT
BOTTOM
VCC-3.3V VREF VCC-1.8V
E14
BOTTOM
10uF
LEFT
R59
Q3
DRIVEA
1K
VCC-3.3V
BC856
DRIVEB
R61
R63
10K
Q4 4K7
BC846
R65
RIGHT
10K
VREF
Q6
BC856
R67
10K
TOP
LEFT
Q7
BC846
R71
R70 C35
100K 10nF
10K
VCC-3.3V
BOTTOM
R75
Q8
4K7
BC846
R78
R77 C40
100K 10nF
10K
VREF
FP4
FERRITE
E15
10uF
DRIVEA
DRIVEB