Analog Devices Blackfin Landscape LCD EZ-Extender ADZS-BFLLCD-EZEXT, Руководство пользователя

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LCD Touch Controller (AD7879)
1-4 Blackfin Landscape LCD EZ-Extender Manual
LCD Touch Controller (AD7879)
The Blackfin Landscape LCD EZ-Extender is shipped with a low-cost
resistive touch controller (Analog Devices AD7879). The four pins gener-
ated by activating the LCD display (X+, X-, Y+, Y-) connect to a single
connector (
P1
), controlled via the LCD display. You can access the con-
troller via the SPI interface of the Blackfin processor. The controller
generates an interrupt request for the processor whenever any new data is
available or when a user touches the LCD Display. The processor uses the
SPI interface to read the appropriate registers of the AD7879 controller.
The IRQ line connects the AD7879 controller to the processor via the
processor’s general-purpose I/O (GPIO) pin. By default, the AD7879
controller uses the SPI select 1 and
GPIO1
pins. “Jumper Settings” on
page 2-3 describe how the GPIO and SPI selects can be varied for differ-
ent EZ-KIT Lites and EZ-Boards.
For more information about the AD7879 touch controller, go to
www.analog.com
and search for
AD7879
.
An example program demonstrating capabilities of the touch controller is
available in the
Examples
folder of the installation directory.
Capacitive Touch Controller (AD7147)
The Landscape LCD EZ-Extender is equipped with a CapTouch™ pro-
grammable controller (Analog Devices AD7147) for applications
implementing push buttons and scroll wheels. The four push button sen-
sors and one scroll wheel are located on the top side of the extender’s
printed circuit board (PCB).
When the respective sensor is activated, the captouch controller recognizes
and communicates the change to the Blackfin processor via the processor’s
2-wire interface (TWI). The AD7147 controller generates an interrupt
request for the Blackfin processor whenever any new data is available or