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For touch screen application system, there
are two major system designs currently in
the market, the embedded system design and
the X86-based system design. They are
completely different in the way the touch
controller bundled into the system.
For embedded system such as PDA, GPS,
digital frame,... etc., the designers may
need to develop its own driver or software.
For this kind of application, using IC chips
with touch controller function such as TI,
Philips, Wolfson, could be the most
convenient way.
For a X86- or RISC-based platform, designers
need a complete kit of touch hardware,
firmware and drivers. It is not necessary to
develop hardware/software for touch function
individually or separately; PenMount
provides the total solution to this kind of
designs and platforms.
There is another alternative to have touch
function in the system and that is via
Embedded Controller (EC). In this case, all
hardware, firmware, system software and
utilities need to be developed by the
designer themselves. In this type of
applications, the designer needs to have
full experience with touch screen
application and the capabilities of
developing the system. With this approach,
designers can have the optimum performance
of the touch screen; one such example is the
Dialogue’s FlyBook notebook PC series.
If you are considering to control the touch
screen via designing EC into your system,
you have to complete the system design
independently in the limited space of ROM,
develop firmware of touch controller and
make it compatible with system BIOS, and
configure the related peripheral input and
output devices. In general, developing such
a touch controller by EC can decrease MCU
cost. The key design job is to handle the
analog signal transmission of touch screen
to digital signal, via external circuit
design or internal Analog to Digital
Converter (ADC) component to connect to the
system through internal bus such as LPC,
SMBus, SPI, or I²C interfaces. In this way,
USB or RS-232 output port will not be
occupied. Users can then have more external
ports to use, and the power consumption will
be reduced.
In this EC type design, the use of the end
product is usually clearly defined. System
designers plan hardware, firmware and
software design schemes, and develop
application kits accordingly by themselves.
This method seems easy, it’s a challenge to
develop the touch driver however. The reason
is, first, there are various technologies of
different touch screens which are not
standardized in the various operating
systems, and the hardware and firmware need
to be developed individually. Unlike other
standard input devices such as mouse or
keyboard for which users can use without
having a special driver installed. The same
situation happens on Windows Vista OS. Under
Windows Vista OS, there is a protocol
supporting touch screen operating. Because
the related touch control hardware and
firmware are not standardized, special
efforts is still needed.
The majority in the touch screens world is
with the resistive type as of today. There
are some specific IC components integrating
audio function, ADC, resistive touch screen
controller functions, and offer SPI or I²C
interface. However the offering for a
complete driver is rare, and system
designers inevitably need to design, compile
and complete the needed drivers, and do all
software maintenance after. If you plan to
apply touch screen into notebook PC with EC
type approach, we recommend you to analyze
the whole situation carefully with
cost-effectiveness viewpoint. Using
professional PenMount touch controller
solutions and with PenMount team’s helps,
you should get to the market much quicker
with more stable system and at reasonable
cost.
We have 16 years in the experience of
developing PenMount touch controller. The
provided solution, including the software
and hardware has been greatly proven to meet
and fulfill customer’s needs. Whether touch
screen or touch controller solution,
PenMount is your best choice and partner.
For more PenMount controllers and
drivers information, please visit our
websites:
http://www.salt.com.tw and
http://www.penmount.com.
Please feel free to contact us at our email
address salt@salt.com.tw
or service@penmount.com . |
