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In the last issue of PenMount Bulletin we
talked about the differences between
PenMount Controller and user-designed touch
controller. In this bulletin we are going to
introduce the differences between PenMount
Controller and IC chip with Built-in touch
screen signal receiving function. The most
common of these IC chips are integrated with
Analog to Digital Converter (ADC), or Audio
Codec, such as TI, Philip, Analog Device,
Wolfson, etc.
Common end products using these specified IC
chips are those with (1) Embedded system
platforms, such as ARM 7, ARM 9 platform and
single chip computer; (2) System executed
WinCE OS; (3) Small size touch screen (1” to
4.3”) applications; (4) Simple function
handheld product requiring additional audio
function; the most common of which are the
PDA, PND (Portable Navigator Device), PMP
(Portable Media Player), touch mobile phone,
Smart Phone, etc. These products do not
require high display resolution, most are
QVGA (320x240) or lower, consequently, touch
screen accuracy is not a requirement, and to
offset this, the designer can enlarge the
display image via software utility.
An example of the specified IC chip is the
Wolfson’s Audio CODEC, which has built-in
touch screen signal receiving function,
supporting 4- or 5-wire touch screen; which
looks workable from its specifications.
However, the hardware design and firmware
need to adjust many parameters when applying
to touch screen features. Another example of
the ADC with built-in touch screen signal
receiving is the TI chips (the predecessor,
Burr-Brown) is the most widely used. It has
a common point with the Wolfson series, the
internal IC circuitry design. It has simple
circuitry, does not occupy USB or RS232
port, and has low power consumption.
However, the system designer needs to
develop the touch driver and the
applications.
Presently, IC chips with built-in resistive
touch screen signal receiving function can
offer some Windows CE drivers or source code
to use in embedded system platforms.
However, there are still problems with touch
screen noise filtering, defining invalid
touch and other compatibility issues. The
whole touch performance of these specified
IC chips can not be equaled to what PenMount
touch controller can provide. If you have
time constraint or do not have sufficient
experiences and capabilities to develop
suitable touch screen controller solution,
please use PenMount touch controller and let
the PenMount team with over 16 years of
experience provide you with the perfect
touch solutions, be it touch screen solution
or touch controller solution. PenMount is
your best choice and best partner.
We take this opportunity to inform you that
the PenMount Bulletin will become bi-weekly
starting this month of May; This measure is
taken on the sound advice of our readers to
give them ample time to read and digest the
news and information the PenMount Bulletin
provides them.
We hope that our product information will
help to clarify any touch screen problems
you may have. If you have any specific
requirements, please let us know, we are
willing to help you.
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 . |
