microcontroller for capacitive touch screen?

We are thinking to interface LCD and this touch screen through a
microcontroller.
Is there any company available that provides microcontroller for
capacitive touch screens?

"Ajab" <jasusvijay@yahoo.com> wrote in message 
news:1186130849.737047.102980@q3g2000prf.googlegroups.com...
> We are thinking to interface LCD and this touch screen through a
> microcontroller.
> Is there any company available that provides microcontroller for
> capacitive touch screens?

For capacitive screens then the controller needs to be very closely 
married to the touchscreen and you would do well to use a controller and 
screen from the same manufacturer. Also, I'm not aware of any MCU's that 
have a capacitive controller and I bleieve it is for that reason.

Are you sure you don't want a resistive screen - they are cheaper, 
simpler and many MCU's have built in controllers which are compatible 
with nearly all screens. For vandal-sensitive uses then they can be 
almost as tough as capacitive screens.

I've worked with both types and have settled on resistive screens after 
much heartache and many reliability problems with capacitive. It also 
means I can write my own driver for it and I'm not tied to someone 
else's controller protocol. 

In article <1186130849.737047.102980@q3g2000prf.googlegroups.com>, Ajab 
<jasusvijay@yahoo.com> writes
>We are thinking to interface LCD and this touch screen through a
>microcontroller.
>Is there any company available that provides microcontroller for
>capacitive touch screens?


Sharp ARM parts... now NXP ARM part since they bought them.

ARM7 core with screen controller built in
-- 
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills  Staffs  England     /\/\/\/\/
/\/\/ chris@phaedsys.org      www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

"Chris Hills" <chris@phaedsys.org> wrote in message 
news:HF8LtCBbHysGFAzD@phaedsys.demon.co.uk...
> In article <1186130849.737047.102980@q3g2000prf.googlegroups.com>, Ajab 
> <jasusvijay@yahoo.com> writes
>>We are thinking to interface LCD and this touch screen through a
>>microcontroller.
>>Is there any company available that provides microcontroller for
>>capacitive touch screens?
>
>
> Sharp ARM parts... now NXP ARM part since they bought them.
>
> ARM7 core with screen controller built in

Which ones might they be? The (ex-)Sharp parts that I'm aware of have ADC 
subsystems suitable for resistive touch screens but not capacitive ones.

-- 
Peter 

"Peter Dickerson" <firstname.lastname@REMOVE.tesco.net> wrote in message 
news:QUFsi.8450$S91.2724@newsfe7-win.ntli.net...
> "Chris Hills" <chris@phaedsys.org> wrote in message 
> news:HF8LtCBbHysGFAzD@phaedsys.demon.co.uk...
>> In article <1186130849.737047.102980@q3g2000prf.googlegroups.com>, 
>> Ajab <jasusvijay@yahoo.com> writes
>>>We are thinking to interface LCD and this touch screen through a
>>>microcontroller.
>>>Is there any company available that provides microcontroller for
>>>capacitive touch screens?
>>
>>
>> Sharp ARM parts... now NXP ARM part since they bought them.
>>
>> ARM7 core with screen controller built in
>
> Which ones might they be? The (ex-)Sharp parts that I'm aware of have 
> ADC subsystems suitable for resistive touch screens but not capacitive 
> ones.

That's correct, they are very good for resistive screens (up to 8 wire 
is supported) but to use a capacitive screen you need to use a UART to 
talk to a controller. If you were very clever with a bit of analogue 
circuitry you might be able to put together something to control a 
capacitive screen using the existing ADC but it would be pretty hard. 

Ajab wrote:
> We are thinking to interface LCD and this touch screen through a
> microcontroller.
> Is there any company available that provides microcontroller for
> capacitive touch screens?
> 
I haven't tried it, but here's one:

http://www.onfulfillment.com/cypressstore/Product.aspx?srch=CY3214-PSoCEvalUSB&p=742&sid=205

Currently, we use resistive 4 wire for GUI input and I've wondered if 
capacitive would work better (not so pressure sensitive). I haven't 
figured out what the capacitive sensor configuration would be for a 
graphical input (X/Y). Anybody know?
Bob

Ajab wrote:
> We are thinking to interface LCD and this touch screen through a
> microcontroller.
> Is there any company available that provides microcontroller for
> capacitive touch screens?
> 
Cypress is pushing the 8bit PSOC for this.  The have an eval kit.
I think TI has the same thing with the 430

Ajab wrote:
> We are thinking to interface LCD and this touch screen through a
> microcontroller.
> Is there any company available that provides microcontroller for
> capacitive touch screens?

Qprox chips provide a self-calibrating ready made solution with 
serial outputs. Parts are available to scan up to 8x8 matrix:

   http://www.qprox.com/products/qmatrix_whitepaper.php

It looks as though you might need two layers of transparent 
conductor on your LCD.

Jan Coombs
-- 

On Aug 4, 12:21 pm, jan <jans...@murray-microft.invalid> wrote:
> Ajab wrote:
> > We are thinking to interface LCD and this touch screen through a
> > microcontroller.
> > Is there any company available that provides microcontroller for
> > capacitive touch screens?
>
> Qprox chips provide a self-calibrating ready made solution with
> serial outputs. Parts are available to scan up to 8x8 matrix:
>
>    http://www.qprox.com/products/qmatrix_whitepaper.php
>
> It looks as though you might need two layers of transparent
> conductor on your LCD.
>
> Jan Coombs
> --

I want to use capacitive screens because the resistive ones get easily
damaged by sharp objects.(this is what i read).

Cypress has  micros with dedicated capacitive touch screen interface.
http://www.cypress.com/capsense/index.jsp

"Ajab" <jasusvijay@yahoo.com> wrote in message 
news:1186378925.113550.149540@j4g2000prf.googlegroups.com...
> On Aug 4, 12:21 pm, jan <jans...@murray-microft.invalid> wrote:
>> Ajab wrote:
>> > We are thinking to interface LCD and this touch screen through a
>> > microcontroller.
>> > Is there any company available that provides microcontroller for
>> > capacitive touch screens?
>>
>> Qprox chips provide a self-calibrating ready made solution with
>> serial outputs. Parts are available to scan up to 8x8 matrix:
>>
>>    http://www.qprox.com/products/qmatrix_whitepaper.php
>>
>> It looks as though you might need two layers of transparent
>> conductor on your LCD.
>>
>> Jan Coombs
>> --
>
> I want to use capacitive screens because the resistive ones get easily
> damaged by sharp objects.(this is what i read).
>