Programming a TouchScreen

[a doc]

Hi,

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin. Does
anyone know how i will be able to set a resolution, then re-route the
signal as a serial mouse command?

If anyone has any expereince in this please let me know, alex

alexdocherty at sympatico.ca

 

[Alan Balmer]

Hi,

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin.

Don't your textbooks and your class work give you any idea where to
start? In any case, you've posted to the wrong newsgroup. This
newsgroup deals with questions about the standard C language.

I don't know the proper newsgroup offhand, but since you're posting
from Google Groups, you have no excuse for not being able to find one.

 

[Malcolm]

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin.

You need to begin with what you have.
For instance do you have hardware, or do you have to build it yourself?
I also have no idea what an AMTEL AVR 90s8535 is? Is it some sort of
microprocessor?

Presumably you have a C compiler and processor somewhere in your system. At
a low level, processors usually talk to peripherals via memory-mapped ports.

So the place to start is to get some IO device hooked up to your processor,
and a C program performing IO - eg inputting a number, incrementing it, and
outputting it.
Once you know the C system is working, the next thing to do is to get the
touch screen working - so you accept input and produce some sort of output.
The final stage is to get the C program to produce the output you want for
specified input via high-level logic.

 

[Emmanuel Delahaye]

a doc wrote on 21/09/05 :

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin. Does
anyone know how i will be able to set a resolution, then re-route the
signal as a serial mouse command?

If anyone has any expereince in this please let me know, alex

How is this a C question ?

You have a design problem. Get information about the hardware, the
interfaces, the flowchart, the timings.

Then write the algorithms, and finally, translate the algorithms into
code (C or whatever).

could be helpful for design details.

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

"Mal nommer les choses c'est ajouter du malheur au
monde." -- Albert Camus.

 

[Roberto Waltman]

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin. ....

Try the following groups:
comp.arch.embedded -
comp.robotics.misc -(even if your project has nothing to do with
robotics, this group can provide a wealth of embedded SW and
electronics/interface related info.)

And the following web sites:
http://www.avrfreaks.net/
http://r.webring.com/hub?ring=avr
http://www.ipass.net/hammill/newavr.htm

Come back to this group when you have a C language question.

Roberto Waltman

[ Please reply to the group, ]
[ return address is invalid. ]

 

[adoc]

well, thanks to for the information, those of you who helped. The program
must be written in C and read by a microcontroller.

alex

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin. ....

Try the following groups:
comp.arch.embedded -
comp.robotics.misc -(even if your project has nothing to do with
robotics, this group can provide a wealth of embedded SW and
electronics/interface related info.)

And the following web sites:
http://www.avrfreaks.net/
http://r.webring.com/hub?ring=avr
http://www.ipass.net/hammill/newavr.htm

Come back to this group when you have a C language question.

Roberto Waltman

[ Please reply to the group, ]
[ return address is invalid. ]

 

[Daniel Rudy]

At about the time of 9/21/2005 11:26 AM, Malcolm stated the following:

You need to begin with what you have.
For instance do you have hardware, or do you have to build it yourself?
I also have no idea what an AMTEL AVR 90s8535 is? Is it some sort of
microprocessor?

I do. It's a 8-bit RISC microcontroller (embedded control processor)
that is manufactured by Atmel. Info here:
http://www.atmel.com/products/AVR/

I personally have used the ATMega series controllers for my embedded stuff.

 

[Mabden]

Hi,

For a 3rd year electronic engineering project i will need to program a
touch screen. I will have to interface the screen, a 5 wire resistive
model to an ATMEL AVR 90s8535. I have no idea where to begin. Does
anyone know how i will be able to set a resolution, then re-route the
signal as a serial mouse command?

If anyone has any expereince in this please let me know, alex

I do this everyday. It is called a Palm. You tap the little stylus on
the screen and the OS sends an event to your program. The latest Treo is
also a phone, a jukebox, and a camera. The programming environment is
pure C, but no one here likes to talk about it... :-(

Whatever you are trying to do with wires is like learning how to create
a Difference Engine (Google "Babbitt") to add a column of numbers. Not
worth the effort. But good luck with that degree.

An EE is like saying you were in the Marines. It's not what you learned
doing it, it is just really impressive that you got through it alive and
sane. Of course, no one has...

 

[Eric Sosman]

Mabden wrote On 09/22/05 09:40,:

[...]
Whatever you are trying to do with wires is like learning how to create
a Difference Engine (Google "Babbitt") [...]

Google gives me the title character in Sinclair Lewis'
novel, the twentieth-century American twelve-tone composer,
various firms that manufacture Babbitt bearings, and assorted
other references -- none of which have any obvious connection
to the Difference Engine of Charles Babbage.

Has there been a slippitt in your verbiitt? Have you
suffered a mental blockitt? What produced this cleavitt
between languitt and usitt? Are you simply unappreciative
of our herititt, like so many other New Itt underitt
teenittrs? I hope the damitt is by now assuittd.

 

[Michael Coyne]

Google gives me the title character in Sinclair Lewis'
novel, the twentieth-century American twelve-tone composer, various firms
that manufacture Babbitt bearings, and assorted other references

Thank goodness I was ve-wy ve-wy quiet while you were hunting babbitts.

 

[Alan Balmer]

well, thanks to for the information, those of you who helped. The program
must be written in C and read by a microcontroller.

I hope you realize that the best help you got was the advice to post
in a group where the subject is topical. Perhaps not - I haven't
noticed the query in comp.arch.embedded, which would be one of the
more obvious choices.

The fact that the program "must be written in C" does not make it
topical here, unless you encounter C language problems or questions
while you are writing it. If you do, please post here.

You cannot expect C programmers, in general, to know much about ATMEL
AVR 90s8535 chips. Also, keep in mind that any information you get
about them here is NOT going to be reviewed and verified by
knowledgeable peers, and could be utter hogwash.

BTW, the advice you got about using the resources you have and
investigating the subject yourself was good, as well. When you
graduate, and work in the real world, you can't count on having
someone else hand you the solution.

Do the best you can, and go for help when you get stuck.