Touch screen 4-wire interface

[Demon]

Hi,


Has anyone had any success in connecting a touch screem using 4-wire technology to a PIC?

If you have, code snippets as well as a schematic would go a long ways. Here is what I've found so far, the 4-wire circuitry is the larger box across the center. It has 4 wires from the touch screen, and 6 wires to the PIC.

I'm told this circuit is pretty much 'good', for what that's worth. What I lack is the code to interpret the information at the PIC end. BASIC would be nice, but I'd take Assembler code at this point. :D

Thanks, and have a nice day!


Robert
:)

[Luciano]

See this link:
http://www.circuitcellar.com/library/print/0100/dahlin-114/dahlin114.pdf

Luciano

[Demon]

Thanks Luciano!

Great article. It also uses a ADS7843D chip to receive the data from the 4-wire, making my life even easier.

The code for the schematic (figure 3) is excellent. Very well commented, even I can understand what is going on, and best of all, it's in PIC BASIC Pro!

ftp://ftp.circuitcellar.com/pub/Circuit_Cellar/2000/114/Dalhlin.ZIP

I've emailed Mr. Dahlin already and asked if I can have permission to use his code in my application. I hope that email addy in the article is still good.

Robert
:cool:

[egayam]

Does anyone have a code in C?

What PIC should the right one to interface to touchscreen?

Thank you.

[njoyalappatt]

Am trying to interface a 4wire resistive touch screen to pic 16F877A. I have connected it to 4,5,6,7 pins (adc pins).I want to control my two motors of the moving robot; ie, when i touch on 4 different positions, it has to move left, right, front,and backward. I like to know how to write the interfacing program.. (if possible in mikroc)

[Demon]

You would have better luck getting help with Mikro C from their forums:
http://www.mikroe.com/forum/

Robert

[Acetronics2]

Hi, njoyalapatt

you'd better download the last MikroCPro for Pic compiler : in the provided examples, you will find how to use your GLCD touchscreen ...
you'll also have libraries to easily drive the GLCD and touchscreen.

May I talk about Visual GLCD ( another product from Mikroelektronika ) that helps you to easily design nice GLCD screens ...

Moreover, If you are an owner of a MikroC license ... just ask for and the MikroCPro licence key will be returned to you for free.

The old MikroC is not " the thing " for such a project, and overall PBP,as you have to Write your own libraries for GLCD and for Touchscreen.



Alain