touch screens picaxe

[danny009]

hi, i was looking at touchscreens and i saw that they have 4 cabels for the X and Y values. to connect them to the computer there was a little chip i was just wondering how this chip works. i would like to intergrate a small touch screen into my project but i will on need the X or Y so left to right fuction of the touch screen. so my aim is to replace the small chip which convter the 4wires in to a language that a pc can understand in to something a picaxe can do so i can use the touchscreen as a input on my project. anybody got any data sheets or in depth info on how touch screens work or a good idea on how to do this thanks.

 

[Sceadwian]

You should try google sometime, the answers are out there and not difficult to find, you could probably have found the answer to your question in less time then it took you to write this post (easily)
But I'll repeat the basics of what's out there anyways =) The cables are X+ X- Y+ and Y-
In order to read say the X+ position you source voltage to Y+ and ground Y- (creating a voltage divider) and read the voltage at X+ You can use 4 I/O pins from any micro controller that can be fed into an ADC

 

[danny009]

yes but lets say the 2.5 volts is put through x+ to x- when i touch the screen half way on both axis and read off y+ it will be 1.25v how would i get a picaxe to determin the voltage that is coming into it's input or would i use another chip? thanks alot

 

[Nigel Goodwin]

A PICAXE would be a poor choice, because they are very slow and very limited - but amazing for the price!.

 

[danny009]

yes but i dont really know any other IC any body got an idea thanks

 

[Nigel Goodwin]

yes but i dont really know any other IC any body got an idea thanks

A normal PIC instead of the limited pre-programmed PICAXE.