I want to make a system i'm designing touch screen. First can any one help me on were to buy them from. Secondly, i see there are some that come with out the controller, and some that come with the controller. Does the controller make it touch screen, or does the screen make it touch screen? I know that there are different types of touch screens, but will any LCD controller work with any screen?

 

The controller acts as the driver; the touchscreen will provide the basic touchscreen functionality. As for any LCD controller, do you have one in mind? Typically a generic microcontroller can be used to drive the touchscreen. I have used a combo fo uCs and FPGAs to provide hardware drive touchscreen UIs for microcomputing applications in the past. A lot depends on components obviously.

Dave

 

From my experience, a touch screen is not built into an LCD. The touch screen is a plate connected to a controller board, and lays on top of the LCD. Many POSs use this setup.

 

You can buy touch screen panel (without the LCD) from RS. http://www.rssingapore.com and search "touch screen". The touch screen is basically a resistive pad (passive with no electronics). The controller is basically a ADC (read AD7877 datasheet and you will roughly get some ideas).