Analog resistive touch controllers

I have designed several versions of the analog resistive touch controllers.

Prototype touch controller card

The first version used PIC16C54 with external A/D and external multiplexer. It had 10-bit resolution.

Then I designed a chip version. It has 8-bit resolution and it was compatible with the previous one.

The third version was a small, high precision (10 or 12-bit A/D) controller card. It used an external multiplexer. It reached the highest possible resolution in the usually noisy environment of the touch screen.

The fourth version was a very cheap (chip price is less than € 2) true single chip touch controller. It had 8-bit resolution only, but required no external components. It could be integrated into the cable or the connector of the touch panel.

It is pointless to make new versions of the stand-alone controller, because the third version already offers the highest possible resolution, and the fourth one offers the smallest possible size at the lowest possible price. However the touch controller functionality can be integrated into new alphanumeric and graphic LCD controllers. On a PIC16F870 only 5% of the processor time is needed for touch screen handling. PIC16F870 is ideal choice for integrated LCD and touch controllers, because it is powerful, reprogrammable and cheap (less than € 4). 

Back to home  More products  Top of the page  Request more information