Analog Devices AN-738 AD7877 Touch Screen Controller Driver Application Note

About this manual

This document provides an application note (AN-738) for connecting the Analog Devices AD7877 touch screen controller to an Intel PXA25x processor running the Windows CE operating system. It includes a sample driver written for the PXA25x CPU family that utilizes the hardware SPI controller and communicates via a single GPIO pin. The driver supports advanced features such as programmable acquisition delays, averaging, conversion sequencing, and contact resistance calculation.

What's inside

• Introduction
• Driver Overview
• Files Included
• Driver Configurations
• Connecting the PXA25x to the AD7877
• Hardware Connections
• References

Frequently asked questions

What processor family is this driver specifically written for?

The sample driver is written for the Intel PXA25x CPU family.

Does connecting the AD7877 require external pull-up or pull-down resistors?

No, neither pull-up nor pull-down resistors are required because they are included on-chip in the AD7877.

What is the default sysintr value specified for the touch driver?

The default sysintr value is 0x00000019.