This article demonstrates a hardware and software solution for controlling the DS1803 using a Dallas Semiconductor 8051-compatible microprocessor, the DS87C520. It describes how to generate the 2-wire signaling required for communication via two port pins on the microcontroller. A basic schematic shows the necessary connections between the microprocessor and the DS1803, and 8051 assembler code provides a small application for controlling the chip’s two digital potentiometers using different write modes. After each write cycle, the application reads back the information from the DS1803 and displays it on a PC via a serial port to demonstrate a properly operational read function. Source code for the application described in this article is included. Read full article.