The system of 24-channel digital potentiometers based on single-chip microcomputer

This paper introduces that using digital potentiometers output 24-channel resistance to simulate the thermistors. Every channel has two digital potentiometers, one is low resolution and high value, the other is high resolution and low value. They are connected through Daisy-Chain and share chip-select. 24-channel digital potentiometers share the SPI´s clock and SDI. Input the parameter in the computer and then send it to the single-chip microcomputer. The single-chip microcomputer receives the parameter and sends it to the digital potentiometers. After correcting the errors, the system meets the demands which are resistance range of 0~40KΩ and maximum error of 15Ω. The design can replace the traditional way in which the mechanical potentiometers are used to simulate the thermistors.