基于STM32的多路温度采集系统设计

Design of Multichannel Temperature Acquisition System Based on STM32

设计了一种基于STM32的多路温度采集系统,阐述了系统的实现方法及设计方案。系统以STM32 F103 C8 T6作为核心控制器,以四线制PT100铂电阻作为温度传感器,由控制器控制多路模拟开关地址信号实现多路温度传感器选取。为提高系统测温准确性和稳定性,采用三电阻自校正法提高PT100电阻值计算精度,数字隔离电路隔离控制系统与现场信号,增强系统抗干扰能力,并对恒流源电路和信号调理电路进行了分析设计。在系统软件上,采用PT100分度函数分段线性拟合,以简化电阻—温度换算过程,提升软件执行效率。实验测试表明,在0~1 0 0℃测温范围内,系统测温精度为±0.1℃,测温分辨率为0.0 1℃,能够满足2 2路温度数据采集的需要。

A multichannel temperature acquisition system based on STM32 was introduced,and the implementation method and design scheme of the system were elaborated. The STM32 F103 C8 T6 was used as the core controller and the fourwire PT100 platinum resistance was used as the temperature sensor in the system. The multiplex analog switch address signal was controlled by the controller to realize the selection of multiple temperature sensors. In order to improve the accuracy and stability of the temperature measurement system,the three-resistor self-calibration method was used to improve the accuracy of the PT100 resistance value,and the digital isolation circuit was used to isolate the control system from the on-site signals to enhance the system＇s anti-interference ability,and the constant current source circuit and the signal conditioning circuit were analyzed and designed in detail. In the system software,a piece-wise linear fitting of the PT100 index function was used to simplify the resistance-temperature conversion process and improve the software execution efficiency. The experimental test showed that within the range of 0 ℃ ~ 100 ℃ temperature measurement,the system temperature measurement accuracy was± 0. 1 ℃,and the temperature resolution of was 0. 01 ℃,which can meet the demands of 22-channel temperature data acquisition.