农业机械自动调高装置微电容检测系统的设计

Design of Automatic Height- adjustment Device Micro- capacitance Detection System in Agricultural Machinery

农业机械的自动化程度越来越高,自动检测与控制技术在农业机械中的作用越来越大,从而等距控制的自动调高装置需求量与日俱增。本文根据自动调高装置的要求,设计了基于单片机STC89C52R和电容数字转换芯片AD7746的微电容检测系统,详细阐述了系统的硬件组成及其接口电路,分析了系统的软件组成及编程原理。通过AD7746电容数字转换芯片实现了对电容传感器的信号采集与数字转换,利用单片机分别实现对AD7 7 4 6控制及上位机的通信。最后,通过实验获取了检测系统的本底电容和测量精度。

Degree of agricultural machinery automation is increasing,the role automatic detection and control technology is increasing,automatic height- adjustment device automatically increase the demand is growing. According to the requirement of automatic height- adjustment device,micro- capacitance detection system based on AD7746 and microcontroller STC89C52 was designed. The hardware,software,interface circuit and program data flow were explained in detail. AD7746 was used to finish signal's collection and digital conversation. STC89C52 microcontroller was used to finfish controlling AD7746 and communicating with computer. Experiment was conducted to obtain the detecting system's background capacitance and measurement accuracy.