风向单片机测量系统的设计—硬件部分.doc

风向单片机测量系统的设计—硬件部分

摘 要

风场风向的研究在风场建设中十分重要，本设计提供了一种以高精度环形电位计为传感器的风向测量系统。此系统主控电路由单片机AT89C51，“看门狗”电路MAX813L，电压转换模块组成。主控电路中AT89C51为系统中央处理器；电压转换模块为系统提供各芯片所需工作电压；“看门狗”电路有防止单片机死机的作用。风向标的偏向角与高精度电位计的输出电压成正比，输出电压经A/D转换芯片ADC0832输入通道进入芯片内部转换成数字信号，数字信号由A/D转换芯片ADC0832输出端输入到单片机AT89C51后由编程实现对其的运算处理。单片机处理结果可以通过RS-485串行接口传输到其他外部设备。
关键词：风向测量系统；高精度环形电位计；AT89C51；ADC0832

Abstract

The study of the wind direction for wind fields is very important. This design provides a high-precision circular potentiometer to the sensor test system of the wind direction. The control circuit of this system consists of the single chip AT89C51, "watchdog" circuit MAX813L, voltage conversion module. In this system, the single chip AT89C51 is CPU (Central Processing Unit); the "watchdog" circuit can prevents the microcontroller crash; voltage conversion module can provide working voltage for various system chip. The vane bias angle is proportional to the high-precision potentiometer output voltage. After output voltage converted though A/D to the ADC0832 chip, it import channel into the internal chip to convert into digital signals. Digital signal will input single chip AT89C51 from the A/D conversion chip to ADC0832 output terminal chip, then the programming can operation to this system. The results of single chip processing can be transmitted through the RS-485 serial interface to the other peripherals.
Keywords: wind test system; the high precision circular potentiometer; AT89C51; ADC0832

目 录

引 言 1
第一章 风向测量系统概述 2
1.1 风向采集系统介绍 2
1.2 主控模块 2
1.2.1 89C51的主要特性及管脚说明 2
1.2.2 看门狗电路 5
1.2.3 电压转换电路 6
1.2.4 外部时钟电路 7
第二章 风向传感器 8
2.1 风向传感器原理 8
2.2 信号调理电路 9
2.2.1 ADC0832芯片介绍 9
2.2.2 芯片ADC0832A/D转换的工作时序 11
第三章 串行接口设计 12
3.1 RS-485标准接口 12
3.2 芯片MAX485介绍及使用方式 12
3.2.1 串口方式选择 14
3.2.2 AT89C51通信波特率设置 15
结 论 17
参考文献 18
附 录 19
谢 辞 20