基于 51 单片机的水质检测系统设计[摘要] 本系统是基于低功耗的 AT89S51 单片机，通过 NE555 定时器构成的多谐振荡器产生一定频率的波，再通过单片机的 I/O 接口对捕获高低电平的读出频率，然后通过程序算法处理抽换算成电阻的值，使用 DS18B20 作为温度采集模块，用 RS485 实现远距离传送。经过主机的数据转换和处理，将温度值通过字符液晶 1602 显示器显示。本设计结构简单，使用灵活，具有很大的使用和讨论价值。[关键字] AT89S51 单片机 NE555 定时器 DS18B20 RS485 通信 [Abstract] The system is based on low power consumption AT89S51 MCU, through the Ne555 timer control generates a certain frequency of the wave, and then through the MCU’s I / O interface to capture level read frequency, and then through the program algorithm is converted into the pumping resistance value, use DS18B20 as the temperature acquisition module, using RS485realize long-distance transmission. After a host data processing and conversion, the temperature value through the character LCD 1602LCD to display. This design has the advantages of simple structure, flexible use. It has great application and research value.[ Key words ] AT89S51MCU Ne555 timer control DS18B20 RS485 communication protocol 目 录第 1 章 引言...............................................................2第 2 章 水质检测的因素.....................................................32.1 一般水质检测的因素.................................................32.2 电子设备检测的因素.................................................32.3 水质与水的导电率的相互关系.........................................3第 3 章 系统设计要求及总体设计方案.........................................43.1 系统设计要求.......................................................43.2 总体设计的总体设计方案.............................................4第 4 章 系统各组成单元方案设计与论证.......................................54.1 测量电阻模块方案设计......
