摘  要：中国是一个水资源严重缺乏的国家，而农业又占了总用水量的大部分，因此研究高效的自动化控制节水灌溉技术是十分必要的。本设计主要研究了基于单片机的节水灌溉控制系统。单片机选用STC89C52,主要由土壤湿度传感器、信号处理电路、显示电路、输出控制电路、按键电路等组成。A/D转换器将土壤湿度传感器检测到的模拟量转换成数字量并传送给单片机，数据显示于LCD显示屏上，按键电路用来调节土壤湿度限定值。通过单片机程序设定浇水的阀值与传感器送入单片机的土壤湿度值相比较，当低于阀值时，单片机就输出一个信号控制电磁阀打开，开始浇水。实验结果表明了此系统的可行性，达到了节水灌溉的效果。70680

毕业论文关 键 词：土壤湿度传感器，A/D转换电路，单片机，节水灌溉

Abstract: It needs water very much in China, but water is used widely in agriculture. So studying efficient auto-control water-saving irrigation technology is very necessary. This design mainly studies water-saving irrigation control system based on MCU. Based on STC89C52 MCU, the system mainly consist of soil moisture sensor, signal transfer circuit, monitor display circuit, out port control circuit and keying circuit. The soil moisture sensor embedded under the ground can check out soil moisture in analogue signal and then be handled. The digital quantity will be showed on LCD display. Key circuit is used to adjust soil humidity limit value.Through the SCM program set watering threshold value and sensors into MCU soil moisture values are compared, when below threshold value, chip output a signal controls the solenoid valve opens, started watering. The experimental results show that the feasibility of this system and achieved the effect of water saving irrigation. 

Keywords:  soil moisture sensor, A/D transform,STC89C52MCU, water-saving irrigation

目   录

1  绪论 3

1.1  研究背景 3

1.2  课题研究的目的和意义 3

1.3  课题研究内容 3

2  系统总体设计方案 4

2.1  系统的总框图 4

2.2  器件的选择 4

3  系统硬件设计 8

3.1  总电路 8

3.2  单片机的最小系统 9

3.3  数据采集电路 11

3.4  LCD显示电路 12

3.5  按键电路 12

3.6  继电器电路 12

4  系统软件设计 12

4.1  系统总流程图 13

4.2  ADC0832转换模块流程图 13

4.3  按键模块流程图 14

4.4  显示模块流程图 15

5  系统仿真与测试 15

5.1  系统仿真图 15

5.2  仿真结果与调试 16

5.3  实物图 17

结  论 19

参考文献