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大庆石油学院应用技术学院毕业论文I摘要电热水锅炉是采用最新电热技术及控制系统设计完成的经济、节能、安全、效率高、故障低、易维护的先进水平锅炉。电热水锅炉特点:1、全自动智能化控制技术,无人值守；2、工作方式灵活，可设置为手动或自动模式；3、可在负荷变化时确保给水泵、循环泵自动启停，也可手动控制；4、环保运行，无噪音，无污染，热效率高，散热损耗小，热效率大于98%；5、锅炉占地面积小，节省场地。当今环境保护问题已深入人心，首先就是温室效应带来的全球变暖，科学家预测：如果地球表面温度的升高按现在的速度继续发展，到2050年全球温度将上升2－4摄氏度，南北极地冰山将大幅度融化，导致海平面大大上升，一些岛屿国家和沿海城市将淹于水中，其中就包括祖国的明珠上海。与普通锅炉相比我们做的电热水锅炉不需要释放大量的浓烟，不需要排放炉渣，而且没有噪声，所以电热水锅炉很环保；热效率方面，普通煤加热锅炉的热效率能达到75%-85%，而电热水锅炉在热效率方面更强能够达到95%左右；温度采用多点DS18b20进行测量；当前液位利用超声波技术进行测量；数据传输本系统采用无线数据传输技术；上位机采用三维力控组态软件做的监控界面，用于监控电热水锅炉的当前状态；本系统的控制芯片为Atmel公司生产的高性能、低功耗、8位AVR微处理器ATmega8。关键词电加热；锅炉；超声波；无线通信；组态监控；DS18b20；AVR大庆石油学院应用技术学院毕业论文II目录第1章系统简介·······································································3第2章系统硬件·······································································32.1ATmega8简介······································································32.2超声波简介········································································52.2.1引言···········································································52.2.2超声波测距原理······························································52.2.3超声波测距系统的电路设计················································62.3DS18B20简介······································································82.4无线模块SRWF-501简介·······················································112.4.1引言··········································································112.4.2无线模块的特点·····························································112.4.3无线模块的应用领域························································122.4.4无线模块的使用方法························································122.4.5无线模块的注意事项························································13第3章系统软件·····································································133.1三维力控组态软件介绍·························································133.1.1概述··········································································133.1.2主要技术指标································································133.1.3软件功能简介································································143.2Modbus通信协议································································163.2.1MODBUS总线简介···························································163.2.2MODBUS协议简介···························································173.2.3MODBUS通讯信息传输过程················································173.2.4MODBUS功能码简介························································183.2.5错误校校验验码（CRC）··················································193.2.6通讯错误信息及数据的处理··············································20第4章电路图与程序清单·························································224.1电路图···········································································224.2程序清单·········································································234.2.1总程序.c····································································234.2.2touwenjian.h··································································304.2.3wendu.h·······································································304.2.4tongxin.h·····································································314.2.5chushihua.h···································································334.2.6quanjubianliang.h·····························································34参考文献·················································································35致谢························································································36大庆石油学院应用技术学院毕业论文3第1章系统简介随着社会的发展和人民生活水平的不断提高，电子产品越来越普及，尤其是节能、环保、效率高、智能的电子产品越来越受到人们的喜爱。电热水锅炉是采用最新电热技术及控制系统设计完成的经济、节能、安全、效率高、故障低、易维护的先进水平锅炉。电热水锅炉特点:1、全自动智能化控制技术,无人值守；2、工作方式灵活，可设置为手动或自动模式；3、可在负荷变化时确保给水泵、循环泵自动启停，也可手动控制；4、环保运行，无噪音，无污染，热效率高，散热损耗小，热效率大于98%；5、锅炉占地面积小，节省场地。当今环境保护问题已深入人心，首先就是温室效应带来的全球变暖，科学家预测：如果地球表面温度的升高按现在的速度继续发展，到2050年全球温度将上升2－4摄氏度，南北极地冰山将大幅度融化，导致海平面大大上升，一些岛屿国家和沿海城市将淹于水中，其中就包括祖国的明珠上海。与普通锅炉相比我们做的电热水锅炉不需要释放大量的浓烟，不需要排放炉渣，而且没有噪声，所以电热水锅炉很环保；热效率方面，普通煤加热锅炉的热效率能达到75%-85%，而电热水锅炉在热效率方面更强能够达到95%左右；温度采用多点DS18b20进行测量；当前液位利用超声波技术进行测量；数据传输本系统采用无线数据传输技术；上位机采用三维力控组态软件做的监控界面，用于监控电热水锅炉的当前状态；本系统的控制芯片为Atmel公司生产的高性能、低功耗、8位AVR微处理器ATmega8。第2章系统硬件2.1ATmega8简介ATmega8是ATMEL公司在2002年第一季度推出的一款新型AVR高档单片机。在AVR家族中，ATmega8是一种非常特殊的单片机，它的芯片内部集成了较大容量的存储器和丰富强大的硬件接口电路，具备AVR高档单片机MEGE系列的全部性能和特点。但由于采用了小引脚封装（为DIP28和TQFP/MLF32），所以其价格仅与低档单片机相当，再加上AVR单片机的系统内可编程特性，使得无需购买昂贵的仿真器和编程器也可进行单片机嵌入式系统的设计和开发，同时也为单片机的初学者提供了非常方便和简捷的学习开发环境。ATmega8的这些特点，使其成为一款具有极高性能价格比的单片机，深受广大单片机用户的喜爱，在产品应用市场上极具竞争力，被很多家用电器厂商和仪器仪表行业看中，从而使ATmega8迅速进入大批量的应用领域。ATmega系列单片机属于AVR中的高档产品，它承袭了AT90所具有的特点，并在AT90（如AT9058515、AT9058535）的基础上，增加了更多的接口功能，而且在省电性能，稳定性、抗干扰性以及灵活性方面考虑得更加周全和完善。ATmega8是一款采用低功耗大庆石油学院应用技术学院毕业论文4CMOS工艺生产的基于AVRRISC结构的8位单片机。AVR单片机的核心是将32个工作寄存器和丰富的指令集联结在一起，所有的工作寄存器都与ALU（算术逻辑单元）直接相连，实现了在一个时钟周期内执行的一条指令同时访问（读写）两个独立寄存器的操作。这种结构提高了代码效率，使得大部分指令的执行时间仅为一个时钟周期。因此，ATmega8可以达到接近1MIPS/MHz的性能，运行速度比普通CISC单片机高出10倍。ATmega8的主要性能如下：*高性能、低功耗的8位AVR微控制器，先进的RISC精简指令集结构130条功能强大的指令，大多数为单时钟周期指令32个8位通用工作寄存器工作在16MHz时，具有16MIPS的性能片内集成硬件乘法器（执行速度为2个时钟周期）*片内集成了较