基于CAN总线的多点温度监测及报警系统设计摘要本文设计的是一套基于CAN总线的多点温度检测及报警系统，主要是对粮仓的温度监控，以确保储粮的安全。系统设计分为主控模块和监控模块。主控监控两模块的微处理器都采用AT89S52单片机。为了实现主控模块对监控模块的实时监测，在主控端和监控端处都设计有CAN通信电路，由控制器SJA1000和收发器82C250组成CAN通信接口。另外，主控端的外围电路部分包括时钟电路功能模块、EEPROM存储电路模块、串口通信电路模块、译码电路功能模块、液晶显示屏模块；监控端的外围电路部分为温度传感器。主控端的时钟芯片选用DS12887，EEPROM存储芯片选用户AT24C16，显示屏采用FM12232B液晶模块。监控端的温度传感器采用数字传感器DS18B20，系统设置温度传感器的阐值为50℃。本文给出了系统的结构和软硬件设计方案，可实现实时温度测量、越限报警等功能。该系统具有可靠性好、通信速率高、抗干扰能力强等特点。本系统还适用于在粮仓、北方暖气和热水供应中心、大面积水泥铺建等多种场合。关键词：CAN总线；DS18B20；AT89S52BasedonCANbusmultipointtemperaturemonitoringandalarmingsystemdesignABSTRACTThispaperdesignsamulti-pointtemperaturedetectionandalarmsystembasedonCANbus,thissystemismainlyusedtomonitorthetemperatureofgranary,toensurethesafetyofthestoredgrain.Thissystemisdividedintothemaincontrolmoduleandthesurveillancemodule.ThemicroprocessorofthemaincontrolmoduleandthesurveillancemodulebothuseDSPAT89S52microcontroller.Inordertoachievereal-timemonitoringandmeasuringofthesurveillancemodule,CANcommunicationscircuitsaredesignedattheportofthemaincontrolmoduleandthesurveillancemodule,whichiscomposedbythecontrollerSJA1000andthe82C250communicationsinterface.Inaddition,theexternalcircuitsectionofthemaincontrolmoduleincludestheclockcircuitmodules,EEPROMmemorycircuitmodule,serialcommunicationcircuitmodule,decodingcircuitmodules,LCDmodules;themainportionoftheexternalcircuitsectionofthesurveillancemoduleisthetemperaturesensor.TheclockchipofthemaincontrolmoduleusesDS12887,theEEPROMmemorychipcanselectAT24C16,theLCDdisplaymodulecanselectFM12232B.ThetemperaturesensorofthesurveillancemoduleusethedigitalsensorDS18B20,thelininalvalueofthetemperaturesensorissettedat50℃bythesystem.Thispaperpresentsthearchitectureofthesystemandthehardwareandsoftwaredesignproposal,enablingthefunctionofreal-timetemperaturemeasurementandtheoff-limitedalarm.Thesystemhasgoodreliability,hightransmissionrate,stronganti-interferenceandsoon.Thissystemcanalsobeappliedtothegranary,thenorthcentralheatingandhotwatersupplycenter,thecementp