文档介绍：摘要
随着社会的不断进步发展,人们对燃气热水器的要求越来越高。而现今大多数热水器还是处于手动调温阶段,热水温度不能实时显示,水量和气量不能实时显示和控制,洗浴过程中调温困难等等情况。
根据以上情况,设计了合理的燃气热水器恒温控制系统结构:采用8位单片机89S51和DS18B20温度传感器构成温度采集系统的方案,较之采用16位的单片机和热敏电阻加A/D转换器的温度采集系统具有较高的性价比;单片机根据温度传感器采集到的数据,经过程序处理,发送数据指令给0832,通过DAC0832数模转换输出不同的电流来控制燃气比例阀的开度,达到控制火力的大小,实现温度的自动控制;为了提高温度控制精度,采用数字PID程序控制,可实现温度的连续可调,用液晶显示器LCD1602显示出水温度;为加强系统的安全性能,设计中还加入了看门狗和声光报警电路;最后,制作出了工程样板并进行硬件模拟调试。
实际调试结果显示硬件设计基本达到了要求的技术指标,对比分析可知此设备具有良好的应用前景。
关键词:单片机;温度转换; DS18B20 ;DAC0832
ABSTRACT
WITH THE CONTINUOUS PROGRESS AND DEVELOPMENT, PEOPLE ARE INCREASINGLY DEMANDING GAS WATER HEATER. AND NOW MOST OF THE WATER HEATER THERMOSTAT STAGE OR IN THE MANUAL, HOT WATER TEMPERATURE CAN NOT BE REAL-TIME DISPLAY, WATER AND GAS CAN NOT BE REAL-TIME DISPLAY AND CONTROL THE PROCESS BATH THERMOSTAT, ETC. DIFFICULT SITUATION.
ACCORDING TO THE ABOVE, THE DESIGN OF A REASONABLE GAS WATER HEATER TEMPERATURE CONTROL SYSTEM ARCHITECTURE: 8-BIT MICROCONTROLLER 89S51 AND TEMPERATURE SENSOR DS18B20 PROGRAMS CONSTITUTE THE TEMPERATURE ACQUISITION SYSTEM, COMPARED WITH 16-BIT MICROCONTROLLER AND THE THERMISTOR PLUS A / D CONVERTER TEMPERATURE ACQUISITION SYSTEM HAS A HIGH PRICE; MICROCONTROLLER ACCORDING TO THE TEMPERATURE SENSOR TO THE DATA, AFTER PROCEDURES TO MANDS TO THE 0832 DATA, THROUGH THE DAC0832 DIGITAL-ANALOG CONVERTER OUTPUT CURRENT TO CONTROL THE DIFFERENT GAS PROPORTIONAL VALVE OPENING, TO CONTROL THE SIZE OF FIREPOWER TO ACHIEVE AUTOMATIC TEMPERATURE CONTROL; TO IMPROVE THE ACCURACY OF TEMPERATURE CONTROL, DIGITAL PID PROCESS CONTROL, ENABLING THE TEMPERATURE OF THE CONTINUOUSLY ADJUSTABLE, LCD1602 DISPLAY WITH WATER TEMPERATURE; TO ENHANCE THE SAFETY PERFORMANCE OF THE SYSTEM, THE DESIGN WATCHDOG ALSO ADDED SOUND AND LIGHT ALARM CIRCUIT; FINALLY, THE PROJECT PRODUCED A SIMULATION MODEL AND HARDWARE DEBUGGING.
THE RESULTS SHOWED THAT THE ACTUAL HARDWARE DESIGN DEBUG BASICALLY REACHED THE REQUIREMENTS OF THE TECHNICAL INDICATORS, COMPARATIVE ANALYSIS SHOWS THAT THIS DEVICE HAS A GOOD PROSP