Design And Implementation Of Water Heater Controller For Constant Temperature Based On STM32

Constant temperature water heater is a water heater that can keep the user’s settingtemperature basically invariable when the temperature and pressure of the water infall arechanged. With the raising of our living standard and popularization of household application,water heater is widely used. But users have to adjust the valve to control the water temperature.In most cases, the water temperature is changing, so that you have to adjust the valve again andagain, which is bothering. In order to solve the problems discussed above, the paper proposed anintelligent controller to control the water temperature. According to the temperature set by users,this controller controls the rotation of the motor, which controls the proportion of the hot and coldwater. Then the constant water temperature is solved.Form the angle of the constant temperature shower technology and market development trend,this article developed a constant temperature water heater controller based on STM32microprocessor. The technologys of this controller involveμC/OS-II operating system,μC/GUIGraphic interface system, Touch screen technology and Constant temperature mix water valvetechnology.The conceptual design, design and implementation of the hardware and software for thecontroller systerm is finished in this thesis. Temperature control that is mainly to complete theconstant temperature of the valve is the most important part.Man-machine interface can providethe user interaction with the system.It can mainly complete the temperature setting for users, chiefinformation display, heating time setting and touch screen calibration and so on.The control system that applys for hot water supply system such as water heaters belongs to thetypical household sanitary thermostatic system.The man-machine interface and the stability andthe accuracy put forward higher request for the system.According to the water temperature range,system Chooses DS18B20 as the temperature sensor to design temperature acquisition circuit.Thestepping motor controls constant temperature mix water valve to improve the stability andprecision of the system. Human interaction circuit through the MCU control touch screenrealization. This system chooses low cost, low power consumption of the Cortex-M3 processorsSTM32F103VC as core controller.Software mainly completes the function of the collection of temperature, the user commandinput, mix water valve control information display, storage and data memory, alarm, time settingand display and so on. C language is used to programme with the development tool of KeilμVison4.The main program accomplishes a specific fuction by calling each program module. The sub programmes include initialization of the system peripherals, signal acquisition, commandinput, motor control, data analysis and storage, information display and so on. By using missionsdesign method withμC/OS-II and callingμC/GUI interface function, the system completes abeautiful interface design.This topic is expected to complete the idea. The system hardware circuit is designed andimplemented. The system software is completed to write and debug. Test results meet the designrequirements.