Research And Design Of Embedded Smart Home Control System Based On Linux

With the improvement of people's quality of life,the needs of people's home security and intelligence is getting higher and higher.It has became a trend to combine home security,home intelligence and home communications with network facilities.Currently,Smart home is a hot area which is closely related to people's lives.Embedded system and wireless communication are new methods for information processing and information acquisition.And they are also an important part of smart home.It has great practical significance to use embedded system and wireless communication to complete the design of smart-home control system which can realize the acquisition of home environment information,the control of electrical appliances and monitoring of home security.The smart-home control system in this paper mainly includes four parts: terminal device,coordinator device,ARM controller,and mobile phone client.The home environment information data acquired by terminal device are transferred to mobile phone client to display through ZigBee wireless network and ARM controller.At the same time,the user can control the work of home electrical appliances by clicking the button of the mobile phone client.At present,many household air conditioning are controlled by infrared remote controllers.The disadvantages of infrared remote controller's are that they must be aligned with air conditioning and their communication distances are also very short.These may bring a lot of inconvenience to the user,so this paper redesigns an air conditioning control module to improve these shortcomings.The module realizes the function to control air conditioning through home wireless network,which overcomes the shortcomings of traditional remote controllers.It also has the ability to learn the control commands of infrared remote controller,so it can control different kinds of air conditioning.The main works are as follows:First,we investigate and research kinds of the device module models of terminal device.The paper uses DHT11 and MQ-2 to collect home environment information,uses HC-SR501 for home security monitoring,uses relays to control the electric switch.Terminal device can accomplish the acquisition of home environment information,the control of electrical appliances and monitoring of home security by controlling these modules.Second,the hardware and software of the system is designed.On the one hand,a terminal device with low power consumption and excellent response performance is designed and implemented.The circuit of the terminal device is mainly include the interface circuit of the CC2530 baseboard and interface circuit of other modules.The terminal device uses the CC2530 chip as it's processor.The CC2530 baseboard uses the low-power,close-range ZigBee protocol for wireless communications.In order to make the system have a good responsiveness,the retransmission request of error and the response of successful reception are added to it's software design.The terminal device realizes the functions of reading data of the sensor module,controlling the light,the motor,the relay and the control module of air conditioning,and joining the coordinator network.The circuit of the coordinator reuses the circuit of the terminal device.In order to make the system have a good response capability,the retransmission of data error and timeout is added to it's software design.The coordinator realizes the establishment of ZigBee wireless network,and the function to communicate with the ARM controller.On the other hand,an air conditioning control module with low power consumption and practicability is designed and implemented.The module overcomes the shortcomings of traditional infrared remote controller.The air conditioner control module can learn infrared remote control code and send the remote code to air conditioning through infrared receiving and sending circuit.Third,the hardware and software of ARM controller are designed.This paper uses S3C2440 processor with low power consumption and fast speed,and Linux system with easy cutting and small kernel to realize the design of ARM controller.And a TCP server is designed for ARM controller to realize the communication between ARM controller and mobile phone client as well as the communication with coordinator.A manmachine interaction interface is designed for mobile phone which realizes the display of home environment information such as temperature and humidity,gas concentration status,and light status as well as the control of lights and curtains by clicking on the interface button.Fourth,the smart home control system is tested for power consumption and function,including terminal equipment power consumption test,air conditioning control module power consumption test,temperature and humidity sensor data acquisition test,temperature and humidity monitoring test,light control test,ARM controller server communication test,system response capability test,air conditioning control test,and mobile phone client test.After testing the temperature and humidity monitoring,light control functions,ARM controller functions,mobile phone client functions,the system can normally complete the collection of family environment information through wireless network,upload it to the mobile phone terminal for display,and control the work of household electrical appliances such as lights through the mobile phone client.Through testing the power consumption of the terminal equipment circuit board,the power consumption of the air conditioning control module circuit board,the data acquisition of the temperature and humidity sensors,the system response capability and the air conditioning control,it is concluded that the current consumption of the terminal circuit board is relatively low with an average current of 26.14 mA,and the power consumption of the air conditioning control module is very low with an average current of 2.7mA which meets the requirements of the system.The accuracy of DHT11 temperature and humidity data is as high as 98%,the response rate of the system wireless communication is as high as 98.7% within 60 m,and the distance of 70 m is as high as 76.7%.The response capability is very good,which meets the system requirements.The system realizes air conditioning control through the redesigned air conditioning control module.The success rate of air conditioning control in different directions within 50 m reaches 95%,which is effectively improving the shortcomings of the traditional infrared remote controller that the communication distance is short and must be aligned.It is convenient to use to a great extent and meets the requirements of the system.The above tests verified the correctness of the system's overall functional design and the excellence of the system's response capability.