Study On Embedded Smart Home Controller And Development Of Homenet

With the infiltration of intelligence into the household appliances and the rapid development of informatization, the demand of intelligence in home has increased considerably, and eventually led to the birth of smart home and made it improving. The access to the smart home control is mainly through the controllers. Smart home controller consists of a master controller and the slave control modules. The master controller connects Ethernet and the slave control modules; the salve control modules gather environmental data and control terminal equipments.Though the analysis of several control programs which have existed, and on the premise that without affecting the system's function, we design a smart home system based on the RS485 bus. The system has an independent controller that connects to the Ethernet without depending on home computer. It uses the RS485 bus to connect the control modules and use the standard communication protocol. So make the system widely to use and the structure simple and the development cycle short. Most smart home systems are designed for the products that have made. Not only increase the difficulties of control, but also bring troubles to users. For that, this paper designs a low-cost, low-power, standardized system for home appliance manufacturers, who embed the control module into the household appliance, just leaving an interface.This paper completes the hardware designs of the master controller and the slave control modules as well as sets up a homenet and accomplishes the simulation control of running modes of air conditioner, water heater and security monitoring. The master controller uses 32-bit ARM LPC2368 as the core unit. Its peripheral circuits mainly include: circuit of RS485 bus driver, which composed by the MAX3088; circuit of Ethenet, which composed by network controller that integrated in LPC2368 and the physical layer chip DM9161. The household appliance module uses AT89C2051 as the core unit. Its peripheral circuits mainly include: circuit of RS485 bus, circuit of relay driver. The security monitoring module uses AT89S52 as the core unit. Its peripheral circuits mainly include: circuit of RS485 bus, circuit of camera, which composed by the image sensor OV7141. The master controller and the salve control modules are connected through the RS485 bus to compose the homenet.In order to ensure the access between terminal modules and master controller without conflicts, the design uses the perfect Modbus communication protocol, which based on the RS485 bus. The software of modules is designed. The flow charts of software and structures of the communication protocol frames are introduced.