ABSTRACT
Saving energy is becoming a trend with the development of intelligent buildings, and the light controlling system is becoming more and more popular. At the same time, the micro-computer control system as the main and core of control system with the development of electronics , it replaces the traditional electronic circuit , and the control system which based on micro-computer had used in the field of intelligent buildings.
This Thesis Describes the design’s principle of the light controlling Method and also describes how the control system runs . In the process of designing , the complying controlling light as the main line , designed the Hardware and the software separately , and finish the goal of controlling light finally . The main controller and slave controller of the control system makes the MSP430 micro-computer and AT89S52 micro-computer as cores . The system can do many jobs, such as communication, controlling and display. The paper describes the designing process of the circuit at length, including: RS485 communication circuit, control circuit of lighting, watchdog circuit, etc. The designing of software mainly includes the several programming, such as PC communication, lamplight controlling, CRC checking.
The functions of the system is: PC program sends commands by 232 communication ,and the host controller controls the brightness of many lights; The control system uses Modbus agreement and adds CRC checking in order to snsuring the accuracy of information ; Users can set commands in the main controller and control the slave controller; Users also can set commands in the slave controller and control the brightness of the light directly. The control system can open the light when there is someone near the light and can close the light when there is nobody near the light automatically by human body detecting module ; The main controller can catch the information of environment outside by AD sampling and controlling the brightness of the light .Based on the function above Mentioned ,the control system can save energy when controlling the brightness of the light .
In the part of finishing project , the Communicating among all kinds of controllers is favorable ; The main controller can control single or all node controllers ; PC can control node controllers through the main controller ; The node controller can open the light when there is someone near the light and can close the light when there is nobody near the light automatically . But the control system also has some deficiency : such as the Program will make mistake when catch the Information about Light intensity of Environment ;The node controller makes mistake easily when given power.
