In this competitive world and busy schedule human cannot spare more time to perform his daily activities manually. This project is a standalone PC based Hi-tech home implementation using AT89S52 microcontroller. This project is useful in all applications where automation of electrical appliances is required. Use of embedded technology makes this closed loop feedback control system efficient and reliable. Microcontroller (AT89S52) allows dynamic and faster control. AT89S52 micro controller is the heart of the circuit as it controls all the functions.
The main aim of this project is to control various electrical appliances by means of PC using PC’s hyper terminal window. The person sitting in front of the PC can continuously check the loads being operated in the rooms and can switch off them wherever not required just by sitting in front of his PC. The controlling of loads is done by TRIAC. The main advantage of using a TRIAC to vary the status of loads is the TRIAC reduces the energy flow to the loads and TRIAC works very well for alternating currents.
In order to control the electrical appliances through PC, data transfer must be ensured between PC and 8051 system. Serial data communication uses a single data line which makes it not only cheaper but also enables two computers located in two different cities to communicate over the telephone. There are special IC chips made by many manufacturers for serial data communication. These chips are usually referred to as USART(Universal synchronous-asynchronous receiver-transmitter) and UART(Universal asynchronous receiver-transmitter). 8051 chip has an in-built UART i.e., it has an integrated serial port which enables one to read and write values to the serial port very easily.
The rate of data transfer in serial data communication is stated in bps (bits per second) or baud rate. To allow data transfer between PC and 8051 system without any error, the baud rate of the 8051 system should match the baud rate of the PC’s COM port. Thus the operation mode and baud rate of the serial port is to be configured. Once configured, read or write operations can be performed accordingly.
SOFTWARE AND HARDWARE TOOLS:
Software Tools:
- Keil compiler
- Orcad.
Hardware Tools:
- Microcontroller AT89S52.
- PC
- MAX232
- LED array
- TRIAC and TRIAC driver
BLOCK DIAGRAM
