04-09-2012, 12:15 PM
Implementation of Electrical Appliances Control using Microcontroller AT89S52.
mplementation of Electrical.docx (Size: 1.33 MB / Downloads: 61)
Introduction
An embedded system is a computer system designed to do one or a few dedicated and/or specific functions often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs. Embedded systems control many devices in common use today.
In contrast, a microcontroller not only accepts the data as inputs but also manipulates it, interfaces the data with various devices, controls the data and thus finally gives the result.
All these tasks are possible with the microcontroller because the microcontroller has a CPU in addition to a fixed amount of RAM, ROM, I/O ports and timer all on a single chip. This fixed amount of RAM, ROM and number of I/O ports in microcontroller makes them ideal for many applications where cost and space are critical.
Project Overview
Now-a-days, it became very difficult to know that an accident has occurred and to locate the position where it has happened. It’s very difficult for the lives of victims until anyone noticed and informed it to the ambulance or to any hospital and if it occurs in remote areas there will be no hope to survive. To overcome these, GSM and GPS technologies are used. The GPS based vehicle accident identification module contains a vibrating sensor and a GPS modem connected to the microcontroller. When an accident occurs, the vibration sensor gives the signal to the microcontroller, which sends the information to the LCD display through GSM network. The vehicle is tracked for every five minutes using GPS and the position of the vehicle is also send to the mobile in terms of latitude and longitude which is processed by the pc.
EMBEDDED SYSTEMS
Description of embedded systems
An embedded system is a computer system designed to perform one or a few dedicated functions often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs. Embedded systems control many devices in common use today.
Embedded systems are controlled by one or more main processing cores that are typically either microcontrollers or digital signal processors (DSP). The key characteristic, however, is being dedicated to handle a particular task, which may require very powerful processors. For example, air traffic control systems may usefully be viewed as embedded, even though they involve mainframe computers and dedicated regional and national networks between airports and radar sites. (Each radar probably includes one or more embedded systems of its own.)
Since the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability and performance. Some embedded systems are mass-produced, benefiting from economies of scale.
Advantage of microcontrollers
• If a system is developed with a microprocessor, the designer has to go for external memory such as RAM, ROM or EPROM and peripherals and hence the size of the PCB will be large enough to hold all the required peripherals.
• But the microcontroller has got all these peripheral facilities on a single chip so development of a similar system with a microcontroller reduces PCB size and cost of the design.
• One of the major difference between a microcontroller and a microprocessor is that a controller often deals with bits, not bytes as in the real world application, for example switch contacts can only be open or close, indicators should be lit or dark and motors can be either turned on or off and so forth.
• The Microcontroller has two 16-bit timers/ counters built within it, which makes it more suitable to this application since we need to produce some accurate timer delays. It is even more advantageous that the timers also act as interrupt.
Introduction to AT89S52
It belongs to 8051 family microcontrollers which is based on architecture which is highly optimized for embedded control systems. It is used in a wide variety of applications from military equipment to automobiles to the keyboard on PC.
The AT89S52 is a low-power, high-performance CMOS 8-bit microcomputer with 4K Bytes of Flash programmable and erasable read only memory (PEROM). The AT89S52 is a powerful microcomputer, which provides a highly flexible and cost-effective solution to many embedded control application.