Embedded System project report

Intoduction to Ebedded System

An embedded system is a computer system designed  to perform one or a few dedicated functions often with real computing constraints. It is embedded as part of a complete devices in day to day life.

        Embedded system are controlled by one or more  main processing cores i.e. typically either a microcontroller or a digital signal processor(DSP). The key feature of embedded system is to handle a particular task, which may require very powerful processors.

for e.g.-Air traffic control,Digital watches,Traffic lights, Metro gates e.t.c

Microcontrollers

• Microcontroller (MC) may be called computer on chip since it has basic

features of microprocessor with internal ROM, RAM, Parallel and serial

ports within single chip. Or we can say microprocessor with memory and

ports is called as microcontroller. This is widely used in washing machines,

vcd player, microwave oven, robotics or in industries

• Microcontroller can be classified on the basis of their bits processed like

8bit MC, 16bit MC.

• 8 bit microcontroller, means it can read, write and process 8 bit data. Ex.

8051 microcontroller. Basically 8 bit specifies the size of data bus. 8 bit

microcontroller means 8 bit data can travel on the data bus or we can read,

write process 8 bit data.

LED

LED stands for light emitting diode. It is a semiconductor light source which are used as a indicator lamp in many devices. when LED circuit are forward bias then electron are able to recombine with the hole,with in the device at the time of recombination energy will be release in form of light i.e. also known as photon. This effect is called electroluminscense and this indicate the colour of light. The LED consists of chip of semiconducter material doped with P&N type material to make PN junction.They are small in size & could be placed on PCB or any other material.

LCD

A liquid-crystal display (LCD) is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals. Liquid crystals do not emit light directly.

Stepper Motor

stepper motor is a device which translate electrical pulses into mechanical movement. It is used for position controling application such as in disk drive in robotics, in printer etc. A stepper motor has a fixed stator and as a movable roter.

A stepper motor has a rotation which are divide into steps. The angle of the motoin is refered as stepper angle. A stepper motor can be used in three modes-

1)wave drive

2)full drive

3)half drive

DC motor

A dc or a direct current motor is used to convert electrical pulses into mechanic force for connecting a dc motor it should be given a dc voltage source  to execute the operation. In dc motor the charaterstics such as speed and exact angle of rotation can not be calculated. However they come with the manufacture standerd of RPM(rotation per minute).