MICROCONTROLLER BASED CONTACTLESS TACHOMETER

PROJECT TYPE

Micro controller (AT89C51) based hardware design with

Software development.

PROJECT DESCRIPTION

Aim of the design is to develop a system based on Embedded

micro controller(8051) which is used as a digital contactless

tachometer for measuring the speed(in rpm) of the AC(or) DC motor by

using Infrared Frequency without the help of a expensive tachometer

available in the market.

This project ‘micro controller based contactless tachometer’

design makes use of 8051 micro controller for interfacing to various

hardware peripherals. Technology today is seeing its heights in all the

areas ,especially in the area of Embedded Systems. It is true that every

electronic gadget that is used in daily life right from a PC keyboard to a

refrigerator is an Embedded System. This itself shows how vastly the

technology is expanding.

The current design is an Embedded application which is used to

calculate the speed of the motor without the need of tachometer. In

this application IR frequencies are used to calculate the speed of the

motor. Place the tx and rx in such a way that the IR transmitter

continuously generates the infrared rays and the receiver receives it.

To the motor shaft arrange one circular arrangement having a small

hole and position it exactly at the middle of tx and rx arrangement in

such a way that when the shaft rotates, only at one point the ir rays

falls on the rx.

Now make the motor to run at some speed. As usual the IR

receiver receives the IR signals from the transmitter when the motor

was running for every one complete rotation. The IR receiver(TSOP)

sends these data to the micro controller, the controller compares the

data and calculates the speed of motor. Speed(in rpm) was displayed

on the display unit(LCD). This method of calculating speed is very

inexpensive and cheap when compared to the tachometers available in

the market.

PROJECT OUTLINE

A brief introduction to internal architecture of micro

controller.

An over view of programming of micro controller.

An over view of Embedded C language.

An over view the input devices.

An over view of display unit.

INTERFACES USED

LCD interfacing.

Interfacing with micro controller.

Infrared interfacing.

SOFTWARES USED

A Cross compiler for compiling and linking the code written

for AT898C51.

Serial communication software for downloading code to

AT89C51.

Operating System: Windows 2000.

Application program development in Embedded C.

Block diagram:

MICRO CONTROLER

POWER

SUPPLY

DISPLAY

UNIT

TSOP

555 TIMER

IRTRANSMITTER