Microcontroller Based Contactless Tachometer

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:

DISPLAY UNIT POWER SUPPLY TSOP

MICRO CONTROLER

555 TIMER

IR TRANSMITTER