Contactless Digital Tachometer using PIC Microcontroller

Hey friends, I should have posted this project last month itself but there was some problem with the circuit. [link], author of this project did an exellent job. I have been watching him learning on this website. He came as a total noob but now he is well versed with 8051 and PIC microcontroller. earlier he has submitted Microcontroller Based Home Security System



This project is about A Contactless Digital Tachometer. As per defination from wikipedia

A tachometer (revolution-counter, Tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes from Greek Ταχος, tachos, "speed", and metron, "to measure".

wikipedia



Following diagram explains the logic of this project.



The infra red reflective object sensor work by simply emitting the infra red beam and when it encounter the white object surface than the infra red beam will be reflected back to the phototransistor; next the phototransistor and the 2N3904 transistor which formed the Darlington pair will start to conduct and will generate enough voltage across the 470 Ohm resistor to be considered by the PIC16f690 microcontroller build in Capture Compare Pulse width modulation(CCP )module input port as the logical "1". When the infra red beam encounters the black tire surface than both of the phototransistor and 2N3904 transistor will turn off; and the voltage across 470 Ohm resistor will drop to 3.5 volt (logical "0").

Therefore by timing the generated pulse period by the infra red reflective object sensor we could easily calculate the RPM using this following formula:

Frequency = 1/T Hz; T is the generated pulse period in second.

RPM (Rotation per Minute) = Frequency x 60

Here is a sample video of working project:



You can download project related files here:

Download Contactless Digital Tachometer project

Thank you Romel for this contribution. If anyone has doubts regarding this project, please use forum.
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Wed Sep 20 2017, 12:36 AM
Ted
In a missing pulse detector using a 555 timer connected as a monostable vibrator with a PNP transistor,how does the positve input pulse turn on the PNP transistor?
Sun Sep 03 2017, 02:29 PM
martymarty
How do I connect an <NOKIA 1100 LCD > to an atmega328P ?
poojab51296
Sun Aug 20 2017, 10:23 AM
i am intending to interface sd card with STM32F4 and want to write a file in sd card using SPI protocol but using HAL only. Can anyone help me PLEASE!!!!
poojab51296
Sun Aug 20 2017, 10:22 AM
hello
rawat742
Fri Aug 18 2017, 11:37 AM
hi @ angel patel i will attach a file i hope it will be helpfull for you
ExperimenterUK
Mon Aug 14 2017, 09:57 PM
@ angel patel... just log in and post your problem
Mon Aug 14 2017, 01:45 PM
angel patel
hey any one help to make the led scrolling display
desuza6
Sat Jul 29 2017, 07:09 AM
I see the code for step motor h l 298 to rotate 45 degree, but all delay time, if I want to input sensor to h the pulses to stepmotor
rammichael
Thu Jul 27 2017, 12:05 PM
okay fine
ExperimenterUK
Wed Jul 26 2017, 07:51 PM
Please post questions in the forum, the chat box is for chat

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Cryterion
Fri Sep 22 2017, 05:42 PM
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Sat Sep 02 2017, 01:48 AM

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Posted By bask185
Mon Sep 25 2017, 06:38 AM
I might have a difficult question.At work we build...
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Posted By ExperimenterUK
Thu Sep 21 2017, 01:33 AM
You could start with this tutorialhttp://www.8051p...
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Posted By komal_97
Wed Sep 20 2017, 12:25 PM
hey, i want to interface 3 dc motors with the micr...
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Mon Sep 11 2017, 12:07 AM
The hardware for connecting to a PC or a modem is...
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Posted By Suseethra
Sat Sep 09 2017, 09:43 AM
Hi,we are doing the same project(LED scrolling dis...
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Posted By ExperimenterUK
Mon Aug 28 2017, 07:21 PM
First you have to decide which version of the 8051...
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Dear Sir, I want to purchase progra...
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Debuggers and programmers are different things.Whi...
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Dear Sir, if I am not purchase debugger then how ...
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I am using STM32 cube MX and Atollic truestudio so...