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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Mon Jan 16 2017, 03:15 PM
Rutuja
How can we read notepad file using random acess file
Fri Jan 06 2017, 06:18 AM
muhammad Umar
i need cd4047 library file for protious please help me i s
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@Emin what is your site user name ?
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Emin
Emin: I'm already a member since 2012 and entered repeatedly during period. But now it is impossible and obtaining a new registration is also failed. The same error message specifying that two e-mails i entered are different!. In fact thaey are the same. Now, what will be happen, what is your solution? Thanks..
Tue Jan 03 2017, 11:15 PM
Emin
I'm already a member since 2012 and entered repeatedly during period. But now it is impossible and obtaining a new registration is also failed. The same error message specifying that two e-mails i entered are different!. In fact thaey are the same. Now, what will be happen, what is your solution? Thanks..
Sun Jan 01 2017, 03:14 PM
Manoranjana Chary
Write an embedded program of increment and decrement in LCD connected to two keys of int1 and int0. Can u please send me the code for this as fast as possible because i need to submit it in college kindly
ExperimenterUK
Sat Dec 31 2016, 06:28 PM
Happy New Year everyone
ExperimenterUK
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Please post questions in the forum, the chat box is for chat
Thu Dec 29 2016, 07:47 AM
drashti ranolia
can anyone help me for the microcontroller 8051 programming code for street lights that glow on vehicle movement using IR sensors ?
Tue Dec 27 2016, 11:45 AM
Shubhangi
Do we have to write lookup table for d6t thermal sensor?

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sarfrosh92
Sun Jan 15 2017, 09:18 AM
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you are right ..I should not include '\' at t...
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No ,its not the null character, its just the '...
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There is a fault in your Proteus design.If you loo...
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The 8051 Microcontroller (3rd Edition) by I. Scott...
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The site editor may have removed the 0 from \0.Actually it should not be needed, sochar *phone_no[3 ]={"1234567890" ," 9087654321" ,"76676667676"}; //array of pointers should work.
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There is a fault in your Proteus design.If you loo...
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Hi phill sir.. testButton1: ...
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suppose i have this arraychar *phone_no[3 ]={"1234...
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