### Contactless Digital Tachometer using PIC Microcontroller

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:

Thank you Romel for this contribution. If anyone has doubts regarding this project, please use forum.

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#### Conversation

Sun May 20 2018, 10:01 AM
justinb
how to write and execute a program that read the keypad button and display the number on 7 segment on intel8051 at89s52 in assembly language?
Thu May 17 2018, 06:36 AM
HAMZA TAJ
sir iwant to ask about controller of three phase supply by using back to back thyristor instead of triac....will u give me some guideline?
Sat Apr 28 2018, 12:54 PM
ashutosh jain
IR Remote Switch using TV remote (RC5 Protocol) is not working properly. opp1 & opp2 is in problem.plz help
Fri Apr 27 2018, 08:09 PM
@kaiserslautern Post in forum
Wed Apr 25 2018, 07:09 AM
kaiserslautern
Hello everyone, using software uart is a very good idea for a second serial port. Thank you so much. I would kindly like to know how to connect this port to the PC?
Sat Apr 21 2018, 07:50 PM
This is a community site. Feel free to help anyone needing advice
Thu Mar 29 2018, 10:47 AM
Thu Mar 29 2018, 10:45 AM
can any one using dspic30f2010.
Thu Mar 29 2018, 06:03 AM
Neena
can anybody give solar tracking in 8051 using proteus and keil to mail [email protected]
Mon Mar 19 2018, 07:33 PM
sorry bedo.. maybe next time

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Forum Activity
##### Posted By ExperimenterUK
Sat Jun 16 2018, 11:33 PM
hi sir sorry for the late reply sir can we control...
##### Posted By LAMBO
Sat Jun 16 2018, 07:15 AM
hi sir sorry for the late reply sir can we control...
##### Posted By ExperimenterUK
Mon May 14 2018, 10:17 PM
So the main problem is that I am not getting Analo...
##### Posted By ExperimenterUK
Mon May 14 2018, 09:40 PM
Hi sir after checking all the connection i...
##### Posted By Pater
Mon May 14 2018, 05:36 PM
Basically my project is based on Data Acquisition ...
##### Posted By LAMBO
Sun May 13 2018, 02:13 PM
Hi sir after checking all the connection i...
##### Posted By ExperimenterUK
Mon May 07 2018, 07:27 PM
This design should be fine.Choose a frequency betw...
##### Posted By Pater
Mon May 07 2018, 01:28 PM
Sorry for late reply as exams were on,Based on my ...
##### Posted By ExperimenterUK
Thu May 03 2018, 03:32 PM
If the circuit works with a light bulb, the probl...
##### Posted By LAMBO
Thu May 03 2018, 08:04 AM
Hi sir as u mentioned above everthing is working...