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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Conversation

Thu May 21 2015, 01:04 AM
utpal
i am a hobbist. i work on 8051. just i have started with pic 16f877. but a bitter experiance is going on. as i am programming any code to my pic877 and putting it in my board and it is working, but the 2nd time it is not taking any program,I have experimented just 7 new one pic mcus. result is the same. please tell me the reason. my programmer is TOP3000(universal programmer).
ajay_bhargav
Wed May 20 2015, 04:48 AM
@lak you can use the same code provided you are not using any s52 specific ports and registers.
Mon May 18 2015, 05:58 AM
lak
i used to develop a code for at89s52 shall i use the same code for at89c4051
Sun May 17 2015, 07:57 AM
Ayoosh
what if i have to rotate motor continuously at a step angle of 1.8 degree
ExperimenterUK
Fri May 15 2015, 06:02 PM
@oracle1946.. Post your question in the PIC forum
Fri May 15 2015, 03:48 AM
nadeem232
if some has solution kindly share solution Principles of Electric Circuits,by Thomas L. Floyd
oracle1946
Thu May 14 2015, 03:39 PM
I want to build a PIC16F684 sun logger using either a solar cell (0.5v solar cell or photoresistor). Any help out there?
Thu May 14 2015, 11:59 AM
Ramprasad Malviya
please sir send me moving led display programming in asm&c language
ajay_bhargav
Thu May 14 2015, 04:43 AM
@bach please post in forum and let us know which software are you using
Tue May 12 2015, 10:25 AM
bach
hi guys, im kinda new to all of this. im looking for a splice model of the l293 IC and would be very appreciative if someone can point me in the right direction.

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Comments

as_rog
Sun May 17 2015, 08:00 AM
oracle1946
Thu May 14 2015, 03:34 PM
kakaru32
Tue May 12 2015, 04:29 PM
Yateesh
Sat May 09 2015, 02:46 AM
scmg
Fri May 08 2015, 06:40 PM
OMERO
Fri May 08 2015, 11:53 AM
Carlos55
Fri May 08 2015, 02:14 AM
osman6464
Thu May 07 2015, 02:38 PM

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mayank058 Avatar
Posted By mayank058
Thu May 21 2015, 04:46 AM
dear sir there is nothing to zip.I just...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed May 20 2015, 04:57 AM
can you zip your complete project and attach it he...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed May 20 2015, 04:46 AM
If you know how to drive 7-seg using an 8-bit port...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed May 20 2015, 04:42 AM
There was no proteus file included in the package,...
ankitbajaj01 Avatar
Posted By ankitbajaj01
Tue May 19 2015, 07:00 AM
Hello ExperimenterUK...Please guide me on above po...
mayank058 Avatar
Posted By mayank058
Tue May 19 2015, 04:54 AM
Sir I want to measure the analog signal on CRO.
ElectronicManiac Avatar
Posted By ElectronicManiac
Mon May 18 2015, 07:52 PM
There was no proteus file included in the package,...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon May 18 2015, 04:16 PM
Does the speaker work?.'Exactly' where on the boa...
mayank058 Avatar
Posted By mayank058
Mon May 18 2015, 06:01 AM
dear sir, when I use your code on the...
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Posted By Rakesh_suthar
Sun May 17 2015, 05:42 AM
hi ,I am working rtc by avr with seven segment .bu...