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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Comments

ketan.avpti
Thu Apr 24 2014, 02:30 AM
Nishant519
Thu Apr 24 2014, 01:40 AM
steve_yu_chan
Wed Apr 23 2014, 12:14 PM
dsk752dsk
Wed Apr 23 2014, 11:46 AM
gdeepkeyrun
Wed Apr 23 2014, 09:25 AM
oneblade
Mon Apr 21 2014, 01:59 PM
trevon22
Mon Apr 21 2014, 11:34 AM
quanyixin
Mon Apr 21 2014, 08:05 AM

Conversation

Wed Apr 23 2014, 02:57 AM
NAD
hi can someone help me write the code to interface an alphanumeric keypad to pic16f877A??!
Wed Apr 23 2014, 02:56 AM
NAD
hi,
kram.ram420
Mon Apr 21 2014, 09:27 AM
Hi.. Please help me to get through microcontrollers..
Sun Apr 20 2014, 05:23 AM
ARPAN
HELLO. I AM USING 8051 WITH RFID , PASSWORD AND FINGERPRINT.I HAVE SFM 3030 FINGERPRINT MODULE HOW TO INTERFACE IT WITH 8051? DIRECTLY OR EXTRA CIRCUITRY IS REQUIRED?AND HOW TO USE TWO SERIAL DEVICES RFID AND FINGERPRINT WITH ONE 8051?
ExperimenterUK
Thu Apr 17 2014, 01:23 PM
@mba Great .. please do.
Thu Apr 17 2014, 12:27 AM
mba'
like the forum and wish to participate
ExperimenterUK
Wed Apr 16 2014, 04:45 PM
@viniciusheidrun..you should read my comment just before your post
viniciusheidrun
Wed Apr 16 2014, 01:43 PM
I'm doing a drive system with SIM900D modem and microcontroller AT89S52 via sms. I'm having trouble can not generate the. Hex to send to the microcontroller, whenever I compile the error, I'm using MCU 8051 IDE, what should I do so that my system receive sms and perform my task?
ExperimenterUK
Mon Apr 14 2014, 01:00 PM
@Haranadh,bipin chandra etc. Create threads for your questions.
Sun Apr 13 2014, 04:05 AM
Haranadh
we bought HC 06 Bluetooth modem instead of Module ,Can any one help me of using it as bluetooth module since i am doing this project?
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