Arduino RPM Counter & DC Motor Constant Speed Controller 'Optical Tachometer'

Download Circuit Diagram and programming:

Arduino Nano USB-C Type ( recommended):

ESP32 WiFi + Bluetooth Module for iOT Projects (recommended), more IO pins, improved speed, and supports a Lipo Battery:

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This is a Final Year Electrical Engineering Project. Frequency locked loop Dc Motor Speed Controlling. This Project consists of Arduino Uno, Infra red sensor, Variable resistors, tip122, 16x2 LCD, 12v cpu Fan, jumper wires , dc socket and vero boards.

[gennarodurante]

I have put together your DC motor speed controller with RPM feedback.
I am using an optocoupler instead of an IR TX and Rx. I have attached a flag to my motor shaft to interrupt the optocoupler ounce per complete revolution of the motor shaft.
I have modified your code rpm = 60 * 1000 / (millis() - timeold) * rpmcount; to reflect one interruupt per complete revolution of the motor shaft.
After I modified the code and uploaded to Arduino the result is that the motor shaft starts to turn and then stops shortly thereafter before reaching the preset RPM. This cycle repeats forever.
The only code that works is rpm = 30 * 1000 / (millis() - timeold) * rpmcount;, of course, this gives half of the actual RPM of the motor shaft.
The other problem is that once the motor reaches the preset RPM it oscillates around the preset. Thus the RPM is not stable it varies too much around the preset value.
Any ideas would be greatly appreciated.

[BarryBranton]

Awesome! Very good job, Sir. Do you think you will ever make one with a Hall Effect Sensor?

[jagtarsinghsodhi]

Hello sir, I have made this project, but there is problem.RPM value on the display is not constant. It vary continuously. The speed speed of fan is constant but the rpm value is not constant in display.

[koekoe]

Nice, solid work! It's a very interesting! It's very helpful for my school project. Thanks for sharing!
Can you please send me the code?

[MSufi-olzv]

sir its great effort your are helping lot of students i vist your website lot data available but i unable to find hex file for simulation
can you plz send me hex file for proteous simulation of this project

[ny]

Great video .. I was wondering if you could please send me the codes and Thank you in advance...

[jagtarsinghsodhi]

How we can constant the rpm value on display.

[abuobadak]

nice job sir.could you please send me the schematic and codes please.

[gratitudegajanan]

How to make this circuit on breadboard

[sufi-]

Plz send me the hex file for proeous simulation of this project