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A very simple way to make a tachometer where the result is displayed on an OLED display in the form of an RPM number and a progress bar for greater visibility.


- Arduino Nano R3
- SH1106 od SSD1306 Oled display 128x64
- Cheap Infrared sensor module

A tachometer 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 Analogue dial, or on digital display. In this project, tachometer is made using an IR Sensor module as unit for measuring the number of rotations.

Simply we have interfaced the IR sensor module with Arduino nano and the SH1106 Oled display. The sensor module consists of IR Transmitter & Receiver in a single pair that can work as a Digital Tachometer for speed measurement of any rotating object.

One diode transmits IR rays which reflect back to the receiver diode and then IR Module generates an output or pulse which is detected by the Arduino controller.

Arduino calculates RPM for a minute using the given formula:

rpm = (objects / 3.0)*60;

because in our case we have 3 obstacles (objects) in one full circle”

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