Chris @ PyroElectro.com writes:
A tachometer is a useful tool for counting the RPM (rotations per minute) of a wheel or basically anything that spins. The easiest way to build a tachometer is using a transmitter and receiver. When the link between them is broken, you know that something is spinning and can execute some code that calculates the current RPM of whatever is spinning to break the transmitter/receiver link.
In this article we will explore how to use an IR transmitter and receiver break-beam pair similar to the PIC Tachometer project I built a few months ago, but because of popular demand, the Arduino system will be used for all the processing and break-beam interruption counting. The end result will be a 16×2 LCD displaying the RPM of some computer fans.
Arduino Tachometer - [Link]
I’m really very happy to present this circuit! This is a very special page, and what’s special about it is that this circuit is designed NOT by me, but from a PCB Heaven reader, which happens to be also one of my students in my PIC classes. As a matter of fact, he is my first student… Well, ok, he is my only student :). So, this is the very first circuit page that i host in my site which is designed by a PCB Heaven reader. Special thanks to Panagioti Kalogeri, which you will find him trolling around my site with the id _Pike…
This circuit is the result of an exercise that i asked him to make, in order to practice with the Timer modules of the PIC. The PIC will read the tacho output of a PC fan. The rpm is then translated into a number of LEDs turned-on on the bar-graph. The minimum rpm during which only one LED is turned on is 600 rpm, and the maximum is 1200 – which is also the max speed of the fan. Panagiotis was asked to implement the rpm measurement with the Reverse Frequency Measuring as described here.
PC Fan RPM Bargraph Meter with PIC - [Link]
quipped with sophisticated Enhanced Capture/Compare/PWM (ECCP) peripheral the Microchip PIC18F14K50 microcontroller could produce up to four PWM channels output. The enhanced PWM (Pulse Width Modulation) mode in ECCP peripheral is capable to drive the full bridge DC Motor circuit directly both in forward or reverse direction. It also could generate single PWM output on the selectable PIC18F14K50 pins when it configured in pulse steering mode. In this tutorial we will take advantage of PIC18F14K50 pulse steering mode to drive the DC Motor and at the same time we will build the RPM (Rotation per Minute) counter to observe the PWM effect on the DC Motor speed and display it on the 2×16 LCD.
PIC18 Pulse Width Modulation (PWM) DC Motor Speed Controller with the RPM Counter Project - [Link]
This is a very basic lesson on how to make a contact-less digital tachometer using infrared light reflection technique. It can measure RPM up to 99960 and the resolution is 60 RPM.
How to make a contact-less digital tachometer using IR-light reflection technique – [Link]
This is a small, off-the-shelf, DIY digital tachometer that uses a photo-interruptor (IR emitter/detector) to keep track of the RPM of anything. It’s a simple yet very effective design that I thought you might like. The RPMs of a desktop computer fan are tracked as an example with this system.
Build A Digital Tachometer / RPM Counter – [Link]
This article shows how to convert a servo into and geared motor.
But, you still want the RPMs of a servo without the hassle of the pulsing control. So, you hack the servo and make it a geared motor. Easy! Here’s how…
Turn a Servo Into an Inexpensive Geared Motor – [Link]
The OBDuino is an in-car real-time display of various information, like speed, RPM, instant fuel consumption or average trip fuel consumption as well as others PIDs supported by the car. It reads the data from the car’s OBD-II connector, interfacing it via a MC33290 chip to the Arduino which processes the CAN data and outputs to a 2×16 LCD. [via]
OBDuino: car diagnostics with Arduino - [Link]
Tachometer is used to measure the rotational speed of any shaft or disc. The unit of the measurement is rotation per minute or just RPM. This project describes a contact-less tachometer based on PIC16F628A microcontroller. The rotation of a disc is measured through a set of IR module that converts one complete rotation into a pulse. The result is displayed in a multiplexed seven segment display.
Contact-less Tachometer using PIC16F628A Microcontroller – [Link]
ikalogic.com just finished IKA-TACH project which is a contactless Tachometer based on ATMEGA48 AVR micro controller. Detection of rotation is done using a IR transmitter / receiver module. There is also a red led that helps point the invisible IR led. This tachometer is able to measure both low RPM speed and high RPM speed. Check construction details and KIT on the link below.
IKA-TACH: DIY Contactless Tachometer - [Link]
This project shows an 3-Wire DC Fan rpm regulator with intelligent duty cycle adjustment. The circuit will try to maintain the preselected rotation speed by adjusting duty cycle and receiving feedback from fan output. Check full project details on the link below.
PIC 3-Wire Fan RPM Controller - [Link]