element14 Community
element14 Community
    Register Log In
  • Site
  • Search
  • Log In Register
  • Community Hub
    Community Hub
    • What's New on element14
    • Feedback and Support
    • Benefits of Membership
    • Personal Blogs
    • Members Area
    • Achievement Levels
  • Learn
    Learn
    • Ask an Expert
    • eBooks
    • element14 presents
    • Learning Center
    • Tech Spotlight
    • STEM Academy
    • Webinars, Training and Events
    • Learning Groups
  • Technologies
    Technologies
    • 3D Printing
    • FPGA
    • Industrial Automation
    • Internet of Things
    • Power & Energy
    • Sensors
    • Technology Groups
  • Challenges & Projects
    Challenges & Projects
    • Design Challenges
    • element14 presents Projects
    • Project14
    • Arduino Projects
    • Raspberry Pi Projects
    • Project Groups
  • Products
    Products
    • Arduino
    • Avnet & Tria Boards Community
    • Dev Tools
    • Manufacturers
    • Multicomp Pro
    • Product Groups
    • Raspberry Pi
    • RoadTests & Reviews
  • About Us
    About the element14 Community
  • Store
    Store
    • Visit Your Store
    • Choose another store...
      • Europe
      •  Austria (German)
      •  Belgium (Dutch, French)
      •  Bulgaria (Bulgarian)
      •  Czech Republic (Czech)
      •  Denmark (Danish)
      •  Estonia (Estonian)
      •  Finland (Finnish)
      •  France (French)
      •  Germany (German)
      •  Hungary (Hungarian)
      •  Ireland
      •  Israel
      •  Italy (Italian)
      •  Latvia (Latvian)
      •  
      •  Lithuania (Lithuanian)
      •  Netherlands (Dutch)
      •  Norway (Norwegian)
      •  Poland (Polish)
      •  Portugal (Portuguese)
      •  Romania (Romanian)
      •  Russia (Russian)
      •  Slovakia (Slovak)
      •  Slovenia (Slovenian)
      •  Spain (Spanish)
      •  Sweden (Swedish)
      •  Switzerland(German, French)
      •  Turkey (Turkish)
      •  United Kingdom
      • Asia Pacific
      •  Australia
      •  China
      •  Hong Kong
      •  India
      •  Japan
      •  Korea (Korean)
      •  Malaysia
      •  New Zealand
      •  Philippines
      •  Singapore
      •  Taiwan
      •  Thailand (Thai)
      •  Vietnam
      • Americas
      •  Brazil (Portuguese)
      •  Canada
      •  Mexico (Spanish)
      •  United States
      Can't find the country/region you're looking for? Visit our export site or find a local distributor.
  • Translate
  • Profile
  • Settings
Arduino
  • Products
  • More
Arduino
Arduino Forum RPM measurement from a motor tachometer
  • Blog
  • Forum
  • Documents
  • Quiz
  • Events
  • Polls
  • Files
  • Members
  • Mentions
  • Sub-Groups
  • Tags
  • More
  • Cancel
  • New
Join Arduino to participate - click to join for free!
Actions
  • Share
  • More
  • Cancel
Forum Thread Details
  • State Not Answered
  • Replies 14 replies
  • Subscribers 417 subscribers
  • Views 3878 views
  • Users 0 members are here
Related

RPM measurement from a motor tachometer

e14 Contributor
e14 Contributor over 13 years ago

Good Day,

 

     I'm currently doing a project involving wirless speed control and speed monitoring devices using an Arduino ATMEGA644.

The sensor I'm using is a unipolar hall switch which turns on with the presence of a magnetic field. The sensor generates a

waveform relative to the speed of the motor. I can calculate the speed in terms of RPM by multiplying 60 to the frequency of

the generated waveform. I'm aware that the signal must be an analog input but I don't know how to code my arduino for it to

be able to calculate the frequency generated as well as the RPM speed of the motor. I badly need your help.. Anyone who

can answer my question??

  • Sign in to reply
  • Cancel

Top Replies

  • e14 Contributor
    e14 Contributor over 13 years ago +2
    Hi Edd Niel, To do motor speed measurement, you need little more intermediate knowledge of Arduino. There are two ways you can do this. 1. use the Arduino function pulseIn() and count the pulses in 1 second…
  • Workshopshed
    Workshopshed over 13 years ago in reply to e14 Contributor +1
    Here's a couple of places with examples for interupts. http://tronixstuff.wordpress.com/tutorials/ http://www.engblaze.com/we-interrupt-this-program-to-bring-you-a-tutorial-on-arduino-interrupts/ This…
  • shabaz
    shabaz over 13 years ago in reply to Workshopshed +1
    The interrupt approach is very ideal. Just for the rare cases where a different method may also be needed: another way (slightly more analog!) is to just take the pulses from whatever sensor is generating…
  • mcb1
    0 mcb1 over 13 years ago in reply to billpenner

    re Optical mice.

     

    Be aware they are usually a 38Khz signal between the led and sensor to eliminate any stray light.

     

    mark

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • billpenner
    0 billpenner over 13 years ago in reply to mcb1

    Mark:

    Thanks for the comment I didn't know that the LED was pulsed at that rate on a mouse sensor. However, I was refering to a digital tachometer such as below.

     

    Edd Niel Tabudlong

    This link will take you to the one I have. I am very happy with the results. This could probably be hacked, but I suggest it only for reference.

     

    http://www.google.com/shopping/product/9074361313685627858?

     

    Here is another link you might find useful.

    http://www.pyroelectro.com/tutorials/tachometer_rpm_arduino/img/schematic.png

     

    Bill

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • e14 Contributor
    0 e14 Contributor over 13 years ago in reply to billpenner

    thanks for your suggestion sir...i get the point and in fact i've already tried using CNY70 ir sensor.. but my problem now is on how can i send this tach reading from 1 arduino to another via serial wireless communication. the arduino with tach is the same arduino receiving the command of which speed level the user transmit. knowing that the tach reading is constantly updating at a matter of second, signals might bump if a user from the other arduino transmit a command. any idea sir how can i incorporate my tach code to my existing speed control code in 2 arduino's communicating wirelessly?

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • billpenner
    0 billpenner over 13 years ago in reply to e14 Contributor

    Sorry I cant help you with RFID. Please ask another question regarding RFID polling.

    Bill

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
<
element14 Community

element14 is the first online community specifically for engineers. Connect with your peers and get expert answers to your questions.

  • Members
  • Learn
  • Technologies
  • Challenges & Projects
  • Products
  • Store
  • About Us
  • Feedback & Support
  • FAQs
  • Terms of Use
  • Privacy Policy
  • Legal and Copyright Notices
  • Sitemap
  • Cookies

An Avnet Company © 2026 Premier Farnell Limited. All Rights Reserved.

Premier Farnell Ltd, registered in England and Wales (no 00876412), registered office: Farnell House, Forge Lane, Leeds LS12 2NE.

Follow element14

  • X
  • Facebook
  • linkedin
  • YouTube