Super simple Arduino Frequency Counter 

Nice simple, but useful little project! Thanks! I built it on a full size breadboard with a breadboard power supply and built a 555 a stable oscillator on the other end. Fun to experiment with capacitor and resistor values and see the instant results.

Thanks to you i found a use for one of my arduinos. I made slight changes so i could use it on a 16x2 lcd screen and hocked that baby up to my adjustable computer clock. Now i can finally exactly see on which frequency im running

I made a USB current/voltage meter by using the same OLED+Nano and a shunt resistor. The arduino has an internal voltage reference, which I used to scale the analogRead voltage.

Always amazed at the Arduinos capabilities.

I kept working from your orignal project and it does measure AC sine wave without issue. Question was how to get from 120VAC to 10VAC. I purchased a standard door chime transformer (U.S.) that drops 120VAC to 24VAC/16VAC/8VAC for $14.00 at Home Depot and added (2) 1/4W 20K resistors to both the plus and minus connections to keep the current draw down - presto measures 60Hz. My problem solved. Thanks for posting your early efforts, It helped me solve my issues for my project.

Nice little project! Useful too. Keep 'em coming...

This is great! I'm going to tweak it to run on the Sparkfun Microview!

Hall effect sensor with a 4 or 2 magnet collar to measure shaft rotation speed.

Amazing Video! This helped a ton at work!

Cool. I'm gonna use it in my water flow meter project.

I think I will add this to my 50 ohm RF dummy load I am currently building maybe add an output power meter as well. Now you got my juices flowing. I'll never get to bed now.

Carry on! Love that series of movies, I have the most of them in my collection, and not a night has gone by since I have received them that I have not watched at least one of them. Last night's movie' Carry On Regardless!

This is great. I did it with s bare bones arduino on a circuit card with a breadboard buddy PS and put it in a plastic box 3.75" by 2.25". Checked with my oscilloscope, it is indeed acurate.

this only work for square wave signal. it really is piece of cake. thank you so much.

Big problem, you fed it a signal from function generator that was not offset to meet input range of a pin, 0 - 5. Your input swings below ground. Thats a great way of burning out chip. You need to add an R divider to bias up input, Vdd >> R >> pin >> R >> ground. Then capacitor couple input signal to the pin. The Rs around 1K or less. In your example with 50 ohm generator, you swung -2.5 V across pin, thats about 50 mA you drove into pin. Not a good idea.

Very Useful Thank You

I'll have to try this in my portable Arduino box. Since I switched up to the ESP chips for my EMF detector v2, it's been neglected! Exact same hardware in a 3d printed small handheld using a fat 18650 battery.

Muito bom , bem simples e funcional , Obrigado !

Thanks for the video! Is there a way to be able to make this an elektroslush as well as the frequency counter? Any help on doing so would be greatly appreciated

do i still write FreqCount.begin(1000); to start the count or do i use something else? im not well versed in this so sorry if i am asking obvious things would it be something like FreqMeasure.begin(1000); ?

Very nice and helpfull. Thanks for the video.

Very nice project! Can this be done with radiofrequency too? I mean, make something like a fequency counter to measure the working freq. Of a garaje door key for example? Thanks!

Could you please suggest me a way to deal with a crystal oscillator resonance frequency? Because I'm willing to make a microbalance by removing the metallic part of the crystal oscillator. The change in the resonance frequency of the crystal oscillator when external thin film of material deposited on the oscillator will take into account. So is their a way to count that resonance frequency with Arduino due? Anywhere to look at? Thanks.

Amazing video thank you. Could this be converted to rf? i.e to measure the frequency output of a metal detector coil for instance? Maybe adding a coil say 50mh?

Hi thanks for sharing this valuable application. I am wondering if you could demonstrate: using ultrasonic detector (read only) and print out the frequency the detector receives from a ultrasound source such as a broken bone/metal/adhesive or anything that can generate ultrasound wave when broken.... thanks.

Good job!!

Hello, great project. What is the maximum frequency that can be measured (Square wave). Thank you.

Nice! I'd add an input buffer/amplifier and voltmeter then it would make a great display for a homebuilt function generator, showing the frequency and amplitude.

Nice work! Would it work with sinus?

Like Thanks, I'm going to give it a go. I'm also going to jam it in a Tiny85 and see what happens.

Hi sir it posible to check frequensi 100khz until 150khz on welder machine??

How do I make the counter show more digits? I have an input frequency of 69.3hz but the counter just flicks between 69 - 70hz. if I change the parameter FreqCount.begin(1000); to FreqCount.begin(10000); the counter shows 693.00hz so the full frequency but the point is in the wrong place. I am very new to the arduino so just learning any help please?

What’s I have been looking for. 💡 Converting stepper pulse signal from a CNC into a value to map to a pwm output gear motor control. I believe it will work for my application. Thanks brother💕 you are awesome

Could you use an op amp buffer and then comparator cct.....and then use it to measure low HF say ham HF ?

Basl in the glory of LadyAda, LOL! Nice little project. Peace.

How frequently does this measures frequency?

can u help me to change period to +Duty to measure duty cycle of a pwm signal

Nice project! It was good if the signal type (sinusoidal, square, triangle) was also displayed ...

can this little setup measure any frequency? are there restrictions based on the amplitude or anything?

I only had to make minimal changes for this to work on a Teensy 3.0, which is suppose to be able to measure up to 65MHz. The PJCR website has a page that tells you which pin to use and which won't work with analogWrite() while using this library. It doesn't list the Nano, but a Nano is just a small Uno without a voltage regulator. My display seems to have an error, in that it has a jumper for 0x78, but only works when the software is set to 0x3C. I have no idea why. I have seen comments from others having this same problem. www.pjrc.com/teensy/td_libs_FreqCount.html

Your awesome & thanks for expanding all our curiosities! At the moment I am trying to get the movement and angle looking at the end of a 1/2" shaft. The end of the shaft is splined with 34 very small teeth and behind that the nut holding everything bond in place. I can mount an enclosure as close as I want to the shaft but has to be completely enclosed.The shaft stays within a 0 and 50 degree range and moves very slow...very slow. Needs to be within 1 degree accuracy. Not so much a frequency project....or is it? Any suggestions?

Thanks for sharing your efforts. Q: can this work with a sine wave as well? I'm looking at setting up a simple ATMEGA328P (Nano) to monitor supporting DS1307 RTC and an SD (SPI) card module to tell if a 45VAC signal at 1350Hz changes by more than +/- 2Hz.

How could I convert that frequency to a 4-20 mA output and what hardware would be needed? Thanks.

What is the maximum frequently that the Arduino can read ?

I added to the circuit a 78hc4017 ci to read frequencies up to 60 MHz. how to add an offset line of 9,700mhz for use in cb radio

very good

Can this be run with a microphone input (digital or Analog) for the Frequency Capture source and what would the code changes be to make that work?

I have a tiny little LCD and I'm thinking of throwing a pro mini, 9v battery, and some leads in a 3d printed case for it. I'm planning on using it to check the ignition coils in some old cars so I'll need a voltage divider too(not on the hv side, on the pin that gets pulsed on/off)

Want to use this for reading high freq lighting controls via bpl in commercial construction. Would be much cheaper than the current standard which uses a DC signal on 18/2 to EVERY single luminary.

Great ! Simply clever, thank you, subscribed 👍🏻

what should be the minimum voltage of the signal whose frequency is to measure. I want to read Microvolt signal frequency, is it possible with arduino?

I was inspired into action finding this nice simple introduction to Arduino. Got this up and running, but I am out of my comfort zone with programming. How can I modify the software to display kHz with 100Hz resolution using only 4 digits? The frequency range of interest is 10kHz to 120kHz. And leading zero suppression would be really nice!!

Add some 3v Zener diodes back to back to protect your Arduino on the input.. Limiting the input to 3.0V ? eaa?

BUG: if the count is 0 , there is infmS displayed . I bypassed with if else so that i get a 0 if count is 0

Nice one.

can you build it to transmit would be great in the car for garage door and ham radio

hello thanks for video, very educative, is it possible to find a round trip time of a signal using arduino?

I'm a little bit confuse...For a short time (at min. 9 in this video), frequency is 80Khz and period shows 0.01mS. Hmmm. I still wanna keep the smoke inside the components... :)

Where did u get the frequency 10 khz?

what is the maximum frequency this project can read ? really nice.

I have build a function generator and this frequency counter It's exactly what I need. Unfortunately I have 128/32 OLED display. Can I use double slash before display.println(""); in order to fit all lines in 128/32 ?

Great video! Be careful with this metal ruler near the pins :P

Did you see how far you could push it frequency wise? It would be nice to try that on an 32-bit micro too. Thanks

Can you make sinewave a frequency counter

can i test ac voltage frequency with this ??????????

I do not see any information on how to set which pin to use for frequency input, is it locked to pin 5 only? Also I assume it only accepts digital input and not analog signals?

How about for sine/audio?

Excellent Video ! - Just what I need to progress my battery powered tachometer project (to be used to measure motor rpm in an RC boat) - Thanks ! Now if anybody can recommend a suitable optical sensor . . . .

Could this be used to generate an error signal which, when fed into a vco, could act as a frequency stability control for an oscillator?

can we read 50Hz sinewave signal with same library

Hi!! Good! what the maximun frequency read? thx!

I would like to set up this to read out in morse code. Can you show how?

What Can I do in this project to measure up to 10 MHz?

What is the max frequency it reads? Just curious! Wondered if it could be adapted to measure RF frequency to tune transmitters?

I am working on a project to turn frequency from striking a tennis racket into tension. We are using an Arduino microphone and thought this video was useful. How could you connect an Arduino speaker to this set up to display audio frequency?

This is absolutely fantastic stuff! It would be very helpful for me, if you could turn this frequency counter into a analog sound to MIDI converter to translate frequencies produced by guitar strings into a midi signal . I really would like to build such a thing, since I recently got cought by various synthizyser sounds and the equipment we find on the market, I just don't like and it is expensive as well. Furthermore it would be great, if this device is pretty small, so it can be hidden in an electrical gitars body with good looking nobs, if needed. Obviously we would need some coils with a magnet under the six strings, to get some voltage for metering. What do you say as an expert? Certainly I'd like to give you a hand if necessary. Regards Albert

Y *Yes!* Ia need this to realign my MJF-1278 modem from 1988/89.

What is the minimum frequency that it measures?

can i divide 1000MHz to 80MHz by using this way?

Fantástico!

Its a kool video but what can you do with a frequency counter?

Any way to make the frequency audible by chance?

For a device which is clocked to 16MHZ to measure a frequency of 1KHZ is very little and can catch this frequecy even using your own ear.

Do you have any idea, how to measure two different frequencys and show them on the display ?! I have to compare two freq's and write the realtions on the screen.... Please help !

hi there, may you post the code again? the link is broken.

Sir good project. But you have not mentioned the frequency range.

Arduino able to read how much maximum frequency.

How we can measure frequencies from 3 Mhz until 50 Mhz?

That Paul guy is the founder of the teensy. Go check them out!

Is it possible to measure the frequency wireless? By picking up radio waves

Hi. Could anybody please post a build of Arduino decibel meter for an Airgun with shown Max last reading. Small size would be preferable, possibly Arduino Nano and Oled screen. Most Android Phone Apps don't work correctly as the phone kills the Microphone sensitivity automatically and sampling isn't fast enough. Thanks in advance. Good Video BTW.

Can you at maths functions to this?

How low a frequency can it read?

Hmmm, how about an RPM Counter?

error in board arduino, why? error compilling for board arduino ..............(anything) can you help me?

Share for Coding frekuensi Counter Aurdiono master 🙏

can i use other pin except d5 ?

Can I actually use this for 1~1000Hz?

Hello! I see the input pin is D5. Where did you select this? I have a arduino uno, and I want to measure frequency. Thanks!

could that be adapted to a RPM meter?