For those who like designing circuits, I have a little project for you. I like designing too, but I know so little I'm not sure how to go about making a frequency counter. Devices with the capability I'm looking for are way out of my price range, and I'm hoping that building my own simple version will be much cheaper.

Here's what I want to accomplish:
I want to be able to, for example, measure the sound of a whistle and have a digital or analog display show the Hz, preferably to the hundredths of a hert with a measuring range of at least 20-18,000hz or 1-20,000max. I would like it to choose the loudest frequency it hears for measuring like how a tachometer for an RC airplane propeller measures the strongest pulses of light out of all the pulses it sees. I want to build it myself if there are no such devices readily available at a low cost. It can be analog or digital, a design I don't have to program, calibrating is OK if needed. Simplest and cheapest design with precision to 1hz, preferably to .01hz

What I would like from you are suggested parts and how they should be configured. If a special programmed processor is required I may consider compensating someone for making it.

I hope this is the right place to ask about such a project, where you may do most of the designing. Thanks

 

Here's what you need to do:
1) Pick up mobile phone
2) Download spectrum analyser app
3) Install spectrum analyser app
4) Enjoy your new spectrum analyser

 

My phone is too old, it still has a singular background with the orange X shaped guy. Thanks for the attempt at a very easy solution, I wish I had a smart phone.

 

Can I get an app to work on my computer? There has to be an app for that right

 

The second easiest way is to use a 16F628 pic and build a frequency counter based on this chip. There are many design based on this and you can just google "16F628 frequency counter" and you'll be able to find one.

The next easiest way is to build this old 1980 3-chip design from Radio Electronics 1980 Dec issue. It was based on the intersil ICM7216 chip with LED display...
The project pdf and the 7216 datasheet are attached fro your reference..

Allen

 

google did not help...?

 

You may check your local music stores or ebay. They have sound calibrated that do just that. Roughly 10 USD each, complete with battery, display and microphone.

 

Googling "frequency counter app windows" gives several hits for freeware.

 

Hello,

Have a look at Audacity, a audio program that can manipulate audio.
http://sourceforge.net/projects/audacity/
http://audacityteam.org/

Bertus

 

I'll look into those designs to build. I found the audio frequency counter app which is exactly what I want as it shows hz and can be tuned to filter out other sounds. I've been burning up data today trying to figure out how to run it on windows 7. Just so you know, the app I mentioned is an advanced version of what I want, the spectrum analyzers and instrument tuners are not really what I want. I'll post an update as I figure things out. Thanks for the help so far.

 

The 16F628 based counter looks like it could work, but many designs out there are for measuring crystals. I found a kit for one, but I hope it would be easy to make it work with a microphone input and turn it's 50mhz ability into precision as I don't need to measure above 20kHz. I wouldn't know where to start in terms of modifying it until I become familiar with how the chip works.