• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Frequency counter

Not open for further replies.


New Member
I am currently doing a project that involves making an infrared based heart rate meter. If anybody has done same thing then I would appreciate any info.

Specifically , I wanted to know abt suppose I have digital pulses(heart beats), then how do I count the heart rate. I know how to make a conventional frequency counter in which counting time is 1 sec, but here the counting time is 1 min, so if I do by that method then the problem is of generation of a pulse of less than 1 Hz freq.

Nigel Goodwin

Super Moderator
Most Helpful Member
There are essentially two ways of gating a frequency counter, either gating the incoming frequency for a fixed time (measuring the frequency), or using the incoming pulses to gate a fixed oscillator (measuring the pulse width).

You normally use the first for high frequencies, and the second for low frequencies - but for the second you have to convert it to give the required frequency or B.P.M. for heart rate.

It's easier to do it with a micro-controller, you might have a look at this PIC based version? http://www.web-ee.com/Schematics/HeMon/HeMon.htm.


you need a hi freq counter with stop start feature and count time interval between heart beats
Not open for further replies.

EE World Online Articles