Go Down

Topic: High frequency measurement using Arduino Due (Read 2 times) previous topic - next topic

retrolefty


The problem is using the Analogread(), I can only read the values from ADC up to 10,000 samples/sec which is the maximum of 10kHz for the input signal. I also found an example of using ADC in free mode, which I was able to measure the frequencies up to ~190kHz. Please let me know if you know of any other way to read the values from ADC.


Measuring a signal's frequency via it's amplitude values via an ADC is simply the wrong method. I suspect you will not get anything to work worth using. To measure frequency one counts signal zero crossings for a fixed 'sample time', then store the result and reset the count for the next sample window.

Lefty

shahabai

Quote
To measure frequency one counts signal zero crossings for a fixed 'sample time', then store the result and reset the count for the next sample window.


Could you please explain more what do you mean by counting the signal zero crossing? I am newbie anf I appreciate it if you could explain it more or even give me a sample code for doing so.


retrolefty


Quote
To measure frequency one counts signal zero crossings for a fixed 'sample time', then store the result and reset the count for the next sample window.


Could you please explain more what do you mean by counting the signal zero crossing? I am newbie anf I appreciate it if you could explain it more or even give me a sample code for doing so.




http://interface.khm.de/index.php/lab/experiments/arduino-frequency-counter-library/

Lefty

shahabai

Does the library work on ARM processors? It looks to me that it was written for AVR processors.

retrolefty


Does the library work on ARM processors? It looks to me that it was written for AVR processors.


Yes it was, just look at the dates, the Due came out late last year. I'm sure it could be modified if needed. I posted to show you the method used so that you can come to the conclusion that trying to use ADC to determine frequency of a signal is just not the way to go.

Lefty

Go Up