simonstar

I need to analyze the frequency of a square wave coming in from the adc input. The freq of the wave varies between 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and measures time between them. This works but only up to 10000Hz.

Is there a better way? Or a msp command or external that does it?

Hello
I need to analyze the frequency of a square wave coming in from the adc input. The freq of the wave varies between 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and measures time between them. This works but only up to 10000Hz.
Is there a better way? Or a msp command or external that does it?
Thanks
Simon


analyzing-frequency-of-wave

does way more (maybe a bit too much for what you need) , but you'll be 

> I need to analyze the frequency of a square wave coming in from the adc input. The freq of the wave varies between 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and measures time between them. This works but only up to 10000Hz.

> Is there a better way? Or a msp command or external that does it?

check out the analyzer~ object ( http://www.maxobjects.com/ )

does way more (maybe a bit too much for what you need) , but you'll be 
able to get the freq from it.

simon wrote:
> Hello
> I need to analyze the frequency of a square wave coming in from the adc input. The freq of the wave varies between 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and measures time between them. This works but only up to 10000Hz.
> Is there a better way? Or a msp command or external that does it?
> Thanks
> Simon
>
>


To be more specific: I need to sync the playback speed of a wave file to the incoming signal. The signal is generated by a movie picture camera running at variable speed. So the sync has to be very accurate.

Still another option would be to download FTM, and use grb.yin:

http://recherche.ircam.fr/equipes/temps-reel/ftm/index.html

> I need to analyze the frequency of a square wave coming in from the adc

> input. The freq of the wave varies between 

> 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and

> Hello
> I need to analyze the frequency of a square wave coming in from the adc
> input. The freq of the wave varies between 
> 50Hz and 20000Hz. I have made a patch that counts the peaks of the wave and
> measures time between them. This 
> works but only up to 10000Hz.
> Is there a better way? Or a msp command or external that does it?
> Thanks
> Simon
>


> Hello I need to analyze the frequency of a square wave coming in from

> the adc input. The freq of the wave varies between 50Hz and 20000Hz.

> I have made a patch that counts the peaks of the wave and measures

> time between them. This works but only up to 10000Hz. Is there a

> better way? Or a msp command or external that does it? Thanks Simon

analyzer~ and all the other fiddle~ based externals are pretty expensive 

for what you want to do. In theory it should be no problem with your 

described method to achieve it for higher than 10 kHz. There might be a 

bug in your program. You even would not need to look for peaks, if you 

clip your signal, you only need to measure the distance between jumps 

from 0. to 1. for example. You can multiply the input with a high value 

simon wrote:
> Hello I need to analyze the frequency of a square wave coming in from
> the adc input. The freq of the wave varies between 50Hz and 20000Hz.
> I have made a patch that counts the peaks of the wave and measures
> time between them. This works but only up to 10000Hz. Is there a
> better way? Or a msp command or external that does it? Thanks Simon 

analyzer~ and all the other fiddle~ based externals are pretty expensive 
for what you want to do. In theory it should be no problem with your 
described method to achieve it for higher than 10 kHz. There might be a 
bug in your program. You even would not need to look for peaks, if you 
clip your signal, you only need to measure the distance between jumps 
from 0. to 1. for example. You can multiply the input with a high value 
and then send it through a [clip~ 0. 1.]

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Analyzing frequency of wave?