Problem/question about frequency period counter

turbosupra

Hi,

I am using the jm_freqin object, specifically the period method that counts cycles between a pin seeing a high and the next time it sees another high. My problem is that I need to sample faster than the method return value is being updated, so I get duplicate values. My dilemma is that the value update rate changes independently and randomly as far as the propeller is concerned, so a fixed sampling rate will not work and sometimes the previous and current values being identical are valid method return values as well.

I can't come up with a way to code around this so that I know I'm reading an updated value, and not a duplicate because of the sampling rate. Does anyone have any ideas?

Thanks for reading.

Phil Pilgrim (PhiPi)

Here's what I would do. Modify Jon's period routine like so:

pub period

'' Returns period of input waveform

  result := fcCycles
  fcCycles~ 

If, when you call it, it returns zero, you will know that it hasn't updated since the previous call.

-Phil

turbosupra

You are the man!

Thank you so much Phil, a simple solution that works great.

Phil Pilgrim (PhiPi) wrote: »

Here's what I would do. Modify Jon's period routine like so:

pub period

'' Returns period of input waveform

  result := fcCycles
  fcCycles~ 

If, when you call it, it returns zero, you will know that it hasn't updated since the previous call.

-Phil