How to detect wave crest accurately?

"X.Y."

One cannot detect maxima in a unpredictably varying value UNTIL after it has passed.

Any uncertainly ( ie noise) in the readings ( samples) will only add to the delay in identifying the actual instant the rate of change reversed sign and determining exact peak value achieved.

Identifying the exact moment of a maxima only comes after all the relevant samples have been smoothed and re examined.

...... Phil

Maintain a running maximum in software, that you reset each cycle.

Good Luck! Rich

You can't really do that, a crest on a waveform is only relevant over a given time period. Why do you want to do it? What sort of input waveform are you measuring? Is it known and predicable, or unknown?

For say a smoothly varying waveform like a sine wave you could use a (small) running average and then detect the change in direction of the average (and reset your average), but that only gives you an indication several samples after the actual maximum.

What are you really trying to do?

Dave.

figure out exactly what you mean by a wave crest as it is represented by the samples you are taking, and then write software that detects that.

Bye. Jasen

Polynomial curve fit, maybe.

John