Sine wave measurement, need some suggestion.

leoren_tm · ‎2010-09-16

Posted on September 16, 2010 at 11:09

anickol · ‎2011-05-17

Posted on May 17, 2011 at 15:10

As usually, it depends.

First of all, what exactly do you need - an instant peak value at every peak or an average peak value in some time period ? You might need an instant value if you have a transient process, like oscillation decay in a LC circuit. In a stable circuit you'd more likely want to measure an avearage peak value.

Another question is: do you want to know your value as soon as the peak has been passed, or you need just to know amplitude, but not the time ?

Anyway, to measure parameters of the sine wave (there are only 3) you do not need to do it instantly. You can do measurements at any rate and then calculate the values you need.

leoren_tm · ‎2011-05-17

Posted on May 17, 2011 at 15:10

Hi all.

Can anyone help get to set-up ADC to measure at a rate of 1khz? Im thinking of using TIMER1, on a slow channel group, or any much simple way.

thank you

leoren_tm · ‎2011-05-17

Posted on May 17, 2011 at 15:10

Hi Alex.

In my application, input sine is wave is continues and in that ill just need to measure peaks when my circuit is stable, or simply an average peak at a certain time when circuit is stable. The main problem is, how to measure the peak base on DMA-DAC configuration. in that, when my DAC is at peak value, ill trigger the ADC to measure it.

and because its fixed 2khz sine wave, i just need to measure the amplitude. I did try measuring at 20khz, but then this causes noise on ADC interrupt, and maybe consume more power, as compare to triggering ADC only at peaks.

Thanks

leo