Computation of TRMS value

Hi ppl,

I´m trying to find an optimized way to calculate the RMS value using the ATmega.

I´m am acquiring sinewaves with the ADC and i want to compute their RMS value after.

Is there any available library for this or does anyone have a good sugestion for starting?

Best regards

Can you post the code you have sofar?

  • what is the freq. of the signal?

  • what is the freq. of your samples?

Hello,

So far i haven´t yet started to code the feature.

I am still looking if there is code for that, i don´t want to invent the Wheel... :slight_smile:

But i can give more info about the signal:

  • Power network current
  • Frequency 50Hz
  • Still haven´t thought about frequency, but i think i´m going to do subsampling

Any sugestions?

reader about ADC is allways interesting

Hey Robillart,

And what about algorithms for the computation of this values any library or suggestion?

Robillart,

Almost right :wink:

And what about algorithms for the computation of this values any library or suggestion?

No, sorry, think you should ask in the General Electronics subsection

20 seconds google -> found this on wikipedia - Root mean square - Wikipedia -

For a sinus the formula is

RMS = amplitude/sqrt(2);
RMS = amplitude * 0.7071068;

The amplitude is the half of the [ maxValue-minValue ] dusring minimal one period.