Battery powered sensor AC voltage drift

[dBC]

@mihai.aldea

There’s no reason to run the ATmega328 at 16MHz.

OK.

@mihai.aldea

I’m not sure that this would have an impact on the speed of the measurements though.

You can still run the ADC at 125kHz but the maths will take twice as long. See also About ATMEGA328P with 8Mhz internal oscillator crystal. Standalone

@mihai.aldea

I wonder though if a large capacitor and a diode would smooth the AC curve up to the point that only 10 readings or so would provide a steady reading

What is it you’re trying to measure? Real power? Do you want a steady reading, or an accurate reading? If you want an accurate measurement of Real power, you want those AC signals to be as undistorted from the original as possible.