But you’re getting readings back more frequent than that? Your call, but if it were me I’d be wanting to get to the bottom of that. You might end up with all sorts of strange beat effects if you’re not sampling when you think you are or picking up the same reading twice.
Interesting. I wonder if you could have done away with the mid-rail and just used 0V as a mid-rail. That’s how most energy ICs work too, the V and I signals swing either side of GND.
Yes, I think the STM32F0 development board I got is about US$11, complete with Arduino headers. Alas, no wifi though so that’s a big plus there for your ESP8266. It’s all starting to make the old traditional Arduino stuff look as historic and folkloric as a black-and-white TV though.
Yes, when it comes to calculating the maximum (or minimum sub-zero) voltage you’re going to subject your ADC input pin to, it’s the peak that matters. In the case of I, your current signal might be a long way from a sinewave and very peaky so a simple root-2 multiplier is generally not enough. Robert has a rule-of-thumb multiplier he uses that takes into account some level of peakiness and component tolerances, but I can’t find it right now. You may be able to find it with a search.