Just looking for a wee bit of advice.
I wish to build an energy monitor, with WiFi and MQTT and to do so I'm going to use the LinkIt Smart 7688 DUO, mainly because I have some lying around, but also because it has an ATMEGA32U4 slave processor on it that can do real-time tasks.
So I thought I'd use Efergy Energy Monitor clamps - again because I happen to have them lying around.
I will DC Bias the signal from the clamp, so that the full wave falls within the ADC range.
However, I have a question - what is the best (Not necessarily easiest!) way to calculate the RMS of the incoming signal, given that it will be DC biased?
Should I just subtract the mid-point from all the samples, and thereby convert all the ADC readings to signed? And then do the RMS calculations from there? Would that be the correct approach?