You can read negative half wave simply biasing input at Vcc/2 .https://learn.openenergymonitor.org/electricity-monitoring/ctac/how-to-build-an-arduino-energy-monitor?redirected=true
If he really wants a "True RMS" meter he needs to account for the DC component.
I'm going to guess it might not meet your basic goal (I'm thinking this is an exercise in "can I do this"),but if not there are some RMS to DC converter IC's you could use.JR
Google knows a lot more than you:http://www.analog.com/media/en/technical-documentation/data-sheets/AD636.pdf
Not any shape. You are supposed to say that your waveforms will have a crest factor of more than 6. 8^)It is much funner with the arduino anyway. Next you are going to be asking for an integer square root algorithm!
That was 6(period)(space)(8 for smiley)The crest factor has all to do with accuracy, not protecting the hardware.You, of course have the same issue. You will need to sample at more than twice the highest harmonic you want to capture.