I'm trying to create an energy monitoring plug which will tell you the energy used by the device plugged in; the same as a Kill-a-watt.
My plan is to use an off-the-shelf digital timer enclosure, add a small AC-DC converter and an ESP8266 for wifi, all controlled by an Arduino.
I've taken apart one of these timers, and because they're designed to switch the power on and off to the device plugged into them, they have a relay in series with the live pin. The neutral and earth pins are just solid pass-through pins. The image below is looking from the socket side showing the solid E and N pins with the right live pin in two sections with the red wire:
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I could use a resistive divider and isolated ADC to measure the voltage, and a current monitoring IC (hall effect or similar), but I found that the big IC manufacturers all make smart metering IC's to do all of the power calculations for you.
I found the MAX78700 and MAX78615+LMU combination which requires a shunt resistor, but provides completely isolated measurements. The MAX78700 actually reads the current and voltage, receiving power and transferring data with the MAX78615 via a transformer. Exactly what I need 
Now, they have a development board called the Sonoma which shows how to use both of these products and is actually exactly what I need and the specifications match what I need (max 8A, 230Vac).
However their wiring hookup guide requires the shunt to go in series with the neutral wire, which isn't possible in my enclosure.
Can I use their same schematic (shows only the MAX78700) but change the live and neutral wires around? Would I have to change anything in the schematic? Is there anything more dangerous with measuring the live side rather than neutral?
