Energy meter schematic query

[Vindhyachal.takniki]

I have made a schematic using ADE7753. Attached is the ckt.
ADE7753 is powered from 5V & micocontroller is 3.3V one.

1. In the ckt I found that neutral of system has to be shorted with microocntoller ground & ADE7753 ground. Is it ok? Is this how it is done?

2. Is there any way I get to know that line & neutral are interchanged in the system. Because I have seen generally in house meters there is led indication showing if line is connected to neutral & neutral is connected to line.

3. I have to connect it to 3.3V micocontroller. In datasheet of ADE7753 VIH is 2.4V or I think all ouput lines on SPI can be connected to MCU directly while for MISO I connected a 1K resistor in between. Is it ok?

4. Max adc inputs for ADE7753 are 0.5V max. So calaculations for voltage are:
R4: 1M  (will connect two 500k in series)
R5:1K
At 275Vacrms, 50Hz, Vp= 389Vp
So voltage at input = (R5/(R4+R5) * Vp = 0.39
So I think its ok

5. Max cuurrent to be measured = 50Aacrms
So Ip= 70.71V
With CT of 1800:1; I = Ip/1800 = 0.039V
With burden resistor of 10ohm V = 0.392V

6. Are above calaculations ok?
7. Is ckt ok?
8. Is there any example code. I found some of net: https://searchcode.com/codesearch/view/17414705/
Will took reference from this code & see if it works.

[LukeW]

A few general things to consider:

If you're not certain about what you're doing it may be safer to use a fully galvanically isolated system, using a current transformer and a potential transformer.
That way it does not need to be referenced to the line or neutral at all, and you can connect your PC, microcontroller tools, scope etc to it while the system is online safely, without worrying about it.

If you want a galvanically isolated voltage sensor, can you kill two birds with one stone and use the power supply transformer for an acceptable voltage waveform acquisition?

If you're able to accept a system without galvanic islolation then the current transformer is a pointless waste of money - use a simple shunt resistor instead.

[Vindhyachal.takniki]

1. I need to do some processing & segment display to be added. That why MCU is interfaced.
2. Data is displayed on LCD for outputting data.

Link for my ckt query on AD devices forum: https://ez.analog.com/thread/88685
Going to use last ckt I posted in it.