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Hi,

This is my first post. It is great being part of this exciting forum. I look forward to being part of this community of like minded people.

I am doing a project on Smart Meters.

I have built the hardware slightly different to the one recommended on this site.

The current sensor has a max Primary current Ip of 50A.
The conversion ratio is 1:2000 , so the secondary Current Is = 0.025A.

I've connected this to a 200ohm burdern reister so that the max voltage it will send to the Arduino is 5V.

After reading in the value I convert it back to the actual current with this line of code.

          Iin=((Iin/204.8)/200)*2000;

where
204.8 = 1024/5V (1024 is the Arduino max digital value) and 5V is the max value for 5V input.
200 is the value of the Burdern resister i.e: 200ohms
2000 is the conversion ration on the supplier spec sheet.

The Maximum current values are close to what I get on the multimeter. About 0.3A for a 70W light.

However, I need to convert it to an Irms.

I would like to use the code supplied by openenergymonitor to do this but I am not sure how to go about doing so.

How do I adjust the callibration  parameter(111.1) as well as the 1480? (what is this) so that it will work for my setup.

  emon1.current(1, 111.1);             // Current: input pin, calibration.

  double Irms = emon1.calcIrms(1480);  // Calculate Irms only

Any help is appreciated.

Kind Regards