Hi,

Im bringing up our energy meter prototype based on ADE7880.

I connected only phase A, voltage and current are measured and scaled right by AVGAIN and AIGAIN. The frequency and ANGLE seems also correct.

AVRMS = 452 ( scaled 45,2V, I use a transformator to work with harmless power on my desc)

AIRMS = 142

With APGAIN = 0 I expected in AWATT something around 4000. (AVRMS x AIRMS / 16)

But I get no data from the power, powerfactor and energy registers.

AWATT, AVA are 0 or -1,

AWATTHR counts very seldom.

Any idea?

Is anythere any sourcecode of an example initialisation?

Thanks for hints in advance

Hi Borstel,

Do not try to scale AVRMS and AIRMS to give you real world voltage and current values because that causes a loss of precision in the measurement. If it is just one ADE7880 that you are testing, I suggest not modifying the gain, and reading the AVRMS/AIRMS registers that you compare to an accurate source or reference meter. Then using the register value and the accurate source value to find a V/LSB and I/LSB constant that can be used to convert the register value to a real world value.

In order to get stable RMS readings with no ripple, read the RMS register at least 50 times in one second and average that value. Then use this averaged value to find the V/LSB or I/LSB constant.

Then you can repeat this with the AWATT register to get a Watt/LSB constant to convert the register to a real world value. At this point the averaging is not required to get a stable AWATT value.

I would recommend taking a look at the Calibration Application Note:

http://www.analog.com/media/en/technical-documentation/application-notes/AN-1171.pdf

This has lots of useful information and please let me know if you have any more questions.

Regards,

Dlath