that's why we included the LEM 4-20mA current clam on the board
I don't understand what you mean. You mean there is a current clamp ON my board? I don't see one can you point it out for me?
that's why calibration is advised.
What calibration? Where is the documentation for this calibration? Your site appears only to include an english document for the v20 smart sensor borad not the one without a version number and the interface is not documented in the api browser. The relationship between the live current and the readValue() return value appears to be non-linear and I have no documentation to tell me what this relationship is and how to go about calibrating / calculating.
could you post to which current values correspond each of them and how did you carry out the test?
I discovered that the mote was missing the 3v button battery. After I put this in the results were more consistent though still non-linear. I have explained about the wiring and provided the code, here are the values for three tests with a 2kw fan which has 3 settings, cold, hot @ 1kw and hot @ 2kw.
Mains live: fan only (cannot be read by my free proprietary utility reader either) or off
readValue returns mostly aprox: 0.001
Mains live: Aprox 1KW (Aprox 4 Amps?)
readValue returns mostly about: 0.021
Mains live: Aprox 2KW (Aprox 8 Amps?)
readValue returns mostly aprox: 0.191
this is a low cost sensor that shows some nonlinearities and lack of accuracy
How inacurate? I did not realise that it would be especially inaccurate, if I had I probably would have spent the extra money to get the ones for specific ampage etc.
Regarding documentation - Can you tell me where I should have navigated on your site to find documentation to understand how to calibrate and interpret efergy readings? Or was this information simply not available through your site?