Hi and thanks for having shared your work. Where can I find more information about how to calibrate these 3 parameters: _VCAL, _PHASECAL and _ICAL ?
Thanks in advance
particullary can someone give me more info on how to accomplish the
Step Four - Calibration --> Step two – calibrating voltage and current
on this page?
what I have done is this:
I have put a multimeter on the 230V socket, compared it with what I obtained and chenged VCAL to obtain the same value. In my case VCAL=242
I compared emon arduino circuit results with an amperometric clamp. I made many test with different instruments but only changing ICAL i did not obtain good values. I added another constant term "q" so that in the equation we have y=mx+q or i=ICAL*(sqrt(sumI / NUMBER_OF_SAMPLES))+q. I don't think it is necessary to calculate I_RATIO because this will be const, it is not wrong but it spend microcontroller cycles. We can put directly ICAL in the line equation (we decide ical value so it is easy to change it). Do you agree and if not why? In this way I obtained accurated valus (my equation isIrms = 0.2781* (sqrt(sumI / NUMBER_OF_SAMPLES))-0.0714)
I am lost and I have no idea about how to calibrate it. Any suggestion?
We have recently improved the emonTx calibration instructions: http://openenergymonitor.org/emon/modules/emontx/firmware/calibration%20
Open-source tools for energy monitoring and analysis. This project uses the GNU General Public Licence