So I went through this from the learn section and did some changes. I swapped the uno for the esp32. Since the ESP32 has 3.3v power I used an 18k(1 watt) burden resistor. The other 2 resistors are 22k ohms. Everything else is the same.
Q1. Are the components right to go ahead and test with an extension board.
Q2. To calculate watts can I multiply the IRMS reading with 240v(Home voltage india.) ?
We don’t normally recommend the ESP32 for energy monitoring, because there are questions regarding the accuracy of the ADC. Some claim that these problems have been rectified.
I don’t know the input parameters of the ADC without looking them up, you design the input circuitry so that the peak-peak voltage swing at the maximum current you want to measure covers just less than the available voltage range of the ADC.
No, multiplying the rms current by your nominal or a “best guess” voltage will only give you a nominal
or best guess Apparent Power in VA. You can only have Real Power (aka Active Power) if you measure the voltage and multiply each pair of voltage and current samples and then average the result, as we do with emonLib/emonLibCM and the Atmel ATMega 328P, or the Arduino range. You must have at least two ADC inputs.
I see. So would it work with this CT which has a voltage output or it would still lead to knowing apparent power because this time there is only voltage? Also we can have a different ADC input pins that transmit the messages to esp32 who further transmits it to the cloud. Is this a viable solution in your opinion or is there a better one out there.
A voltage-output c.t. is only a c.t. with an inbuilt burden. It behaves no differently to a ‘proper’ c.t with its burden.
In my opinion (and it is only an opinion), the simplest and easiest non-professional solution for energy monitoring remains the Arduino Uno or its near equivalent.
I haven’t tried to use an ESP32 for energy monitoring, it seems those that have used Espressif devices usually add a dedicated ADC and use the ESP purely for number-crunching and networking.