first of all: I was searching a platform for Energy Monitoring for a long time. And with the open source IoTaWatt Project I found exactly what I was searching for. THANK YOU for that great job you did !!
But to meet my requirements on the mechanical design (available space for the PCB), I have to design my own PCB, based on the schematic and Layout I can found on GitHub.
I’m familiar with PCB-Develpoment but Software development is not my favorite. So I want to use the Firmware unchanged. I have compiled the Firmware from GitHub already with VScode & PIO.
1st question: Can I use the V5.0 hardware-design as basis for my own design and use the actual Firmware without changes? Seems there are no big differences to v4.8. I think you added the jacks on ADC6 + 7 to use the Inputs to measure alternativ the voltage of 2 additional phases in a 3-phase system?!
Is there some kind of Releasenotes for the Hardware and which Firmware is compatible to which Hardware version?
2nd question: On the schematic the Crystal ist labled with 32KHz. Am I right assuming it is a 32.768KHz ?!
I’ve moved this to the thread to the “homebrew” category.
Documentation is here, beyond that, what is in Github and can be gleaned by searching this forum. There are some release notes in Github and in the common.cpp source file.
That’s about it. The firmware runs as is on all versions of the hardware, but starting with the V5 hardware, the EEPROM is initialized in manufacturing to tell the firmware it’s V5 and to define the characteristics of some of the components like burden resistors and voltage reference shunt. There is a commented stub in the setup.cpp module that can be activated to do that to a virgin ESP8266.
It has a ESP8266 programmed board ( Platform IO ) that works on the original PCB and the original PCB has the ESP32 module marked 12S. Both work 100% on original PCB.
Note: You have to program SD card separately first.
I have put 3 x 9VAC transformers on PCB and calibrated them to correct AC voltage on web page.
I have tried to shorten and lengthen the CT wire length.
I used 0.1% 20 ohm Bleden resistors on my PCB. I did check with same multi meter they are the same value.
The 9VAC transformer 1K and 12k are only 1% not 0.1%
Do you Know where the PF calculation software file is done?
IoTaWatt uses an ESP8266-12S, so I think you are somewhat confused. ESP32 will not work at all in the ESP8266 circuits.
IoTaWatt collects three fundamental metrics related to a CT input:
Voltage
Watts
VA
All other metrics are calculated from those values. Power Factor is simply:
Watts / VA
You can extract Watts and VA from both and see how those metrics compare.
One caveat: Although the script system will calculate PF for inputs that are added or subtracted, the result is essentially useless as it does not accurately reflect the net reactive power that results from the interaction of those loads with each other. The only way to do that is to combine the circuits into one input by passing their wires through a single CT.
The ESP8266-12S shows large 12S on module wile the other modules show ESP8266MOD are they the same?
If I use 30 pin module on original PCB the power factor correction value is a mathematical calculation of original PCB =1 with a light bulb.
If i use the same 30 pin module the power factor correction value is a mathematical calculation answer is different because the PCB is slightly different 0.95
To fix the problem i would have to change the mathematical calculation to suit my new PCB?