Develop own Hardware - detail question


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 ?!

Thanks in advance and best regards,

Hello Jan,

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.


Good Luck.


Thank you for this ample answer. I hope I will get it running fighting actually with Fusion 360 as follow-up for eagle…

Best regards & keep on going with this great project!