Nice project. Even though some items are in a language I do not understand, the sketch provided me with a better understanding of the MySensors work. Thank you for making the connection of what I know and what I was having trouble understanding.
We are of like minds, Don't like the cloud based controls (that's another discussion).
In my case I have a Bryant/Connex system, heat pump, variable speed fan and 4 zones. There's a lot going on: the 4 zones creates 16 profiles. The fan speed for a profile will depend on the indoor and outdoor temperature. The thermal fluid pump also has to be controlled. A profile will have an optimal air pressure, so there's a sensor there.
The controller works just fine not being connected to the cloud. But I want to set the parameters remotely, Bryant/Connex can do this. I also wnat the status of the various actuators and sensors to show up in Home Assistant.
The signals sent over the RS422 are proprietary. My plan was to reverse-engineer the signals. After doing this I'll have to experiment to get the right mix of air pressue, fan speed and thermal fluid flow for each profile.
I'd like to do the same for my AO Smith heat pump water heater.
I'd like to follow your progress.
OSD
@OldSurferDude yes, you are correct. this sensor is capable of 50A continuous, which safely I would make it working at 40A max., but for such an important load as in your case I would go for a beefier one, like the ACS75x, 77x, but at this point I would also change the node's form factor for space and insulation reasons.
On my application on the RV I have a max. curr. of 13A running on a AWG14-16 cable (European rules for RVs), so I did not ask myself too many questions beside, of course, safety.
About the signal, it will be a sinusoidal signal swinging around Vcc/2.
Vcc can be easily measured internally on the ATmega328. On all my DC sensors I measure Vcc at every loop, just before measuring the ADCs.
Honestly, when the space is not an issue like in my RV, I would rather use a ring core current transformer, and I would get rid of noise, response time, power dissipation, but over all no need to cut any cable.
Long story short, it has been a nice experiment and I used it for 6 months, and then I switched back to my RF-NANO based RS485-Modbus - Mysensors bridge connected to an off-the shelf power analyzer.
Just for fun I attach a pic of my 12Vdc sensors installed on my RV. Forgive me for the spaghetti wiring on the right side, but this is an area that needs improvement.
The output of the display could also be sent over serial, but the whole idea is you can walk around with the doctor and improve your results as you go.