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.
Quick Range Check on the WIO-E5-LE. The LE version uses only the low power PA, +14dBm max. Using the default settings except for 915MHz
#define MY_SX126x_FREQUENCY (SX126x_915MHZ)
#define MY_SX126x_LORA_SF LORA_SF7
#define MY_SX126x_LORA_BW LORA_BW_125
#define MY_SX126x_LORA_CR LORA_CR_4_5
I get about 190 meter range, just walking around the neighborhood, line of site except for some trees and power lines.
No tuning on the antenna. Just using a 77.9mm wire.
Not as dramatic as some have achieved with LoRa radio's, but plenty good enough for my house and yard : )
@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.
