I have this question. If I have 3,4 sensors in one setup and one instance of emoncms like having different sensors at different parts of the house, do I have to buy each sensor AC adapter to measure the voltage of the grid? We need just one AC adapter in one emonTX3 let say and then the voltage could be fed to all the sensors in emoncms. I did not find a way t do this…
What are you trying to measure? Power, Temp, Humidity?
If power of individual devices is what you are after, you can use something like a SonoffPOW. These are reasonably accurate and can be setup to pass the power readings into Emoncms via node-red for instance.
If the circuits come back to one distribution box you could just use a CT on each circuit if there is enough cable.
I flash the SonoffPOW with Tasmota first, then it is simple to get it to publish via MQTT. I then pick up that data with node-red, parse it, then publish it for Emoncms to pick up via MQTT (or using the emoncms node).
I usually buy a short extension lead and wire the SonoffPOW into the extension lead.