Power supply options for emonTx Arduino shield v2


I am just considering my options before purchasing and wanted to check something. I want to use MQTT over ethernet for all sensor reporting as I have CAT6 next to my distribution board and would prefer to eliminate any potential issues with RF.

So I am considering buying an Arduino Uno + ethernet shield, and then plugging the emonTX Arduino shield on top. I note that the emonTx v3 prebuilt version supports powering the node via the 9VAC supply. Is this the case for the v2 Arduino shield as well?

I will definitely be connecting a 9VAC supply (I have a 'Type 2' PV system) but I would like to use that to power everything rather than having to have a second DC supply just for the Arduino + ethernet shield.

I have a feeling I am out of luck but I just wanted to get confirmation. In that case are there any other suggestions for connecting an emonTx v3 using ethernet?

Many thanks,


Robert Wall's picture

Re: Power supply options for emonTx Arduino shield v2

No, the Shield picks up its power from the Arduino, I can't immediately think of a way of powering anything connected with Ethernet from the EmonTx V3 as there is very little spare current available when using the ac adapter to power it, and generally Ethernet requires rather more power than is available.

You could connect the V3 directly to a RPi (this way), but you still need a separate supply for the Pi.

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