Ethernet connection using travel router

Case Studies
1

Count me among the people who were annoyed that the iotawatt didn’t support ethernet. But I’m annoyed no longer! I found a setup that I’d recommend.

I have two iotawatts mounted inside our electrical panel monitoring 24 circuits. The panel is on a finished interior wall so I didn’t want to add any more boxes or doors – it’s ugly enough as it is!

I tried to use wifi but that was impossible… when the panel door closes, wifi goes to zero. It’s pretty wild to watch… if the door is just slightly cracked then everything works perfectly. Snap it shut that last tiny bit and the signal is gone.

So I stuffed an inexpensive travel router into the panel with them (I used TP-Link AC750 Wireless Portable Nano Travel Router TL-WR902AC but there are lots). It bridges the iotawatts onto the ethernet and even has a USB passthrough to power them (via a cheap USB Y cable… in theory this could cause power issues but it’s just so tidy and I don’t see any noise/reliability issues so far)

The router was cheap ($35, less than 2X the cost of a PoE injector), compact, and rock solid. Three wifi devices mounted inside metal can barely bigger than they are has got to be a ridiculous RF environment but they don’t seem to mind.

So, would I prefer ethernet? If a single iotawatt could monitor 30 circuits and support PoE, then sure, that does sounds better. But if 30 circuits needs two iotwatts and a 4 port PoE switch then no, I’d prefer my current setup. It’s more flexible, more off-the-shelf, and works better than it seems like it shoud.

Now I just wish the iotawatt had a temp sensor so I could see if the lack of airflow is an issue…

2

Nice solution. Just a word of caution on the split USB power. If you are also splitting the AC reference, and you have not yet seen smoke coming from one or both units, you probably have the polarity correct. However, this configuration puts both units on a common ground and can cause the two to basically fight over over any minute differences in bias voltage. I don’t recommend you leave it this way long term. Better to add an independent USB power to one of the units.

I can think of a couple of ways to add temp, but if you are a tinkerer, here’s how one user did it: