Custom build outlet plug for device detection

Hello guys, I was as many of you waiting for my device detection, I have been using my sense monitor for around 3 weeks now, and I have minisplits and some maker stuff, 3d printers, resin printers etc. I realized that some devices use the same signature and sense just assigns the wattage to the wrong device or when the minisplits are on, as they are inverter technology, just doesnt seem to detect correctly the device, any way, in my effort to isolate everything correctly, I created a dupe for an outlet plug, and since it is a custom build, I added a little buzzer when the wattage is getting high and also homekit, alexa and (on the works) google home integration, I am attaching some pictures to share the build with u :slight_smile: if anyone is interested, I can provide some at a low cost :wink:

the main chip is a esp8266, the case is made from resin, and the blades that go in the wall, are made out of pcb for now, cause i havent found the standard silver ones.


Could you make a 240 volt version of that easily?

Very cool, thank you for sharing - you’re going to popular in the Community!

I’m painfully unaware of the material/spec requirements for outlets and defer to the more knowledgable folks here on whether or not this is a potential fire hazard :slight_smile: .

You didn’t explain how this aids with device detection or am I missing something?

Also many states within the USA require proper ground (none seen). Be careful offering to sell something that’s not UL listed, not under corporate veil and not without proper advice from a lawyer, as you might be liable for their house if it burns down, or catch a case.

That being said, ESP devices are a blast to play with.

I just looked back thru the thread to see what this is about, but nothing I could find. Has someone figured out how to monitor 240v devices?

Using zwave and HA you can easily do it.

Hello @DevOpsTodd you have a point, i havent submitted to ul certification, as described above, it is just a dupe for the ones Sense has already a working integration specifically the tp link kasa. As I see your username, u understand a little bit of bolts and nuts, so answering your question, the esp exposes an udp port 9999, which Sense keeps pulling data from, and the response that i send back is the watts being used, and thats how u help sense start isolating, primarly i used it for devices with similar signatures, such as tvs, printers, my 3d printer. According to my infrarred analysis the temperature inside has been constant and still under the range of starting to get concern about.

Any way, your comment is a starting point for me to dig in :slight_smile:

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Gotcha so you’re just emulating a Kasa plug. Takes more patience than I have :slight_smile:

I use HA to do basically the same thing, but that just takes a few lines of code … the lazy man way:

#Emulated Kasa Devices for Sense Monitor
      name: "Hallway Lights"
      power_entity: sensor.hallway_light_power
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I already did a pcb for 240v, havent finish the programming stuff though because i just submitted the board to production yesterday however is in the works, now, that specifically device will be more similar to Sense, like a mini sense lets say, where you clamp around the supply lines, because at least in my case, those devices are energy-hungry ones, like furnaces, minisplits etc

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@andre one other thing you might want to consider would be changing the title of the post to “Custom build outlet plug for energy reporting to Sense” since the device doesn’t help with native device detection. Just my 2 cents.

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I aggree on that, i will try to set the case on fire to see what happens xD

I am also on it as well, do you mean, a normal plug to detect both power lines? Or a clamp based monitor a-la sense?

I shared this build with a lead on our Hardware team who confirmed that this is a fire hazard, especially since you’re using this on a 175w 3D printer.

Specifically, the thin copper is a concern.


I will take note of course, this is really valuable feedback:)

just poking around, in case anyone is interested, I have an almost ready version for 220v with both lines being tested, and of course the wattage info is made available in sense, which is my main priority :slight_smile:

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This is looking much more like what I’d hoped someone would build commercially, just needs a bit of packaging and the approvals (if it gets wired in)

Sense SERIOUSLY needs a 240v sensor module for “wire in” devices…the ones that consume most of the power in most homes and seem to defy Sense’s detection algorithms. The re-purposed solar system node both eliminates a capability many of us do use and doesn’t provide enough circuits.

My home has seven 240v devices, only one of which Sense has (sort of, and not reliably) detected, and we do have 8KW solar. We have 174 electric devices at last count and, as an “all electric” home up here in NH, we consumed 22,345 KWH so far in the past year. We should be an ideal customer for Sense. Unfortunately not.


Be aware that those clamps are only rated to 30amp which is on the low end of what most 240 devices pull. Amazon does have the higher amp clamps available.

I think everyone agrees with you here. I don’t think anyone at Sense has come out and said point blank, here’s why we don’t have this… My guess is that it has to do with the hardware capabilities of the monitor. For me they had to increase the polling limit to keep my monitor from crashing/locking up with only about 20 Kasa plugs and 40ish Hue devices. Even through my polling is increased I still experience lock ups on a monthly basis.

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> Note: This is a potential fire hazard and is not recommended by Sense and/or volunteer moderators in the Community.

Hello guys, I have a 240v version working with sense, there is a video here Sense energy monitor diy add-on for 240v - YouTube, I added an oled screen, and I am attaching a picture here in case you dont want to see the video,

Have a nice weekend, (still working on the case with UL)

I’m confused.

That’s a 120V plug and the screen is reading either 120.0 Volts or 126.0 Volts :man_shrugging:t3:

That is indeed a 126v plug, but in my case BOTH lines are hot lines, meaning, 126v each line with a total of +/-250v, in the screen I specified, 126v meaning each line, which if I need to use it for simpler appliances I can do so, however you are right, i will now add some extra code to auto-identify whether is a simple 126v or a 240v device