DIY ESP32 AC Power Meter (with Home Assistant/Automation Integration) 

This is exactly what I need, thanks! Now I can monitor how much power I'm drawing from my neighbour's power grid and adjust my load so it won't make any suspicion.

Hey! This video doesn't start with the word "recently" 😅😅

The circuit shown at 6:42 is a nice idea and definitely works in a pinch, but it's a serious source of error in your measurements and can easily DESTROY your expensive ESP32. Firstly it relies on the precision and drift of the offset voltage resistor divider, which is not insignificant as if you are using 5% resistors, your center voltage and thus powerline measurement could also be off by 5% (or around 16v at line level). Also at startup, before the 10uF capacitor charges to 1.65v, the input of the ADC swings negative, which can seriously damage some devices which don't have stringent input protection. Finally, if there is some fault in the line which causes the transformer to output a higher than expected voltage, this will exceed the power rail of the circuit and discharge straight into the ESP32. You want a circuit called a "Clamper" or "DC Restorer" which will fix your voltage above ground potential (protecting the ESP32 ADC) and allow you to take advantage of the full scale of the ADC input. This also saves on two precision resistors for the voltage divider, and a rail-to-rail buffer amplifier will tend to isolate the ESP32 from any voltages over the supply rails. With an output buffer you can also use a smaller capacitor value, with higher voltage rating and non-tantalum type for safety such as a ceramic disk capacitor. You can also safely add an external ADC if you want to increase your measurement accuracy substantially. (Just remember to sample the max voltage to calculate the zero crossing point for the AC signal, as there is no center offset voltage now) There is no fundamental difference between your expensive power meter and a circuit you can build at home, you just need to find all your sources of error and minimize them! :) Here is example circuit for reference tinyurl.com/y2aoed7z

If you want to save energy, just turn off the light strip in the background (0:15), Scott! Jokes aside, great project!

this dude read my thought i wanted to do that exact thing

My Sunday morning is complete... Coffee and *GREAT SCOTT!!*

"which is handy and SHOCKING at the same time" me: i see what you did there

"Handy and shocking." A pun across two languages. I love it

Part of the error in the measurements is due to the crappy adc of the esp32

Wouldn't be one of the eastron meters an option? I use the sdm630 which is connected via modbus to a raspberry pi. The values can be published via mqtt.

I can reccomend shelly devices, most of them have power meter feature integrated, there are aswell a dedicated powermeter wit power clamps. Even 3-phase is available. And they can be integrated very useful 👍

what a coincidence! have to start to Programm a esp32 Bluetooth audio receiver like... now

I have built one of these, but with an Arduino Nano. Works pretty good, though not very accurate, especially with low power usage. So I decided to go the Esp32 route. But the built-in ADC resolution is still too low. Which I went with an ADS1115, which gives me 16-bit resolution. Problem is, I can't get the ADC to properly work with the EmonLib code. I've even done the procedure injection, or what ever it's called and made the changes for it. Still nothing. And the guy who originally made the altered code for the ADS1115 with EmonLib won't help. Any ideas on how to get these to work together? I know the ADS1115 can only do about 800sps. To get "real" power consumption, need at least 1500sps or something like that. But it'd be better than the built-in ADC. Also to note, the standard EmonLib can only do about 4 return values per second, and this is because it does several loops per run to get the values. This does slow down the returning values quite a bit.

Some points from my experience building The same thing for my own home: if you can't find a 12-volt AC former, you can step down the voltage just using a standard voltage divider with 10 or 20 times the resistance on the upstream resistor (depending on if you're in the Europe or US). If you want it isolated, you can use a one-to-one speaker transformer, or they have potted transformers the one-to-one ratio specifically for this task. Also the ESP32 ADC has abysmal accuracy without some sort of filtering in software. I actually used an Arduino nano to measure the current on the two phases coming into my house (US) and pass that off to an ESP8266 to send to my server. The values I got out of this setup were within 0.1% of what the electric company said I used.

I had something like that in mind for a long time, great job!!! Adding a temperature sensor on a solar heater and a power relay we could remotely power on its internal resistor when we need it (without have it on all the time). We can also watch the power consumption for security reasons and be able to turn on the outside lights remotely, and so on. Home (and not only) automations with microcontrollers is so simple this days and we can do so many things that really worth spending some time learning how to program them which is pretty simple and a great way to learn children how and why programming is fun and why maths physics and chemistry is necessary most of the time on whatever we do :-)

I think your problems with such diffrent values is the non-linearity of the ESP32s ADC. There is alot of stuff about this on google. The best thing so monitor the values all the time is to use a Shelly 3EM and integrate it into your hass

Great vid as always! Just one question, if you used a current transformer that supports up to 5A how are you going to measure the power for your whole house with it? Surely the house draws more than 5A and that could destroy the transformer

I have literally no idea what I'm watching But I still love his videos :)

Power meter: shows -43W real power Great Scott: "the power meter still works perfectly fine"

The CT Clamp component in ESPHome is based of the emonlib library and has very easy integration, it even allows you to use a higher precision external ADC such as ADS1115.

The more easier way is probably using the pzem-004T module with an esp-01...maybe a future project? :D

I just installed Home Assistend on my Proxmox Server and was searching for a "smart" Power Meter I could use with it, perfect timing :D

Hey, nice video, like always

8:40 how do you calibrate these values? Do you need a 1000€ power meter to find the right values? 😱

I think I better not to know how many power I'm using. I like big number, if I could see it, i might turn on something unnecessary to drive up the number.....

I'd like to hear more about the circuit at 6:40 that scales the AC voltage and shifts it to be above the ground reference used by the ADC.

Hi! I tried this method but I ends up using the PZEM-004T or HLW8032. It shows more efficiency since I have one dedicated chip to measure the power and let the ESP32 to register and casting the data. The only problem that I found is that I don't know how to find if the power factor is capacitive or inductive. They just show me the power factor, without a positive or negative sign =/ Otherwise is perfect.

Will it not be easier to use tasmota or espeasy?

Nice Project but one thing strikes me about it. Is the RealPower supposed to be negative? @ 10:42

I want to be like you when I grow up fully (hehe I am teen )......EXPERT IN THIS FIELD..... any tips plz? :D

I'm using energy meter with pulse output wired to esp8266 and just counting pulses during time. Class 1 IEC 62053-21 45A 230V 1000imp/kWh - everything is simple. Paid 54PLN (~14USD).

The ADC of esp32 is not accurate enough

Good​ job.​ I​ recommend IC​ : Ade7753​

Great video as always, But I have a question, would the transformer not influence the phase of the measured votlage? Wich will make the power factor and active power not precise . Or was that accounted for in the code ?

Can someone explain why you need the voltage sensor? Isn't a current clamp enough?

There is a simplier solution for power measuring which is called PZEM-004T (with great accuracy of measurements too!)

You should add a money had to pay by you for electricity , it will be shown in your home assistant

What a great energy you delivered while saying " stay creative and see u next time"

I had a doubt Scott, why dont you use ACS712- Current sensor and ZMPT101B- Voltage Sensor and make it as simple as possible and well portable as well with no external circuits as well?

Very interesting video. GreatScott never disappoints! I made a similar circuit with the CS5490. Have you calculate the accuracy of the measurements with your multimeter?

What about using an optocoupler as a reference point for timing?(zero voltage detector as an interrupt)

If you got one of the newer electricity meters just count the light pulses it emitts and calculate the power drawn

exactly what i needed thanks!!

Thanks for the helpful video

I love how popular Home Assistant has become.

Great construction :) Unfortunately, here in Sweden almost 2/3 of my energy bill is made out from static taxes and grid fees.... This would be ok in an apartment - but me and my GF live in a fairly big house of our own, where the main heating is electrical (deep ground heat exchangers to heating water circulation). If I cut my actual consumption of energy by 99%, my electricity bill would only go down by maybe 35% :(

I've recently done this myself, well similar. I wrote my own code in the IDF and used the SCT-013 current clamp so I could measure the whole house current. No touching of live wires needed since it's a clamp rather than pass through doughnut. Works very well but I am assuming voltage since I don't have an isolating transformer yet to measure it. That's the next upgrade!

Very good video. I liked it

Can I know your smart phone model ? Heheh, Am familiar with almost all models but this type seems different 😅.

Is there some source code ? github ? I would like to see more videos abaout HomeAssistant !

Its super cool , but its really difficult when you start. For beginners point of view, various topics like working of esp32, how data came into mobile app, current sensor calibration etc are alot of things to learn. 🤖 All the best to all and do share your experiences. 👍

GreatScott! glosses over a summation formula that probably has most viewers' eyes glazing over. "And just like that..."

Some of the new/Modern US home power meters actually have debug output ports. You can hook into those if you want, they are read only and not encrypted in any way. So this may be even easier to access the data.

Hey what about the Tesla coil you have talked in the yt stories???

how about another project for a 24 or 48V system to measure current and voltage i.e from a battery

Hi Scott, you should definitely do a follow up and some finalization of this. I need to do exactly this, but the situation is that I want to see each of the info about consumption per beaker, so the question is, do I need to have ESP for each of the breaker? Or is there possibility to combine them? A lot of questions which I think you've been working on in the past, so your experience would come in handy. Thanks

I actually just received my very first ESP8266 NodeMCU in the mail yesterday and have been pondering a project all night. Amazing that you post this today!🤘🏼🤘🏼

Have you used the same hall sensor in your home distribution box as the one in the beginning of the video? That hall sensor can only measure up to 5A which sounds short. Love you vids btw! :)

Skip 06:00 to 06:05 if you like to live dangerously

honestly i expected some electroboom moments

It was really weird to not hear :hi there

I'm running two circuits, one with grid power supply only (high-power appliences) and another with fail-over from an inverter/battery that has low power appliences and all lamps. I also need to monitor battery charging and discharging currents with voltage, so I could measure efficiency and battery health. I think one current sensor would be enough on battery +ve terminal ; should give -ve values when charging and +ve when discharging.

My version of the ESP power meter using PZEM-004T and ESP-12F (ESP8266) github.com/viperet/esp8266-power-monitor

6:46 it is day 19 of me watching Arduino hobbyists on RU-vid. I have still yet to see someone who doesn't solder like a psychopath. Either use the perfectly good breadboard you have it plugged into, or remove the headers and solder to the holes (with the stripped wire going THROUGH the hole). For some reason nobody on RU-vid can figure this out.

Great video as always👍😀 Thanks for sharing👍😀

It looks stupid, really. A step down transformer + voltage divider + ADC on ESP... Heavy solution and metering accuracy is not sharp I guess. Much easier to connect pulse or data output from power metering unit.

Greeting Compliments for the job. I follow you constantly on youtube and now I have subscribed. But I have to tell you something without getting angry. In my country it is said: When you get a good seed, keep it and propagate it because it is worth a lot. That goes for you too. Make as many children as possible because there are so many stupid people in the world today that it is rare to find someone like you. Once again, compliments and greetings from Serbia.

Here's the thing. Turning electronics on and off cost them longevity. I've owned a 48" Samsung Smart Tv for over 5 years and it was already a few years old. I've never turned it off. I have 4 other tv's that are newer that got shut off constantly and they lasted for no time. But. I'm learning how to refurbish them.

I would suggest to use those Hilink 220v to 3.3v AC-Dc converter for directly run esp from mains

I really want to see that tesla coil. I've been watching your videos since i first started electronics about three years ago. I still cannot believe that you didnt make a tesla coil that can make some interesting arcs.

I love my cheap electricity. Never have to worry about wasting my time on this.

This is what I've been wanting to do, though A) I want to do every circuit so I need about 30 channels of sampling, and B) I don't really care that much about precise values, calculating reactive power, getting RMS values, etc. I just want some relative values so I know what circuits to go after as hogs next, or which can be adjusted to run primarily in the daytime when the solar panels are producing.

I wonder how accurately you make your projects ....

This is neat, but there's an easier way to do this. Check out the circuit setup energy meter, which is compatible with esphome right out of the box. I put together a complete system for under a hundred bucks using his stuff.

for semi diy: use an SDM230 and read it with an esp via modbus.. pretty acurat ;)

5 Amps looks quite low... even a toaster can reach 1100W.

Ypu let me down on this one Scott. Needed more explaination..Especially on the code...good job anyways..

your beard style looks good

You must have used a more generalized component for stepping down the voltage similar to the CT

The average power consumption is rather high compared to what? Regarding private households the energy consumption lowered from >4500kwh to like 3500-3000kwh for 4 persons since 2002 in Germany (Energieverbrauch Abschlussbericht BMWI 2002). And thats without electrical water heating and without electrical heating. As a lot more people tend to have multiple of those crappy electric heating devices in

Hi brother ... Can u please tell me what is the best replacement for NJM5532D DUAL OP AMP.. because I didn't found njm5532d so please suggest me better replacement ic (microphone booster project)... How about NE5532D DUAL OP AMP

06:42 what's this circuit please mention the name of this one

This may be off-topic but can't seem to find any updated information on the subject. Have managed to build a sprinkler controller and a couple of temp monitors for around the house. Using ESP8266 dev kit and the ESP8266 Wemos D1 Mini. But have been struggling with creating a cell phone app with buttons and other display items. I did find cell phone app programming software called Blynk. Unfortunately, I don't know why it dropped from popularity well I kind of do. If you ever decide to create a video on Blynk I would surely watch and possibly donate to the cause. I have watched many videos and many have stated it is easy to use. But upon further discussion, most if not all are based on a simple button that has an on/off capability. I think if you try and used this software you will spot the failed sections of the process as I have. Really would like to be able to control things from my cell phone as in ESP 8266 devices. Fingers crossed you take a peek at this and decide to do some videos on this subject. Oh, and BTW there are many videos online for BLYNK but they are either of poor audio quality or years old.

I have a question about the esp32-s2-wroom-1 series... and maybe the esp32 in general. I am completely new to programming and got this for my birthday. After some libraries and coding I have gotten an hc-sr04 and a dht-11 working together to output data to the arduino serial monitor... my question is on WiFi do I have to do the network and password or is there a way to just communicate wireless without a network??? I haven't really done much with programming before??? Thanks for any replies!!!

Not sure why, but my outputs are just massively off... I can adjust the calibration number to get it to match, but then as soon as the current changes the output is again massively off.. Using esp32 with ads1115 and the standard emonlib library, but with a slightly modified calcIrms function to take an array of readings from the ads1115 as an input variable, instead of using the built in ADC.

I tried to do the same with esp32, but I couldn't. I made the compilation and transferred it to esp32 and when I try to visualize it on the serial monitor, it just shows random data from any... I tried several rate speed combinations.. 9600, 115200, but nothing. Could you help me?

If you have a smart meter (which a lot of people have nowadays in Germany and the Netherlands) you can hook up a RPI to the P1 port of the meter. That port spits out a lot of info about your electricity and gas usage (if you have gas at your home). You can also integrate it very easy with Home Assistant.

I am waiting for this video for a long time. The most informative video on this topic on RU-vid Thanks sir

I did exactly this but found the ADC on the ESP32 to he horrible. Despite it being 12-bit, the Arduino was far more accurate due to its linearity and lower noise. When I get a chance, I’m going to use the ADS1115 that can be purchased on Ali Express for a dollar or two.

Great explanation of how different loads effect the phase angle between Voltage and Current BUT to keep things simple with respect to monitoring power consumption (as charged on your power authority account) have you considered just monitoring the pulsing LED on your power meter. I suggest this for one of your excellent RU-vid videos.

This is one element of my thesis paper on college. Those stressful days.

Hey Scott, nicely done ✌️ Will you please tell Hey is Nodmcu is capable of reading sinusoidal waveform ?

I always imagined, by the voice I was listening , That he would be a very elegant British guy or a blond boy, but he looks Latin or maybe from the Middle East, I don't know, There's nothing offensive, just like that, I hope I don't disturb anyone.

Lol "handy and shocking" made my day😆

The ESP32 ADC has significant non-linearity. I don't know whether this is fixed in firmware now, but a few years ago it was a big problem. Just FYI.

I was going to ask you for a vid on what oscilloscope to buy for tinkering like you. Then i saw the part number on this vid and searched for the one you use, holy shyte, thats a 12000 euro oscilloscope. ok nevermind, i'm gonna keep using my multimeter like the noob i am. good vid btw, as always

I think this is project where is better to buy, than DIY. You can get modbus/mbus 3phase energy meter for 50eur. Look at tme.eu It have tons of measurements... Not to mention it is safer... Your safety transformer probably cost as much.

You can just buy sonoff pow r2 for 11 euro and reprogram it via esphome. it does actually the same, but can handle 10A cont./16A peak, has built-in relay, and you do not need to write your own code and build the device

This is cool I did this the far using cheep aliexpress bluetooth AC meters. But not as small as this one.

Hi, May be a stupid question: I have got solar panels and I would like to measure the power going home from grid but eventually the one going out when solar production is greater than consumption. For that I need to identify the direction of current. Do you think this is feasable ? Thanks for advise.