Best device for measuring Power?

[kappuchino]

Hi, I'm trying to contribute the Philips Hue Signe table & floor light (4080148P9 & 4080248P7) which happen to stand around in my living room ;-).

I've got the fine docker construction working, and have three power measuring devices lying around: A nous powerplug converted to tasmota 10.1, a shelly 1pm and a shelly 1pm plus with original software. My questions:

• Which one would be the best in your experience to measure it most precise?
• I usually do calibrations with a 60watt bulb - or should I use something different for that?
• Should I run each of the three types (hs, color_temp, brightness)?
• Anything else I should consider/check when running the power measurment?

Thank you in advance.

[bramstroker]

Hi, I'm trying to contribute the Philips Hue Signe table & floor light (4080148P9 & 4080248P7) which happen to stand around in my living room ;-).

Hi that's great!

I've got the fine docker construction working, and have three power measuring devices lying around: A nous powerplug converted to tasmota 10.1, a shelly 1pm and a shelly 1pm plus with original software. My questions:

• Which one would be the best in your experience to measure it most precise?

I only have experience with the Shelly Plug S myself. Want to purchase some more smart plugs to do some comparence, but did not find the time (and budget) to realise this.
I would suggest you try with all 3 options one time and see which one behaves the best and seems most accurate. Than we can also use your opinions / experience to advise other contributors.

• I usually do calibrations with a 60watt bulb - or should I use something different for that?

What do you mean by calibration? Most smart plugs are already calibrated afaik and don't have an option to recalibrate with a device with some known wattage, right?

• Should I run each of the three types (hs, color_temp, brightness)?

Depends on the supported color modes of your light. You can also check that in HA developer tools.
When you have a light which only allows to be dimmed, than only brightness is needed.

• Anything else I should consider/check when running the power measurment?

Not really, just try it out and see what results you get.

[kappuchino]

Hi that's great!

Well, I'm happy to contribute.

I only have experience with the Shelly Plug S myself. Want to purchase some more smart plugs to do some comparence, but did not find the time (and budget) to realise this. I would suggest you try with all 3 options one time and see which one behaves the best and seems most accurate. Than we can also use your opinions / experience to advise other contributors.

Will do. I might need insight to make sense from the data.

• I usually do calibrations with a 60watt bulb - or should I use something different for that?
  What do you mean by calibration? Most smart plugs are already calibrated afaik and don't have an option to recalibrate with a device with some known wattage, right?

Well, I am referring to the tasmota power calibration and setting a modifier for shelly if the consumption is/would be off. Classic Bulbs are quite "spot on" on their consumption rating. So I use a 60W Bulb to check.

• Should I run each of the three types (hs, color_temp, brightness)?
  Depends on the supported color modes of your light. You can also check that in HA developer tools. When you have a light which only allows to be dimmed, than only brightness is needed.

Ah. Maybe a hint would help in the script. I ran all three. Any side effects on the data from this?

• Anything else I should consider/check when running the power measurment?
  Not really, just try it out and see what results you get.

Already working on it. With three measurements each step and three devices to run it on, I should have the data in a couple of days.

Cheers,
Kappuchino

[kappuchino]

Hm. Showstopper: Docker construct crashes (I) with the shelly plus 1pm, python native (II)seems to have issues with python 3.10.0 ... will post error output later.
Error I:
en/powercalc-measure:latest
Powercalc measure: v0.14.1

2022-01-15 12:25:31,464 [INFO] Selected powermeter: shelly
2022-01-15 12:25:31,499 [INFO] Selected Light controller: hass
? Select the color mode? hs
? Do you want to generate model.json? Yes
? Specify the full light model name Philips Signe LED Table-Lamp (4080148P9)
? Which powermeter (manufacturer, model) do you use to take the measurement? Shelly, Shelly Plus 1PM
? Do you want to gzip CSV files? Yes
? Are you measuring multiple lights. In some situations it helps to connect multiple lights to be able to measure low currents. No
? Select the light? light.tischleuchte
? What model is your light? Ex: LED1837R5 4080148P9
2022-01-15 12:27:36,927 [INFO] Measuring standby power. Waiting for 20 seconds...
Traceback (most recent call last):
File "measure.py", line 517, in
main()
File "measure.py", line 514, in main
measure.start()
File "measure.py", line 144, in start
standby_power = self.measure_standby_power()
File "measure.py", line 287, in measure_standby_power
return self.take_power_measurement(start_time)
File "measure.py", line 248, in take_power_measurement
measurement = self.power_meter.get_power()
File "/app/powermeter/shelly.py", line 17, in get_power
json = r.json()
File "/usr/local/lib/python3.8/site-packages/requests/models.py", line 910, in json
return complexjson.loads(self.text, **kwargs)
File "/usr/local/lib/python3.8/site-packages/simplejson/init.py", line 525, in loads
return _default_decoder.decode(s)
File "/usr/local/lib/python3.8/site-packages/simplejson/decoder.py", line 370, in decode
obj, end = self.raw_decode(s)
File "/usr/local/lib/python3.8/site-packages/simplejson/decoder.py", line 400, in raw_decode
return self.scan_once(s, idx=_w(s, idx).end())
simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Error II:
Traceback (most recent call last):
File "/Users/dave/Projects/powercalcT/utils/measure/measure.py", line 19, in
from light_controller.hue import HueLightController
File "/Users/dave/Projects/powercalcT/utils/measure/light_controller/hue.py", line 6, in
from PyInquirer import Separator
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/PyInquirer/init.py", line 6, in
from prompt_toolkit.token import Token
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/init.py", line 16, in
from .interface import CommandLineInterface
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/interface.py", line 19, in
from .application import Application, AbortAction
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/application.py", line 8, in
from .key_binding.bindings.basic import load_basic_bindings
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/key_binding/bindings/basic.py", line 9, in
from prompt_toolkit.renderer import HeightIsUnknownError
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/renderer.py", line 11, in
from prompt_toolkit.styles import Style
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/styles/init.py", line 8, in
from .from_dict import *
File "/Users/dave/Projects/powercalcT/utils/measure/measure/lib/python3.10/site-packages/prompt_toolkit/styles/from_dict.py", line 9, in
from collections import Mapping
ImportError: cannot import name 'Mapping' from 'collections' (/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/collections/init.py)

[bramstroker]

I am looking into modifying the tool to support both API versions. Need to have some additional information as I don't have this Shelly module. When you request http://192.168.x.x/status/ on your Shelly Plus 1PM do you get a 404 HTTP status code or 200?

[kappuchino]

It's 404. (Verfied via Firefox-Developer Tools and Charles Proxy).

GET:
scheme http
host 192.168.1.15
filename /status/
Adresse 192.168.1.15:80
Status 404 Not Found
VersionHTTP/1.1
Übertragen 122 B (9 B Größe)

[bramstroker]

Thanks. I just merged PR #500 into master. Are you able to test with the master version, will be published to docker hub soon by github action.

[kappuchino]

Sure ... Noob Question: How can I check when the update to docker has occured?

[bramstroker]

https://hub.docker.com/r/bramgerritsen/powercalc-measure/tags. You will see here the master tag has been updated 2 minutes ago, so should be ready to go now. You'll need to do a docker pull first to make sure you fetch the latest version to your local cache.

[kappuchino]

Bummer. While it pulled a new docker:
Using default tag: latest
latest: Pulling from bramgerritsen/powercalc-measure
72a69066d2fe: Already exists
758aab0c7b73: Already exists
1db83a6395ee: Already exists
b3b8b56b0660: Already exists
513cdf2c811a: Already exists
83c21aea088f: Pull complete
0a67621cdcf7: Pull complete
c7fbae9734bd: Pull complete
0a641296fbf2: Pull complete
Digest: sha256:f32f0200df5a4e142682954f6ad99e0652a52bf93d33f723adea51501d41ad57
Status: Downloaded newer image for bramgerritsen/powercalc-measure:latest
docker.io/bramgerritsen/powercalc-measure:latest

It also gave an error:
2022-01-16 11:13:38,828 [INFO] Measuring standby power. Waiting for 20 seconds...
Traceback (most recent call last):
File "measure.py", line 517, in
main()
File "measure.py", line 514, in main
measure.start()
File "measure.py", line 144, in start
standby_power = self.measure_standby_power()
File "measure.py", line 287, in measure_standby_power
return self.take_power_measurement(start_time)
File "measure.py", line 248, in take_power_measurement
measurement = self.power_meter.get_power()
File "/app/powermeter/shelly.py", line 17, in get_power
json = r.json()
File "/usr/local/lib/python3.8/site-packages/requests/models.py", line 910, in json
return complexjson.loads(self.text, **kwargs)
File "/usr/local/lib/python3.8/site-packages/simplejson/init.py", line 525, in loads
return _default_decoder.decode(s)
File "/usr/local/lib/python3.8/site-packages/simplejson/decoder.py", line 370, in decode
obj, end = self.raw_decode(s)
File "/usr/local/lib/python3.8/site-packages/simplejson/decoder.py", line 400, in raw_decode
return self.scan_once(s, idx=_w(s, idx).end())
simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

[bramstroker]

You have "bramgerritsen/powercalc-measure:latest", this one has not been updated yet, will only be updated when I do an actual release. You will need "bramgerritsen/powercalc-measure:master". So you need to change the docker run command to match this version.

[kappuchino]

I'm sorry. Already retrying.

[kappuchino]

👍✅🍾 works fine! Just waiting to reach the consumption threshold now.

[kappuchino]

Yup, once the shelly picks up a load > 1,8 Watt it is logged in the output. Well done, thank you so much!

[bramstroker]

Great! Happy measuring ;-)

[kappuchino]

So ... I've been reading about professional power measuring equipment because my readings in the first few watt range is always 0 or really random. But this equipment costs (justified or not) in the high hundrets and few thousands. Sigh.

And then I started to see what the "asian market" has to offer. Found two today that are of interest:

• The ZHURUI PR10 (in its variations for different Outlets) has only manual readings (on the display) and "hacking" it would either void the warrenty or require a camera and digitizing it with cam2ocr. (Examples can be found at Amazon and AliExpress)
• The HiDANCE EU Plug AC220V Power Meters has a bluetooth connection + apps that seems to be usable for direct access. The current price is around 25€ ... which seems to good to be true (or a fire hazard or both ...). On the other side it seems it is a price worth paying to try, so I ordered one and will see how it can be used, especially for low readings.
  There might be more or better suited devices. I'll keep searching.

Sorry for the clutter in this discussion btw, I'm not really used to github (yet).

[bramstroker]

I appreciate your efforts in search for a power meter which will accurately measure low power.

In my experience I have troubles measuring power lower than 0.4 watts with my Shelly Plug S. Values higher than that are picked up fine and seem accurate. Others have similar experiences with other smart plugs (i.e. Tp-link kasa).
For most lights this is not really an issue as the power draw even on the lowest brightness is higher than that.

You mentioned that your Shelly Plus 1PM is only picking up power higher than 1.8W, which is really high and so this device seems unsuitable for taking measurements.

I'm not skilled enough (and have electric / hardware knowledge) to take on the task of making ZHURUI PR10 smart. Maybe someone else have the skills, otherwise we will need to search for a complete solution, preferably WiFi and with an internal API.

How was your Nous plug with Tasmota doing?

[kappuchino]

I appreciate your efforts in search for a power meter which will accurately measure low power.

In my experience I have troubles measuring power lower than 0.4 watts with my Shelly Plug S. Values higher than that are picked up fine and seem accurate. Others have similar experiences with other smart plugs (i.e. Tp-link kasa). For most lights this is not really an issue as the power draw even on the lowest brightness is higher than that.

Since I had so many Nous/Gosund Plug-In Sockets I never considered Shelly Plugs until now. Will get one to compare.

You mentioned that your Shelly Plus 1PM is only picking up power higher than 1.8W, which is really high and so this device seems unsuitable for taking measurements.

Weirdly, all my measuring tech seems to have issues with values below up 5 Watts - either erratic values or not picking them up at all.

I'm not skilled enough (and have electric / hardware knowledge) to take on the task of making ZHURUI PR10 smart. Maybe someone else have the skills, otherwise we will need to search for a complete solution, preferably WiFi and with an internal API.
Ah, I mentioned it as a means of comparing values since people have tested it against much costly equiptment and it turned out to be quite good.

How was your Nous plug with Tasmota doing?
See above - really off or zero until the light was near its max power around 8 Watts and more. Since I did not keep the original firmware, my guess is they all suck at low watts/loads. Except the shelly, which will arrive in 2 days. Maybe then I'll figure something out.

Oh and I will try out what baseload will change (i have some 25W -> 100W Lamps to add to the load form the zigbee lamps) + will run the power soft on some "known" bulbs/lamps which I happen to have.

[kappuchino]

Okay, I got a shelly S Plug today and tested it with the 4080148U9 Signe Table light using the brightness from 1 to 255. The data is visibly inconsistent ... so more to test and to find out. See graph and attached data. I'll use more plugs and measurements soon.

(fw1 = original firmware, fw2 = newst firmware - noload starting at 0W vs. 75W baseload, which I subtracted before computing)

[kappuchino]

As far as I have read the manuals of these devices they log the data by the second or by change, so syncing it would be doable!

[bramstroker]

Ok that's perfect. Let's see how it works in practice. I started working on adding the time column see #505. Didn't have the time to complete it now, have to go. Will finish the development soon.

[bramstroker]

I have added the option for datetime column.
You can add CSV_ADD_DATETIME_COLUMN=True to the env variables.

This is in the master branch, so you should pull that one from docker for now, as you did before. Will be released in v0.16.0

[kappuchino]

Awesome. I have some peak workload tomorrow, but the weekend should have time to test and measure. :-)

[kappuchino]

Note: See post below - I waited till the "better" measuring device arrived so I would not have to work twice. I'll now test the devices against each other (measuring differences across typical loads).

[kappuchino]

Hi. I've recieved the long awaited power monitor ordered via ali-express. And seems to have all the details that are missing in my opinion from the power-plugs - from low watt measures to excel measurements export ;-). Oh and it cost only 25€ for the device, vat, duties and shipping. A steal, I think!

I've included some images here:
First: The device is not electrically safe by european standards (afaik): The connectors are open in the middle and can be easily touched. Not safe around children , people who put their forks everywhere and drooling cats.

Second: As a remidy (since I have a drooling cat) I connected a travel-adapter that covers the whole area and also connects the safety line to the plug on top. As you can see, the power of the gosund device is measured around 0,8 w ... and thats really good and close.

Also, I opened it up to see if there are "intenal" hazards on the pcb or connectors that can be used ....
Surpise! Everything seems to be neatly separated and there seems to be a serial connector as well that I will try to figure out.

Last but not least:
There is a bluetooth connection to a measuring app - I'll figure out how to link those to the fine software here and then I'll be good to go.

[bramstroker]

That's awesome, how can they make it for this price.

I have bought myself a ZHURUI PR10, but as you said it only allows for manual measurements. I use it to check for correctness of lower power reading of the Shelly plug, and to get the standby power when the shelly is unable to measure it.

[kappuchino]

That's awesome, how can they make it for this price.

In search for an answer: Most likely standard parts in scale (my guess is that the hardware is less than 15€ maybe even around 10€, but still decent quality) and liberal electrical requirements. The nearly exposed middle socket is really something ...

I have bought myself a ZHURUI PR10, but as you said it only allows for manual measurements. I use it to check for correctness of lower power reading of the Shelly plug, and to get the standby power when the shelly is unable to measure it.

From the outside the ZHURUI is the correct design for Safety ... and it might even have certifications for that. And the vendor has other devices for precise measurements of bulbs and such in its catalog, so I guess they share the same quality design.

Right now I'm tinkering with the bluetooth stack to get it to record the data direcly on my computer ...
(Sidenote: The app e_tester seems to be the general app for all bluetooth power measure devices on aliexpress like this one for usb ... maybe someone already reversed the protocol. I think i research that first ...)

[davlaw]

While this thread is somewhat stale, it covers some questions I was having myself.

My arsenal contains the PR10 as well, was using it as my master to calibrate Sonoff s31 with Tasmota. But I'm finding that the Sonoff, like the others, does not do well with the lower measurements and I think I may sense some day to day stability. And having a 60 watt bulb dummy load hanging around the bench is no fun.

Guess 2 questions;

Any known online resources to plunder through?
Anyone using Shelly Plus PM Mini Energy Meter. I already have flashed Tasmota on it, but the power chip-set is different than the Sonoff.

But I'm clueless which would be better.. I just rediscovered the shelly plus pm in my pile of devices.

[GH2user]

@kappuchino this wifi/bluetooth desk unit is still for sale on AliExpress for slightly less than 30euro now. I think the main difference with the PR10 is that it is not showing the energy graph over time on the display.
Can you recommend it for low power measurements or did you switch to something better?

[davlaw]

Using card from https://circuitsetup.us/product/expandable-6-channel-esp32-energy-meter/?v=1d7b33fc26ca

Which makes me think current transformer is the secret sauce here. I have been trying several with various differences. But so far all are able to measure low wattage.