Voltage calibration in openbeken CB2S/BK7231N/BL0937 - how to perform?

Name: Voltage calibration in openbeken CB2S/BK7231N/BL0937 - how to perform?
Uploaded: 2026-01-03T18:48:50+01:00
Description: Welcome. I have just started playing with IoT, I bought two WiFi sockets with energy metering. One of them I reflashed on openbeken 1.17.419. The socket uses the CB2S/BK7231N and BL0937 module (as far as I can trust what the flasher reads from the original Tuya firmware). Everything works fine -...

Question

Welcome. I have just started playing with IoT, I bought two WiFi sockets with energy metering. One of them I reflashed on openbeken 1.17.419. The socket uses the CB2S/BK7231N and BL0937 module (as far as I can trust what the flasher reads from the original Tuya firmware). Everything works fine -...

max4elektroda · Accepted Answer

In order to calculate the energy per day, the device must know when a day starts or ends; hence, the time of the device must be set.
(See the message on the GUI).
If your device has internet access, you can enable NTP (statrdriver ntp) and it should be working.
If not, to get a roughly calculation you might set the device time "by hand" with "TIME_settime <epoch = seconds since 1970>".
Since there is no regular correction of the time which might drift it might become off for some seconds or minutes over the time...

Regarding "SetupEnergyStats" it needs this arguments (see here in docs):

[enable 0 or 1] [sample_time[10..90]] [sample_count[10..180]] [JsonEnable 0 or 1]

JSONEnable is optional.

max4elektroda · Accepted Answer

For the command use

SetupEnergyStats 1 60 60 0

Enable, 60 sec intervals, 60 samples, no JSON

(I also was not sure, so just looked up in the code)

For me the calibration works as expected:

p.kaczmarek2 · Answer

There are two ways to perform energy measurement calibration in OpenBeken:
1. You can use the commands VoltageSet , PowerSet , CurrentSet , whose names and syntax are the same as in Tasmot. We calibrate analogously to Tasmota.
Here you have a list of commands:
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/commands.md

2. You can use a GUI overlay downloaded from Github, i.e. open Web App and under Tools 2. Tools is Calibration :

Basically in the paragraph Calibration it is written in English what to do. This overlay uses the aforementioned commands anyway VoltageSet and so on, simply packs them into the HTML form

For real measurements (current, voltage, power) for the VoltageSet/PowerSet/CurrentSet commands you can at least use a second unflashed socket you have or some other meter. I recommend using a classic 60W tungsten bulb as a test load.

I am creating multiplatform open source firmware (Tasmota replacement), right now supporting BK7231T, BK7231N, XR809, BL602, W800, W600, LN882H and soon supporting RTL and W701:
https://github.com/openshwprojects/OpenBK7231T
If you like my work, support me at: https://paypal.me/openshwprojects

Helpful post? Buy me a coffee.

leśny_ziutek · Answer

I have a problem with VoltageSet, CurrentSet in 1.18.62 running on TOMPD-63WIFI:

Error:CMD:cmd VoltageSet NOT found (args 235)
Info:CMD:[WebApp Cmd 'VoltageSet 235' Result] Unknown command

Error:CMD:cmd CurrentSet NOT found (args 0.323)
Info:CMD:[WebApp Cmd 'CurrentSet 0.323' Result] Unknown command

p.kaczmarek2 · Answer

These commands are only available for the devices that you calibrate, i.e. devices with BL0947, BL0937, etc. If you have a device using TuyaMCU, the calibration option is not available, as in this case it is the MCU (additional microcontroller) that handles the energy measurement and reports to the WiFi module the already finished numerical values.

Calibration in firmware is available because when you change the firmware of the WiFi module you lose the factory calibration, but this is only true for devices with BL0947/BL0937. For devices with TuyaMCU, we do not lose the factory calibration.

I am creating multiplatform open source firmware (Tasmota replacement), right now supporting BK7231T, BK7231N, XR809, BL602, W800, W600, LN882H and soon supporting RTL and W701:
https://github.com/openshwprojects/OpenBK7231T
If you like my work, support me at: https://paypal.me/openshwprojects

Helpful post? Buy me a coffee.

python25 · Answer

Strange situation: I have various energy measurements, and there is no energy consumed today. I have the total, I have from the last hour. It is not possible to add this in HA to the window with energy consumed, because there the parameter energy today is required. All the Tasmotics I have expose this parameter, and here it does not. Can this be changed somehow in the configuration?

p.kaczmarek2 · Answer

Are you using SetupEnergyStats?

python25 · Answer

No, I did not use Added after 1 [minute]: How do you use this? Added after 1 [minute]: This much I can see.When I type this SetupEnergyStats with parameter 1, it pops up that there is no such command

python25 · Answer

I'm too stupid for that but maybe one step at a time:

Enable:
0 - disabled
1 - enabled
Sample_time - is this the length of time the measurement should last? what is 10 ...90, minutes of an hour?
Sample_count - I don't quite know what this is for, how many such time intervals should there be? But per day, per hour?

In addition, the measurement calibration is somehow strange: you can set the voltage "V", you can set the current power "W", but the current "A", unfortunately, does not respond to changes. Interestingly, even though it shows 222.5V 1A, the power it actually shows is that consumed by the device 375W.

python25 · Answer

Ok, thank you for your help, I seem to be doing the same thing and with me the amps don't change, it shows 1 A all the time

Voltage calibration in openbeken CB2S/BK7231N/BL0937 - how to perform?

Post #1

Post #2

Post #3

Post #4

Post #5

Post #6

Post #7

Post #8

Post #9

Post #10

Post #11

Didn't find an answer? Ask Artificial Intelligence

Topic summary