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Unusual BSD33 smart socket from Vesync APP on BK7231M (batch change, interior)

p.kaczmarek2  Cool? (0)
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Smart plug packaging with CB2S BK7231M module and sender's note. .
Today I have another package on the table from a reader in Germany. This time it's an unusual smart socket, seemingly just another version of the popular LSPA9, but here distinguished by an unusual WiFi module from the BK7231M. The BK7231M is essentially the BK7231N but with different encryption keys stored in the fusebits and a different bootloader. Such a situation is characteristic of the 'Bekens' used by manufacturers other than Tuya. Such WiFi modules are not compatible with the batch compiled for the regular BK7231N, so they have to be specially handled....

The socket was sent to me with additional BK7231M modules (labelled CB2S, which suggests BK7231N) back in the days when nobody knew how to flash BK7231M. At the moment my Flasher already supports BK7231M, details:
How to flash BK7231M/BL2028N devices other than Tuya with 000000 keys? .
BK7231M also has binary batches separately compiled for this platform (under these encryption keys).

But let's start with the standard, on-package markings:
Label with contact information and certification marks on a white background. .
X001TKNBOP.
Instructions:
Vesync Wi-Fi smart plug user manual on a table. .
In the instructions, the 'Vesync APP' appears, not Tuya, which somewhat confirms the observation that the BK7231M (as a module with other keys in efuse) is used in products just from other ecosystems.

Now it is time to change the firmware. One way to open the case describes the topic:
How to open the ELIVCO LSPA9 case without damage? .
The measure resembles other LSPA9s:
https://www.elektroda.com/rtvforum/find.php?q=LSPA9
Here one of the earlier descriptions:
https://www.elektroda.com/rtvforum/topic3887748.html#19984436

So, the interior:
Close-up of CB2S module marked as BK7231M on a circuit board. .
Slot designation:
Close-up of the BSD33 socket model marking with power input specifications. .
The module is marked CB2S, but it is BK7231M. Several similar ones were sent to me by a reader:
Three CB2S modules labeled BK7231M on a table. .
Yes, when the screen is removed it is a BK7231M:
CB2S module with BK7231M chip on a blue circuit board .

Other than that flashing as standard. I soldered out the CB2S:
Disassembled smart plug with BK7231M module on a wooden table. .
All according to the flasher instructions:
https://github.com/openshwprojects/OpenBK7231T_App
You can also follow the topic about BK7231M:
How to flash BK7231M/BL2028N devices other than Tuya with 000000 keys? .
Breadboard with LED, electronic components, and three CB2S BK7231M modules. Prototype circuit on a breadboard with wires and an electronic module. Circuit on a breadboard with a WiFi module, connected via USB. .
The rest of the photos, the socket is a typical LSPA9:
Close-up of a green PCB board of LSPA9 socket with the marking BSD34-202110. Close-up of internal electronic components of a smart socket. Smart plug electronic board with identifying components. Close-up of electronic components on a circuit board with a capacitor, resistor, and other parts. .
The varistor is present, not bad. The inverter is as usual non-isolated, step down, here on BP2525, as usual. In addition to this we have here a BL0937 for power measurement. The PCB designation is BSD34-202110

After uploading everything works, but you still need to set the GPIO roles, i.e. where is the relay, where is the button, fortunately here the template from Elvico fits:
Computer screen showing ELIVCO LSPA9 socket and version description. .
Code: JSON
Log in, to see the code
.
You just need to calibrate:
OpenBekenX_E34708 user interface showing the status of a smart plug. .
According to the documentation, VoltageSet, etc:
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/commands.md
PowerSave can also be enabled.

Summary .
Thank you for the delivery!
It took a little while, but I managed to add BK7231M support to my flasher and environment, so from now on this socket can work cloudless, conveniently and with Home Assistant.
Also, thank you for giving me additional modules with BK7231M, I will probably need them for, among other things:
How to access the hardware SPI port on the CB2S? P16 (MOSI) solder to QFN .
I am very pleased to have such active readers actively participating in putting up new topics.
If any readers also come across the BK7231M then please let me know - I'm curious to know how many WiFi modules of this type are on the market.

About Author
p.kaczmarek2
p.kaczmarek2 wrote 12421 posts with rating 10288 , helped 585 times. Been with us since 2014 year.

Comments

Mateusz_konstruktor 27 Jun 2024 20:17

. Is it possible to determine by external appearance alone what type of module we find inside? Or are there groups of devices, either in terms of manufacturer or the function performed, which have the... [Read more]

p.kaczmarek2 27 Jun 2024 20:33

At the moment it looks like Tuya has its SDK under BK7231N and BK7231T and there it has one specific key written in fusebits, so if there is a Tuya product with Bluetooth then you can bet on Beken (based... [Read more]

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