Our experience with buying "brand new" Tuya modules like CB2S, CB3S, WB2S (BK7231T, BK7231
We've been recently looking for a way to buy brand new Tuya modules, especially CB3S/CB2S (BK7231N) and WB2S (BK7231T). BK7231N is a bit newer and has more advanced support in OpenBeken (deep sleep and WS2812B), so it was our primary focus. Here I will write down our experience.
Our modules were ordered from a Chinese reseller, the unit price is about 2% per piece, we weren't sure whether they are reused or resold by Tuya, so we decided to make some tests.
First module we'll test is WB2S:
It comes in a nice strip form:
We've checked the flash content with out flasher:
https://github.com/openshwprojects/BK7231GUIFlashTool
Suprisingly, something is there:
This device already contains a SmartLife flash dedicated for something that looks like a RGB lamp with extra Relay, Button and WiFi LED. It even has specified PWM frequency. It must have been dedicated to run in some smart device...
Then we also flashed OBK:
https://github.com/openshwprojects/OpenBK7231T_App
OBK access point shows up correctly:
And it's possible to configure OBK easily:
Second module we'll test is CB3S:
There is again something in the config:
The config specifies a reset pin (button) on P9, a WiFi LED and both IR receiver and IR transmitter. It seems that this device was a smart IR remote module/repeater that could receive, learn and send IR signals.
Again, we've tried to flash OBK on that - no problems:
Firmware dump:
https://github.com/openshwprojects/FlashDumps/commit/33924c257d8da78f0578341232158a95091f804d
Third module we'll test is CB2S:
This time modulke seems to be coming from a BL0937 smart socket. BL0937 pins are clearly visible in the config. There is a also a Button, a Relay and WiFi LED.
Firmware dump:
https://github.com/openshwprojects/FlashDumps/commit/8e607e800c7e2a1b7b507ddfb7ab29f92aeba462
Conclusion: the bought Tuya modules seem to come from some Tuya production line. They already have flashed specific Tuya firmware for a given device type (like a RGB light, or a power metering plug, or an IR bridge) and are ready to be soldered inside it. They also contain already calibrated RF partition and work good with OpenBeken, so we haven't found any downsides to that. Hopefully they will be useful for us in our DIY projects.
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Comments
In summary, are surplus stocks sold that have not found their way into end-use equipment? Pre-prepared and with batch. Could there be any private data, wifi network names, passwords? [Read more]
It does indeed look like surplus stock, or at least something created initially with a different purpose. Surely, as if connecting a button to a pin defined in Tuya's JSON from the batch it would be possible... [Read more]
I use a PowerShell script to convert an entered plain-text string into hex then which then checks my bins for credentials. I was thinking about posting it for others, but not sure if that's a good idea.... [Read more]
If it searches for the string that you already know, then it's not that bad actually. Still, anyone willing to extract unknown SSID/pass from dump is still most likely to figure out the way on their o... [Read more]
indeed. lmk if you want a new short topic on it. or if you're thinking of making one now. [Read more]
are there any modules to buy at the moment ? digging through aliexpress the cheapest I manage to find on BK costs over 6zl, cheaper is even esp32 you can get. This should cost as much as nothing, considering... [Read more]
XH-WB3S i.e. BK7238 on Ali I've seen for £4, and yes you'd have to look for cheaper deals. Maybe @divadiow will know something more. And what do you need the modules for? [Read more]
I don't know much about bulk ordering modules. SparkleIoT have a 1688 store though and they sell the module from there https://detail.1688.com/offer/811437204979.html I've not bought from 1688 before,... [Read more]
to be placed as sensors around the house and garden. There will be about 50 of these. The ESP32 draws a bit too much power, and the 8266 is old and will not handle the matter. Some detectors would probably... [Read more]
WB3S BK7238? [Read more]