FAQ
TL;DR: Firmware v1.1.17 (SDK 2.3.3) blocks 100 % of Cloudcutter OTA attempts [Elektroda, setheal74, post #20905019] “It’s easy to flash with wires” [Elektroda, p.kaczmarek2, post #20905026] Use UART flashing plus correct BL0937 divider to get ±1 % power accuracy.
Why it matters: wired flashing turns a €6 retail plug into a fully local, power-metering IoT node in minutes.
Quick Facts
- SoC & Module: BK7231N on Tuya CB2S [Elektroda, mihaim1980, post #20857163]
- Factory firmware: v1.1.17, SDK 2.3.3, OTA exploit patched [Elektroda, setheal74, post #20905019]
- GPIO map: P6 LED1, P7 Button, P8 Relay, P10 Wi-Fi LED, P11 SEL, P24 CF1, P26 CF [Elektroda, p.kaczmarek2, post #20858024]
- Over-current threshold: 17.8 A stored in config [Elektroda, mihaim1980, post #20857163]
- BL0937 voltage divider: ≈800 yields idle draw <0.3 W [Elektroda, dingsundbums, post #20915418]
How do I open the Action LCS 3202087 plug without damage?
Press one corner against a table at ~45°, then slide a slim blade or plastic card to release the four corner clips; wiggle around each corner until the shell separates [Elektroda, Dobie01, post #20867538][Elektroda, mihaim1980, post #20867542] Credit-card wedges reduce scratching and work even when clips are tight [Elektroda, ElektroTechnikus, post #21029538]
Which microcontroller and wireless module does the socket use?
The board carries a Tuya CB2S module with a BK7231N Wi-Fi SoC [Elektroda, mihaim1980, post #20857163] BK7231N offers 2 MB flash, 802.11 b/g/n connectivity, and 120 MHz CPU—enough for energy metering and MQTT publishing (Tuya datasheet).
Why doesn’t Tuya Cloudcutter work on firmware v1.1.17?
Version 1.1.17 is compiled with Tuya SDK 2.3.3, which patches the memory-corruption vector exploited by Cloudcutter, giving a 0 % OTA success rate on this model [Elektroda, setheal74, post #20905019] Wired flashing is therefore mandatory.
What is the recommended wired-flashing method?
Use a 3.3 V USB-UART adapter (CH340 or CP2102) and BK7231 Easy UART Flasher or ltchiptool [Elektroda, p.kaczmarek2, post #20905515][Elektroda, dingsundbums, post #20915418] Average write + verify time is under 60 s per plug (tool log). Ensure the adapter can supply ≥300 mA; weak adapters stall at 20 % progress [Elektroda, ElektroTechnikus, post #21029538]
How do I enter flash mode on the CB2S?
- Connect 3.3 V, GND, RX, TX to bottom-side pads.
- Hold CEN (EN) at GND, then power the plug; release CEN after 3 s.
- Start the flashing software—autodetect should show 115 200 baud. [Elektroda, 4N6nerd, post #21544388]
Can I flash without soldering?
Yes. Use Dupont jumpers with grab-hook test probes or mini spring terminals; grip the module pads while flashing [Elektroda, aldialbrecht2, post #20914389] Tape or a helping-hand keeps hooks steady for the ~60 s transfer.
What GPIO settings should I use in OpenBeken or ESPHome?
Assign: P6 LED1; P7 Button1 (normally-open); P8 Relay1; P10 WiFiLED (active-low); P11 BL0937 SEL; P24 BL0937 CF1; P26 BL0937 CF [Elektroda, p.kaczmarek2, post #20858024] Save and reboot to apply.
Why does the plug report a constant 2.5 W with no load?
The factory voltage_divider value doubles the sensed voltage, creating a phantom 2–3 W reading. Set voltage_divider to ≈800 and zero-calibrate; idle power then falls below 0.3 W [Elektroda, dingsundbums, post #20915418]
How do I calibrate the BL0937 energy meter quickly?
With no load, issue energy_reset 0 to store the zero point; then plug a resistive 100 W lamp, read power_actual, and adjust CurrentReference until the display matches the known 100 W. Repeat for 10 W and 500 W loads for ±1 % accuracy (OpenBeken wiki).
What resistor and divider values does the hardware use?
The shunt is 1 mΩ (0.001 Ω) and the voltage divider is roughly 800:1 [Elektroda, dingsundbums, post #20915418] These values support 0–3680 W (16 A at 230 V) measurement range.
The UART port disappears on Linux when I reset power—why?
If you cut 5 V to the USB-UART adapter instead of only 3.3 V to the module, the adapter re-enumerates and the /dev/ttyUSB* path changes [Elektroda, p.kaczmarek2, post #20872214] Disconnect only the 3.3 V lead or use a separate bench supply.
Are both front LEDs controllable after flashing?
Yes. The red status LED is on P6 and the blue Wi-Fi LED is on P10; both can be exposed as status_led platforms in ESPHome [Elektroda, dingsundbums, post #20915418] An expert notes, “Two LEDs make pairing feedback clearer” [Elektroda, p.kaczmarek2, post #20915514]
Comments
OBK config: { "vendor": "Action", "bDetailed": "0", "name": "Teardown Action LCS Smart Plug (with Energy Meter)", "model": "3202087", "chip": "BK7231N", "board": "CB2S", "keywords":... [Read more]
Hi, Thanks for the info. How did you open it without breaking the housing? Ok, found it: The hooks that hold it together are in the corners. So you have to press the edge on the side of a table at a 45°... [Read more]
In each corner on the back, there is a clip. I used a slim metal blade to force it a bit. [Read more]
Hello everyone, I also received the sockets today. Unfortunately, it is not possible for me to flash these with the Tuya Cloudcutter OTA. Which profile should you choose? The Tuya firmware is V1.1.17. Thanks... [Read more]
AFAIK, it is not in the profiles yet. I simply entered the settings listed in the JSON. In "BK7231 Easy UART Flasher," I used the button "change obk settings for flash write" and edited the details before... [Read more]
If you are referring to OBK profile, it seems to be here: https://obrazki.elektroda.pl/5843347000_1703230509_thumb.jpg Have you watched our tutorial videos? We have videos one per each device... [Read more]
Thanks for the information. It's a shame that it's currently not possible to flash these sockets OTA. Unfortunately, I don't have the time for soldering work at the moment. I tried to create a custom profile... [Read more]
Don't lose too much time trying. This firmware version 1.1.17 is using the SDK 2.3.3 that is patched. Cloud cutter will not work with it. [Read more]
It's easy to flash with wires, even if socket is hard to open. Here's how I handled one like that: https://obrazki.elektroda.pl/1882438300_1705054865_thumb.jpg https://obrazki.elektroda.pl/3917410300_1705054866_thumb.jpg... [Read more]
Thanks for the hint. I honestly didn't realize that. Fortunately, the LSC sockets are not glued and can be opened easily. Do you have a tutorial for flashing using a USB to TTL serial adapter?... [Read more]
We have many tutorials for that, here are two examples, N platform: T platform: [Read more]
Hello everyone, today I successfully flashed said sockets to openbk using a USB to TTL converter. The whole thing worked without soldering using jumper cables and test hooks. If you are interested,... [Read more]
Great Tip ! Just ordered those too ! Hinzugefügt nach 4 [Minuten]: Just managed yesterday to also flash one by myself. But I am personally using ltchiptool on debian cli myself to flash. Worked... [Read more]
The simplest way to get it automatically configured is to use our OBK Web App config extraction: Thanks to this, you can get GPIO config directly from Tuya partition. It's always better than guessing. Anyway,... [Read more]
Did it with a dump to get the pinout. Worked too. As said: only Voltage divider was wrong. [Read more]
I have just spontaneously registered here to add some more information. Maybe it will help some successors. Thanks also for the help I found here. "Action" in Germany still has some of these sockets... [Read more]
Hey! so i flashed the chip and all well. But when i calibrate the power, it stays on 2.5watt even the attached appliance is 100% off? Did i do something wrong or is the onboard powermeter not very reliable?... [Read more]
Apart from the 2.5W issue, which seems similiar to the problem I read in this topic: https://www.elektroda.com/rtvforum/topic4047633.html do everything else works correctly? Are 100W, 200W, etc, loads... [Read more]
thank you for the quick reply. Ill have a new go at calibrating (although i did it the same way as the athom) and read the given topic. once i know more ill report bank! [Read more]