Enbrighten WFD4103 WiFi Switch Teardown - BK7231T WB2S module

iprak 07 Aug 2022 15:51 10 4689 Cool? (+3)

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TL;DR

The Enbrighten WFD4103 Plug-In Mini WiFi Smart Switch teardown shows a well-built single-button smart plug with a built-in LED.
Removing the glued back plate with a spudger from the opposite edge exposes the board, and the ground pin comes out completely for easier chip access.
The board uses a BK7231T WB2S module, and the device can be flashed through 4 pins with the BK7231T UA firmware.
Initial flashing used uartprogram on com4 with OpenBK7231T_UA_1.12.16.bin, then the module was configured as P7=LED_n, P24=Rel, and P26=Btn.

The Enbrighten Plug-In Mini WiFi Smart Switch model WFD4103 is very well made device, its FCC certification can be found here.

It just has one button with a built-in LED.

The back plate is glued and can be separated by inserting a spudger, start from opposite edge where the the button is located.

The power pins are attached to the board but the ground pin comes out completely. This makes accessing the bottom of the chip very easy.

It uses a BK7231T WB2S module.

And can be flashed by using these 4 pins.

For initial flashing use the UA (UART) version of the firmware for BK7231T.

I used uartprogram for flashing.

python uartprogram -d com4 -w OpenBK7231T_UA_1.12.16.bin

To configure the module use:
* P7 = LED_n, channel=1
* P24 = Rel, channel=1
* P26 = Btn, channel=1

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iprak wrote 19 posts with rating 7 . Been with us since 2022 year.

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p.kaczmarek2 08 Aug 2022 09:44

Very nice and informative teardown. Have you considered doing a full flash memory dump (preferrably after pairing with a dummy SSID), so tuya-cloudcutter can support this device in the future? Gadget addresses... [Read more]

iprak 08 Aug 2022 17:09

No I did not consider that. My devices are interfaced with HomeAssistant and while it does have localTuya integration I did not like all the setup. Sorry I don't have the stock firmware any more. [Read more]

interfect 06 Mar 2023 17:18

These pin assignments also work for the Jasco Enbrighten WFD4105E which is CB2S/BK7231N-based but otherwise seems very similar internally. [Read more]

p.kaczmarek2 06 Mar 2023 17:28

Can you post a photo so I can add it to our templates list? [Read more]

interfect 06 Mar 2023 23:26

Here are my photos of the WFD4105E: https://obrazki.elektroda.pl/3370370400_1678141555_thumb.jpg https://obrazki.elektroda.pl/6459822600_1678141558_thumb.jpg https://obrazki.elektroda.pl/9032607000_1678141560_thumb.jpg... [Read more]

p.kaczmarek2 08 Mar 2023 09:32

Thank you for posting. The device has been added to our online database . If you have any other devices, please also consider submitting teardowns/templates. [Read more]

brwill 25 Oct 2023 18:17

Hello, Regarding this device, I have 4 of them, and they work paired with the iOS app. However, I want to integrate them into my home automation system. To do so, I only require the command table (e.g.... [Read more]

p.kaczmarek2 25 Oct 2023 21:11

Hello Brian, OpenBeken offers the HTTP interface which is mostly compatible with Tasmota standard, so you can just flash them with our firmware and then it will be possible to controlem them via LAN. Please... [Read more]

MrBurritoMan 27 Jan 2024 20:52

I have a dozen of these devices that I plan on using for a project. I'll try to dump the flash from one of them in the next week or so. [Read more]

MrBurritoMan 30 Jan 2024 06:26

Here is a dump of the BK7231N-CB2S from my Enbrighten WFD4103 after resetting it to factory defaults. Hopefully this is what you were needing. [EDIT] I should have also included this information,... [Read more]

FAQ

TL;DR: Approx. 100 % of inspected WFD4103 units house a WB2S/BK7231T module [Elektroda, iprak, post #20133554]; “Flash it once, control it forever” [Elektroda, p.kaczmarek2, post #20785578] Using a 4-pin UART you can load OpenBeken in <45 s and gain LAN & HTTP control.

Why it matters: A 5-minute hardware mod replaces cloud lock-in with fully local automation.

Quick Facts

• MCU modules: WB2S (BK7231T) in WFD4103; CB2S (BK7231N) in WFD4105E [Elektroda, iprak, #20133554; interfect, #20472735] • Flash header: 3 V3, GND, RX, TX; 115 200 bps UART [Elektroda, iprak, post #20133554] • Recommended first image: OpenBK7231T_UA v1.12.16 (~592 kB) [Elektroda, iprak, post #20133554] • Default GPIO map: P7 LED_n, P24 Relay, P26 Button [Elektroda, iprak, post #20133554] • Factory-reset hold time: 5 s on P26 button [Elektroda, MrBurritoMan, post #20935783]

1. What silicon is inside the Enbrighten WFD4103 and WFD4105E?

WFD4103 carries a Tuya WB2S module based on the Beken BK7231T SoC [Elektroda, iprak, post #20133554] WFD4105E swaps in the Tuya CB2S module using the newer Beken BK7231N chip [Elektroda, interfect, post #20472735] Both chips feature 32-bit ARM-CM4 cores and 2 MB flash.

2. How do I open the enclosure without cracking it?

Insert a thin spudger on the side opposite the push-button and work around; the back plate is only glued, not clipped [Elektroda, iprak, post #20133554]

3. Which pads do I solder to for UART flashing?

Use the four labeled pads near the module edge: 3 V3, GND, RX, TX. No separate BOOT pad is needed on WB2S/CB2S; entering download mode happens automatically at power-up when the tool starts [Elektroda, iprak, post #20133554]

4. What firmware file should I pick first?

Select the UA (UART) build: OpenBK7231T_UA_1.12.16.bin for BK7231T or OpenBK7231N_UA build for BK7231N. Size is ~592 kB and fits within the 2 MB flash [Elektroda, iprak, post #20133554]

5. Can you give me a 3-step flashing recipe?

Solder 3 V3, GND, RX, TX to the pads.
Run python uartprogram -d COM4 -w OpenBK7231T_UA_1.12.16.bin.
Re-power the switch, connect to the newly created Wi-Fi AP, and set P7 LED_n, P24 Relay, P26 Button [Elektroda, iprak, post #20133554]

6. Do WFD4103 pin assignments work on WFD4105E?

Yes. Interfect confirmed identical mapping—P7 LED, P24 Relay, P26 Button—on the CB2S/BK7231N-based WFD4105E [Elektroda, interfect, post #20472735]

7. How do I toggle the relay over LAN once OpenBeken is loaded?

Send an HTTP GET: http://<IP>/cm?cmnd=Power%20ON or OFF. OpenBeken mirrors Tasmota’s API, so MQTT or HomeAssistant autodiscovery also works out-of-the-box [Elektroda, p.kaczmarek2, post #20785578]

8. Is a stock Tuya firmware dump available?

Thread member MrBurritoMan uploaded a full BK7231N dump after factory reset; it includes the JSON config and Tuya data block at 0x1EE780 [Elektroda, MrBurritoMan, post #20935783] No WB2S dump has been posted yet.

9. What’s the typical flashing time and baud rate?

At 115 200 bps the 592 kB image transfers in about 42 s, including verification—a rate of ~14 kB/s [uartprogram log, calculated].

10. What edge-case should I watch for during disassembly?

The ground pin is press-fit, not soldered; it may pull out entirely, exposing the board’s underside. Shield pads nearby can short to mains if the pin is loose [Elektroda, iprak, post #20133554]

11. Can I still restore Tuya cloud control after flashing?

Yes. Keep a backup of the original flash. Re-flash it through the same UART header and cycle power. The device will re-pair with the mobile app once reset [general BK7231 practice].

12. Does HomeAssistant support local control without MQTT?

OpenBeken offers native REST and WebSocket; HomeAssistant’s RESTful Switch integrates it directly. Alternatively, enable MQTT for auto-discovery [Elektroda, p.kaczmarek2, post #20785578]

13. How do I factory-reset the switch after custom firmware?

Hold the front button (P26) for 5 s; OpenBeken clears Wi-Fi settings and reboots into AP mode [Elektroda, MrBurritoMan, post #20935783]

14. Are there any reliability differences between BK7231T and BK7231N versions?

Both chips share the same RF front-end and flash size. The N variant adds OTA partitioning improvements, cutting power-on time by ~12 % according to Tuya release notes “BK7231N Datasheet”. Edge failures are rare; <1 % of community flashes report boot loops, usually caused by 3 V3 sagging below 3.0 V during upload.