Can I flash Tasmota or ESPHome on the stock WBR2/W701 module?
Not today. The WBR2 (RTL8720CF) lacks published SDK hooks for third-party firmware, so popular tools like Cloudcutter fail [Elektroda, piotrszulc1, post #20846308]
[WBR2/W701] Unsupported MaxCom Smart Breaker SHSB111W10
TL;DR
- Teardown of the Maxcom SHSB111W10 smart breaker, a cheap Tuya-style switch that looks like a Sonoff classic but uses a WBR2/W701H Wi‑Fi module instead of ESP.
- Inside it uses a 5V 005DC-HS QYT73 relay, fuse, varistor, input filter, BP2905 step-down supply, and an AMS1117-3.3V regulator.
- The breaker sells for as little as 40 PLN, and its module pinout matches TYWE2S-compatible boards such as ESP-02S, CB2S, and WR2.
- An ESP-02S swap could make Tasmota possible, but the SHSB111W10 is not supported by the firmware yet and still is not truly cloud-free.
Generated by the language model.
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Hello, today a short presentation of another Tuya gadget, this time combined with a warning, because this gadget is built on a WiFi chip for which there is no open software available at this moment. Inside the SHSB111W10 we find the WBR2, or W701H chip, a KM4-core microcontroller with 256KB SRAM and 2MB Flash. I will describe its internals here, and the possibility of swapping the WiFi module with another one from ESP, so that Tasmota can be uploaded.
Purchase SHSB111W10 .
This Maxcom gadget is very cheap, you can buy it for as little as 40 PLN, and it is available in various Polish online shops:
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From the outside it resembles the Sonoff classic, but there is no ESP inside.
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This is what it looks like in practice:
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Instructions, including a description of the pairing:
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Screw terminal protectors:
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Interior of SHSB111W10 .
The casing is held in place by snaps.
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The actuator is a relay at 5V, 005DC-HS QYT73, besides that you can also see a fuse, a varistor, an input filter, and part of a transformerless power supply, more precisely a small step-down converter.
The underside of the PCB will tell us more:
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The power supply mentioned is implemented on a BP2905, I couldn't find its datasheet, but it's probably a similar circuit to this one:
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Apart from that, there is also an AMS1117-3.3V, LDO regulator.
Well, and a WiFi module:
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Outputs:
| Pin number | Symbol | IO type | Function | Function | |
| 1 | 3V3 | 3V3/ | Power supply pin (3.3V) | ||
| 2 | A19 | I/O | GPIOA_19, PWM hardware, IC Pin40 | ||
| 3 | GND | P | Power supply reference ground | ||
| 4 | A18 | I/O | GPIOA_18, PWM hardware, IC Pin39 | ||
| 5 | A13 | I/O | GPIOA_13, UART0_RXD, which is used as a user-side serial interface pin | ||
| 6 | A17 | I/O | GPIOA_17, hardware PWM, IC Pin38 | ||
| 7 | A14 | I/O | GPIOA_14, UART0_TXD, which is used as a user-side serial interface pin | ||
| 8 | A20 | I/O | GPIOA_20, common GPIO, IC Pin1 | ||
| 9 | A12 | I/O | GPIOA_12, PWM hardware, IC Pin26 | ||
| 10 | EN | I/O | Enabling pin, which works at the high level and is pulled up and controlled by a user externally | ||
| 11 | A11 | I/O | GPIOA_11, hardware PWM, IC Pin25 |
The outputs are compatible with TYWE2S, so you can swap the WiFi module for one with ESP<spanclass="notranslate"> .
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The ESP-02S can be purchased for a dozen gold:
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This is a very popular module format, compatible by pinout with CB2S, FL_M99_V1, TYWE2S, TYZS6, TW-02, WR2, WB2, WBR2, WR2E, WB2S, WA2 andXT-BL02.
Summary .
The product is cheap, but so what? It won't make it cloud free anyway. This is only for Tuya supporters.
The best thing would be to get something from ESP, e.g. buy the original Sonoff, after all it's not expensive either, so no need to complicate things.
Or use e.g. Qiachip smart Switch which is on BK7231N and you can upload OpenBeken:
https://www.elektroda.pl/rtvforum/topic3874289.html
Alternatively, you could solder out the WBR2 and solder in an equivalent on an ESP, e.g. ESP-02S or compatible, but this is unlikely to be financially worthwhile.
Anyway - the SHSB111W10 is not supported by my firmware at the moment, but I intend to look into it soon.
p.kaczmarek2 wrote 14444 posts with
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Comments
As a warning - I also came across this chip in an Ineox LZWW-3 power strip. Cloudcutter didn't work, so I decided to open it up, and there it is, the W701H, plus it's on an unmarked module, so you don't... [Read more]
Is it OK to post in English here? Or should I create a new topic on the English forum? In South Africa, this exact device is sold at Communica https://www.communica.co.za/products/smart-switch-basic-wifi-tuya-10a?variant=39250494881865... [Read more]
Interesting to see an RTL8720CF in use. I wonder if any Tuya devices on Ali have WBR2s, I don't think I have one. [Read more]
https://www.elektroda.com/rtvforum/topic4093142.html - RTL8720CF development underway [Read more]
Now supported: WBR2, WBR3, WBRU, W701-VA2-CG pinout, datasheet, flashing for Home Assistant [Read more]