WSD400H Tuya Temperature & Humidity Monitor Model Differences Between AliExpress and Alibaba

Hello,
I have flashed a WSD400H tuya temperature and humidity monitor : https://french.alibaba.com/product-detail/HOT...Desktop-Wall-Mounting-Low-11000008227998.html
I Buy mine a long time ago on Aliexpress, I don't know if they are the same model now.






It' easy to flash like all other CBU board.

I can receive the Temperature and Humidity with a firmware with SHT3X driver for ht30 sensor

insmod wrote:

>>21551107 If you have a github account:
https://github.com/openshwprojects/OpenBK7231T_App/pull/1601
https://github.com/openshwprojects/OpenBK7231...actions/runs/14426556455/artifacts/2934386864

I do not have the display working, I don't know how to use the BL55028 driver for the display, maybe somebody can help?
The SDA is connect to P15 and SCL to P17 of the CBU
I don't use the battery I power the device thru USB

Quote:

{
"vendor": "Tuya",
"bDetailed": "0",
"name": "WiFi Temperature Humidity sensor",
"model": "WSD400H-A006",
"chip": "BK7231N",
"board": "TODO",
"flags": "1028",
"keywords": [
"TODO",
"TODO",
"TODO"
],
"pins": {
"7": "SHT3X_SCK;0;0",
"8": "SHT3X_SDA;1;2",
"9": "Btn;0",
"15": "SoftSDA;0",
"17": "SoftSCL;0",
"28": "Rel;4"
},
"command": "startDriver SHT3X",
}

AI: Can you tell us what firmware or platform you are using on the WSD400H (like Tasmota, ESPHome, or something else)?
OpenBK7231N_1601_merge_4e0edb709da7.bin
AI: When you try to use the BL55028 driver for the display, do you see any error messages or does the display show anything at all (like staying blank, flickering, or something else)?
Anything, only blank

patbonamy76 wrote:

I don't know how to use the BL55028 driver for the display

There is no driver for the BL55028. The closest I think I can see is the idea of one for the BL55070 being floated here https://www.elektroda.com/rtvforum/topic4000657.html#20725443

>>21575838
Thanks for your help, unfortunately this doesn't help there's not Tuya MCU on the board.

This is I2C device, it requires a custom driver. I can create one, but i would need to have this device on site.

Datasheet (BL55028_V1.3_en.pdf):
BL55028_V1.._en.pdf Download (233.13 kB)

>>21580230
Sorry for the delayed response, thanks for your help, I cannot leave you the device I leave in France.
Can you explain how can I do it myself.
Have a great day