Mi Smart Standing Fan 1X: Supported by swapping MHCWB4P-B for ESP-WROOM-02D

[haydenmc]

Hi there,

I love this project and have a half dozen Mi devices running esphome.

I recently purchased a Mi Smart Standing Fan 1X and was disappointed to see it was utilizing a non-ESP MCU for wireless connectivity, preventing me from flashing esphome.

The board looked awfully similar to the one that was in my other standing fan, the "Mi Smart Standing Fan 2," and on closer inspection I saw that the weird module in there would be pin and package-compatible with an ESP-WROOM-02D:

Xiaomi MHCWB4P-B:

ESP-WROOM-02D:

The Standing Fan 1X is listed in the miot spec database, so I figured there was a good chance it was using the same serial protocol as usual.

I ordered the ESP module, wrote a YAML config per the miot spec, flashed and installed the module in place of the original, and it worked like a charm!

The only slight hiccup is that the antenna on the ESP module doesn't extend entirely past the ground pour on the board, so the signal strength suffers a bit. If I were to do this again, I'd source the ESP modules with an IPEX connector and attach a tiny external antenna.

I'd be happy to open a pull request to document the process and provide my esphome configuration file, but I want to inquire about if and how the repo owner would like that information presented - the README is currently home to a list of "unsupported" devices that use a similar Xiaomi MCU.

Thanks for all of your work maintaining this resource!

[scrampker]

Super cool!