Format for Humidity Data Changes Randomly

[mikecy1953]

I recently purchased 2 new LYWSD03MMC that came with firmware 2.1.1_0159 installed. Successfully flashed both with the ATC_Exploit and they work except I have encountered an odd situation.

I have a Python app running on a Raspberry Pi4B that uses BleakScanner.discover function to retrieve the ATC advertisements. Periodically the advertising format will change for the humidity data. Sometimes the format will be as described in the Readme.md file where Byte 13 is the Humidity in percent and Byte 14 is the Battery in percent. Other times the format for the Humidity is int16 (Bytes 13-14)) and Byte 15 is Battery. This happens with both devices and it appears to be completely random. It will broadcast in one format for a while and then revert to the other format.

The data appears to be accurate regardless of which format it is broadcast in so I can work around the problem by determining which format the data is broadcast in and decode accordingly. But I am curious whether anyone has any insight into what is going on.

I used the following custom settings when flashing the devices:
Smiley: Off
Advertising Type: Custom
Sensor display: in °F
Sensor advertising: in °C
Show battery in LCD: Enabled
Advertising interval: 1 Minute