BLE Enhancement Request: Report Voltage from LYWSD03MMC Xiaomi Thermometer with ATC firmware

[rjblake]

PROBLEM DESCRIPTION

The MQTT does not currently include the Battery Voltage for the LYWSD03MMC broadcast by the device flashed with the ATC firmware. This would be beneficial to track remaining battery life as voltage drop off on the CR2032 is quite sharp and allow for early warnings on replacement.
In addition, the MQTT is rounding the Humidity value being sent (e.g. on Tasmota Main Screen shows 36.9, but MQTT is 37.0). In the case of the Custom broadcast from Victor (pvvx firmware), the Temp & Humidity are broadcast with 2 decimal places.

  Configuration output here:
15:53:23.740 MQT: stat/tasmota_5A0E24/RESULT = {"NAME":"ESP32-DevKit","GPIO":[1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,0,0,0,0,1,1,1,1,1,0,0,1],"FLAG":0,"BASE":1}
15:53:23.958 MQT: stat/tasmota_5A0E24/RESULT = {"Module":{"1":"ESP32-DevKit"}}
15:53:24.217 MQT: stat/tasmota_5A0E24/RESULT = {"GPIO0":{"0":"None"},"GPIO1":{"0":"None"},"GPIO2":{"0":"None"},"GPIO3":{"0":"None"},"GPIO4":{"0":"None"},"GPIO5":{"0":"None"},"GPIO9":{"0":"None"},"GPIO10":{"0":"None"},"GPIO12":{"0":"None"},"GPIO13":{"0":"None"},"GPIO14":{"0":"None"},"GPIO15":{"0":"None"},"GPIO16":{"0":"None"},"GPIO17":{"0":"None"},"GPIO18":{"0":"None"},"GPIO19":{"0":"None"},"GPIO20":{"0":"None"},"GPIO21":{"0":"None"},"GPIO22":{"0":"None"},"GPIO23":{"0":"None"},"GPIO24":{"0":"None"},"GPIO25":{"0":"None"},"GPIO26":{"0":"None"},"GPIO27":{"0":"None"},"GPIO28":{"0":"None"},"GPIO29":{"0":"None"}}
15:53:24.269 MQT: stat/tasmota_5A0E24/RESULT = {"GPIO30":{"0":"None"},"GPIO31":{"0":"None"},"GPIO32":{"0":"None"},"GPIO33":{"0":"None"},"GPIO34":{"0":"None"},"GPIO35":{"0":"None"},"GPIO36":{"0":"None"},"GPIO37":{"0":"None"},"GPIO38":{"0":"None"},"GPIO39":{"0":"None"}}

  STATUS 0 output here:
{"StatusSTS":{"Time":"2021-02-12T15:54:30","Uptime":"1T21:33:18","UptimeSec":163998,"Heap":115,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"Wifi":{"AP":1,"SSId":"BFIR","BSSId":"B4:FB:E4:2E:15:1A","Channel":6,"RSSI":60,"Signal":-70,"LinkCount":1,"Downtime":"0T00:00:05"}}}