Govee H5177 Bluetooth Low Energy Smart Thermo-Hygrometer

After playing with Govee thermometers H5074 and H5075, I came across the H5177 model with similar specs but with a larger display including some buttons and backlight. I decided to give it a try, just to see if it used the same protocol as the previous units.

wim@WimPi4-dev:~ $ sudo ../visualstudio/projects/GoveeBTTempLogger/bin/ARM/Debug/GoveeBTTempLogger.out -v 2 | grep E3:5E:CC:21:5C:0F
 [2020-11-09T00:26:34] 44 E3:5E:CC:21:5C:0F 06 (UUID) 0A18F5FE88EC (Name) Govee_H5074_5C0F
 [2020-11-09T00:26:34] 26 E3:5E:CC:21:5C:0F 88EC000103DE106402 (Temp) 45.842°F (Humidity) 43.18% (Battery) 100%
 [2020-11-09T00:26:35] 44 E3:5E:CC:21:5C:0F 06 (UUID) 0A18F5FE88EC (Name) Govee_H5074_5C0F
 [2020-11-09T00:26:35] 42 E3:5E:CC:21:5C:0F 4C000215494E54454C4C495F524F434B535F485750740F5CC2 (Apple) (UUID) 494E54454C4C495F524F434B535F4857 (Major) 5074 (Minor) 0F5C (RSSI) C2
 ^C* SIGINT: Caught Ctrl-C, finishing loop and quitting. *
 GoveeBTTempLogger Version 1.20201016-1 Built on: Oct 16 2020 at 12:13:28 (exiting)
 wim@WimPi4-dev:~ $ sudo ../visualstudio/projects/GoveeBTTempLogger/bin/ARM/Debug/GoveeBTTempLogger.out -v 2 | grep A4:C1:38:13:AE:36
 [2020-11-09T00:27:05] 46 A4:C1:38:13:AE:36 GVH5075_AE36 (UUID) 88EC (Flags) 05 (Manu) 88EC0002859F4900 (Temp) 61.7502°F (Humidity) 27.9% (Battery) 73%
 [2020-11-09T00:27:05] 42 A4:C1:38:13:AE:36 4C000215494E54454C4C495F524F434B535F48575075F2FFC2 (Apple) (UUID) 494E54454C4C495F524F434B535F4857 (Major) 5075 (Minor) F2FF (RSSI) C2
 ^C* SIGINT: Caught Ctrl-C, finishing loop and quitting. *
 GoveeBTTempLogger Version 1.20201016-1 Built on: Oct 16 2020 at 12:13:28 (exiting)
 wim@WimPi4-dev:~ $ sudo ../visualstudio/projects/GoveeBTTempLogger/bin/ARM/Debug/GoveeBTTempLogger.out -v 2 | grep A4:C1:38:0D:3B:10
 [2020-11-09T00:27:35] 46 A4:C1:38:0D:3B:10 GVH5177_3B10 (UUID) 88EC (Flags) 05 (Manu) 01000101029D1A64
 [2020-11-09T00:27:35] 42 A4:C1:38:0D:3B:10 4C000215494E54454C4C495F524F434B535F48575177F2FFC2 (Apple) (UUID) 494E54454C4C495F524F434B535F4857 (Major) 5177 (Minor) F2FF (RSSI) C2
 ^C* SIGINT: Caught Ctrl-C, finishing loop and quitting. *
 GoveeBTTempLogger Version 1.20201016-1 Built on: Oct 16 2020 at 12:13:28 (exiting)

While I was able to see the device data in Bluetooth advertisements, it’s got some differences. The code snippets above are cherry picked from one device each that I know how to interpret and the new device last.

The Manufacturer data in the new H5177 device doesn’t start with the same 88EC signature, but at least appears to be the same length as H5075, and one byte shorter than the data packet from the H5074.

17.1C 28% matches with (Manu) 01000101029D1664. If anyone can point me to a quick decode algorithm, I’ll update my project to support this device very quickly.