This tool captures Bluetooth Low-Energy (BLE) Advertisements from Polar Vantage watches. It will detect Polar Vantage watches using the Complete Local Name advertisement unless the user provides the MAC address of the watch. Then, it will listen for Manufacturer specific advertisements which encode the heart rate and print the heart rate.
Polar Vantage watches will broadcast BLE Advertisements when selecting
a sport profile. For example, the watch will broadcast you heart rate
when Indoor cycling is selected. Broadcasting is enabled by default
for certain sport profiles (e.g., Indoor cycling). You can customize
and select which profiles will broadcast through the Polar Flow App
(option HR visible to other devices). Note that you don't need to
start recording, it's enough to select the activity (Start training ->
Indoor cycling).
The tool will not show the current heart rate unless you have selected a sport profile which is configured to broadcast measurements.
My Polar Vantage M (firmware ver. 5.1.8) broadcasts 3 different types of BLE Advertisements:
Complete Local Name(9): This is the model of the watch followed by the serial number. The tools uses this advertisement to determined if this is a Polar Vantage watch if the user hasn't specified the MAC address to listen to.Flags(1): This is a 16b field which I haven't been able to interpret yet, in my watch this has the value of 04. For now, the tool ignores it.Manufacturer(255): This is a manufacturer specific advertisement. In my watch it has the following format:Most bytes don't change.6b00720872acf50200000000XX00YYYYis the heart rate in hex.XXis the expended energy in cal since the last measurement.