I have been doing some test with my Garmin HRM Pro Plus, that I think clarify how Garmin HRMs can be used with alphaHRV
- Using ANT for alphaHRV and BLE for the native device’s connection
This configuration works normally. The sensor sends RR-int values, so that alphaHRV can process the data.
Although it could be enough for cycling, runners are missing all running metrics in their Garmin watches, because they are only transmited in ANT mode. - Using BLE for alphaHRV and ANT for the native device’s connection
In this case, running metrics are available in the Garmin watch, but alphaHRV is stuck at “Collecting data …” usually at 0%. The reason is that the sensor behaves as a simple HRM that only provides HR values, but not RR-ints, so alphaHRV shows HR values, but it can’t collect data needed for DFA.
This was weird because it is clear that Garmin sensors are able to provide RR-ints and from time to time, I have received these data even in BLE mode. When you subscribe to HR notifications, there’s no way to specify that you are expecting for whole data including HR + RR-int. It’s the sensor who decides what to send.
It seems that in case of communication with CIQ apps, Garmin HRM enter into this minimum data transmission mode when they detect some “traffic jam” can occur and they open complete data transmission otherwise.
Considering this, I have managed to use BLE successfully for alphaHRV, disabling bluetooth on my phone just before starting alphaHRV (the HRM Pro plus is paired with the phone by GCM even if you are not using this app in foreground). In this way, the sensor activates full data transmission. Then you can enable again bluetooth in the phone.
In case that the phone is far away or you hadn’t added the HRM to GCM, BLE should work normally.
Please, confirm that this also works for any of you using Garmin HRM Pro Plus and even for new sensors like HRM200 and HRM600