I have a Digi i.MX6UL starter kit and a HRM strapped to my chest. If I fire up bluetoothctl I get:
[NEW] Controller 00:04:F3:06:D8:AF cc6ul [default]
[NEW] Device 00:15:83:EC:AA:39 RWOODHAM2
[NEW] Device 62:80:E1:00:7B:88 Geonaute BLE HRM
[bluetooth]# connect 62:80:E1:00:7B:88
Attempting to connect to 62:80:E1:00:7B:88
[CHG] Device 62:80:E1:00:7B:88 Connected: yes
[CHG] Device 62:80:E1:00:7B:88 Paired: yes
[Geonaute BLE HRM]# list-attributes
[Geonaute BLE HRM]#
I can get the Geonaute to work with a competitor product (so I think the chest belt is working OK), why not on yours?
On the competitor the version is 5.43 I think, so not so very different.