Start by checking that Bluetooh is enabled on your smartphone.
Then check that you have authorized the BikeCompanion application to use Bluetooth.
On iOS, in “Settings”, look for the “BikeCompanion” app:
Under Android, in “Settings”, look for the “BikeCompanion” application:
Then check that “Nearby devices” is set to “Authorized”.
You also need to make sure that your sensor has battery power, and that it’s not already associated with another device or application on your phone.
For example, if you have a Polar watch, an H10 belt and your smartphone, you need to launch the application and associate with the belt before launching the activity on the watch, otherwise the latter will be associated with the belt and prevent association with your phone.
The same applies to the Garmin Varia radar, which must not be paired or connected with any other application or device, including the Garmin Varia application, as the radar can only be connected to one application at a time.
If your device was previously associated with BikeCompanion, you can also try to delete the device on the BikeCompanion App, and then add the device again.
As a last resort, you can quit the application, restart your smartphone and repeat the operation.