bluetooth lowenergy - Can Scanner know the advertising channel?

Question

As described, BLE Scanner can not know the advertising channel.

How to get BLE advertising channel index number

But, in the link below, at first graph,

the Initiator send the CONNECT_REQ to the Advertiser through Ch.38 which is used to send ADV_IND.

it is something like that the Initiator knows which the advertising channel is used.

https://microchipdeveloper.com/wireless:ble-link-layer-connections

Can Scanner know the advertising channel?

Answer 1

The scanner of course knows which advertising channel is being used. It's just that it's not part of the Bluetooth Specification to expose this information to an application using the Bluetooth stack. In particular, the HCI events for advertisements do not contain such a field. It is possible though that some embedded devices can expose this info to the application, if they have defined a custom API for this.