SVCALL(SD_BLE_GAP_CONNECT,

[wbporow]

I'm trying to understand example "ble_app_hts" how after advertising make a connection. I didn't see in code any call of function "sd_ble_gap_connect" ? how is made connection ?

[bjorn-spockeli]

The SoftDevice API uses SuperVisor Calls( SVCs) to exposes the functionality of the SoftDevice , this is stated here in the S130 SoftDevice Specification.

The SoftDevice is delivered as a precompiled binary and the SVCs are used to expose the SoftDevice functions without having any link-time dependencies between the application and the BLE protocol stack.

[bjorn-spockeli]

The events are the feedback you get after calling the SoftDevice API( i.e. functions with sd_-prefix). You need to handle the events passed from the SoftDevice in the application, e.g. once a peripheral has connected you will get the BLE_GAP_EVT_CONNECTED event. If the connection times out then you will get a BLE_GAP_EVT_TIMEOUT event. You use the logging interface to print status/errors to a terminal.