samples: Bluetooth: update scanning_while_connecting sample

Update bluetooth softdevice controller configuration
to achieve faster connection establishment.

Signed-off-by: Henrik Lander <[email protected]>

Author: henrla

samples/bluetooth/scanning_while_connecting/README.rst

@@ -182,7 +182,7 @@ The result should look similar to the following output::
    I: Connected to FB:92:1D:8E:8C:D8 (random), number of connections 14
    I: Connected to D9:E5:51:E0:5E:24 (random), number of connections 15
    I: Connected to CF:2F:99:89:A3:4D (random), number of connections 16
-   I: 12 seconds to create 16 connections
+   I: 8 seconds to create 16 connections
    I: Disconnecting connections...
    I: ---------------------------------------------------------------------
    I: ---------------------------------------------------------------------
@@ -204,7 +204,7 @@ The result should look similar to the following output::
    I: Connected to F4:9C:8C:24:F9:44 (random), number of connections 14
    I: Connected to EF:92:DC:88:3B:B3 (random), number of connections 15
    I: Connected to C8:BA:1D:6F:95:2B (random), number of connections 16
-   I: 9 seconds to create 16 connections
+   I: 7 seconds to create 16 connections
    I: Disconnecting connections...
    I: ---------------------------------------------------------------------
    I: ---------------------------------------------------------------------
@@ -226,7 +226,7 @@ The result should look similar to the following output::
    I: Connected to CF:2F:99:89:A3:4D (random), number of connections 14
    I: Connected to EF:92:DC:88:3B:B3 (random), number of connections 15
    I: Connected to D9:E5:51:E0:5E:24 (random), number of connections 16
-   I: 4 seconds to create 16 connections
+   I: 2 seconds to create 16 connections
    I: Disconnecting connections...
    I: ---------------------------------------------------------------------
    I: ---------------------------------------------------------------------

samples/bluetooth/scanning_while_connecting/src/main.c

@@ -437,6 +437,35 @@ int main(void)
 
 	hci_vs_sdc_central_acl_event_spacing_set(&event_spacing_params);
 
+	/** Set a small connection event length to leave more time for scanning.
+	 *
+	 * This can also be set at compile time by using the Kconfig option
+	 * CONFIG_BT_CTLR_SDC_MAX_CONN_EVENT_LEN_DEFAULT in the prj.conf file.
+	 */
+	sdc_hci_cmd_vs_event_length_set_t event_length_params = {
+		.event_length_us = 2000,
+	};
+
+	hci_vs_sdc_event_length_set(&event_length_params);
+
+	/** Connection event extension is turned on by default. This is turned on by default
+	 * to achieve higher throughput. As a consequence, the scheduler will schedule
+	 * longer connection events at the cost of scanning events. In this sample application,
+	 * we try to achieve faster connection establishment, so we turn connection
+	 * event extension off. Thus, the controller schedules more time for scanning.
+	 *
+	 * This can also be turned off at compile time by setting the Kconfig option
+	 * BT_CTLR_SDC_CONN_EVENT_EXTEND_DEFAULT=n in the prj.conf file.
+	 *
+	 * See our scheduling documentation under nrfxlib/softdevice_controller for
+	 * more information.
+	 */
+	sdc_hci_cmd_vs_conn_event_extend_t conn_event_extend_params = {
+		.enable = 0,
+	};
+
+	hci_vs_sdc_conn_event_extend(&conn_event_extend_params);
+
 	for (uint8_t i = 0; i < ARRAY_SIZE(conn_establishment_modes); i++) {
 
 		active_conn_establishment_mode = conn_establishment_modes[i];