samples: bluetooth: central_hr: Fix scanning

Fix scanning so that we always use active scanning in case the UUID we
are looking for is in the scan response, and disable duplicate filtering
to handle devices that modify their advertising data at runtime, such as
smartphones reacting to apps being opened and closed.

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

samples/bluetooth/central_hr/src/main.c

@@ -180,6 +180,20 @@ static void device_found(const bt_addr_le_t *addr, s8_t rssi, u8_t type,
 	}
 }
 
+static int scan_start(void)
+{
+	/* Use active scanning and disable duplicate filtering to handle any
+	 * devices that might update their advertising data at runtime. */
+	struct bt_le_scan_param scan_param = {
+		.type       = BT_HCI_LE_SCAN_ACTIVE,
+		.filter_dup = BT_HCI_LE_SCAN_FILTER_DUP_DISABLE,
+		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
+		.window     = BT_GAP_SCAN_FAST_WINDOW,
+	};
+
+	return bt_le_scan_start(&scan_param, device_found);
+}
+
 static void disconnected(struct bt_conn *conn, u8_t reason)
 {
 	char addr[BT_ADDR_LE_STR_LEN];
@@ -196,8 +210,7 @@ static void disconnected(struct bt_conn *conn, u8_t reason)
 	bt_conn_unref(default_conn);
 	default_conn = NULL;
 
-	/* This demo doesn't require active scan */
-	err = bt_le_scan_start(BT_LE_SCAN_PASSIVE, device_found);
+	err = scan_start();
 	if (err) {
 		printk("Scanning failed to start (err %d)\n", err);
 	}
@@ -222,7 +235,7 @@ void main(void)
 
 	bt_conn_cb_register(&conn_callbacks);
 
-	err = bt_le_scan_start(BT_LE_SCAN_ACTIVE, device_found);
+	err = scan_start();
 
 	if (err) {
 		printk("Scanning failed to start (err %d)\n", err);