getting service count from database discovery module

[goldwake]

I'm currently trying to use the database discovery module to get the total number of services and the number of discovered services so that I know when all of the services for a particular peripheral device are discovered and set up before discovering the next device. I'm doing this because from what I've found, you can't do things like sd_ble_gattc_write while a discovery is in progress.

The issue is that the srv_count and discoveries_count fields in ble_db_discovery_t don't seem to be updated correctly. The srv_count field is always zero, in fact I don't see it referenced anywhere but where it is defined in ble_db_discovery.h, and discoveries_count seems to be one less than the number of services registered using ble_db_discovery_evt_register

Am I missing something? Is there another way I can check if all the services have been discovered?

The services field is updated so I can iterate through that array to get total number of services and manually keep track of discoveries using the BLE_DB_DISCOVERY_COMPLETE event but, it would be nice to get my code working with the database discovery module

I'm using SDK v12.1 with a NRF52

EDIT 13 April 17

To add to this, the BLE_DB_DISCOVERY_AVAILABLE event is never triggered in db_discovery. I've fixed it as shown below. It's not thoroughy tested but, works so far. I've added it because the BLE_DB_DISCOVERY_COMPLETE event is generated before discovery_in_progress is set to false so, when i receive BLE_DB_DISCOVERY_AVAILABLE, i can start discovery of the next pending connection

diff --git a/v12.1/ble/ble_db_discovery/ble_db_discovery.c b/v12.1/ble/ble_db_discovery/ble_db_discovery.c
index ab9e98d..df43c0c 100644
--- a/v12.1/ble/ble_db_discovery/ble_db_discovery.c
+++ b/v12.1/ble/ble_db_discovery/ble_db_discovery.c
@@ -146,6 +146,27 @@ static void discovery_error_evt_trigger(ble_db_discovery_t * const p_db_discover
     }
 }
 
+static void discovery_available_evt_trigger(ble_db_discovery_t * const p_db_discovery,
+                                        uint32_t                   err_code,
+                                        uint16_t const             conn_handle)
+{
+    ble_db_discovery_evt_handler_t p_evt_handler;
+    ble_gatt_db_srv_t            * p_srv_being_discovered;
+
+    p_srv_being_discovered = &(p_db_discovery->services[p_db_discovery->curr_srv_ind]);
+
+    p_evt_handler = registered_handler_get(&(p_srv_being_discovered->srv_uuid));
+
+    if (p_evt_handler != NULL)
+    {
+        ble_db_discovery_evt_t evt;
+
+        evt.conn_handle     = conn_handle;
+        evt.evt_type        = BLE_DB_DISCOVERY_AVAILABLE;
+        p_evt_handler(&evt);
+    }
+}
+
 
 /**@brief     Function for triggering a Discovery Complete or Service Not Found event to the
  *            application.
@@ -258,9 +279,11 @@ static void on_srv_disc_completion(ble_db_discovery_t * p_db_discovery,
             // Error with discovering the service.
             // Indicate the error to the registered user application.
             discovery_error_evt_trigger(p_db_discovery, err_code, conn_handle);
+            
+            discovery_available_evt_trigger(p_db_discovery, false, conn_handle);
 
-            m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-            m_pending_user_evts[0].evt.conn_handle = conn_handle;
+            //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+            //m_pending_user_evts[0].evt.conn_handle = conn_handle;
 //            m_evt_handler(&m_pending_user_evts[0].evt);
 
             return;
@@ -270,8 +293,9 @@ static void on_srv_disc_completion(ble_db_discovery_t * p_db_discovery,
     {
         // No more service discovery is needed.
         p_db_discovery->discovery_in_progress  = false;
-        m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-        m_pending_user_evts[0].evt.conn_handle = conn_handle;
+        //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+        //m_pending_user_evts[0].evt.conn_handle = conn_handle;
+        discovery_available_evt_trigger(p_db_discovery, false, conn_handle);
         //m_evt_handler(&m_pending_user_evts[0].evt);
     }
 }
@@ -552,8 +576,9 @@ static void on_primary_srv_discovery_rsp(ble_db_discovery_t * const    p_db_disc
                                         err_code,
                                         p_ble_gattc_evt->conn_handle);
 
-            m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-            m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
+            discovery_available_evt_trigger(p_db_discovery, false, p_ble_gattc_evt->conn_handle);
+            //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+            //m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
             //m_evt_handler(&m_pending_user_evts[0].evt);
         }
     }
@@ -657,8 +682,9 @@ static void on_characteristic_discovery_rsp(ble_db_discovery_t * const    p_db_d
                                             err_code,
                                             p_ble_gattc_evt->conn_handle);
 
-                m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-                m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
+                discovery_available_evt_trigger(p_db_discovery, false, p_ble_gattc_evt->conn_handle);
+                //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+                //m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
                 //m_evt_handler(&m_pending_user_evts[0].evt);
 
                 return;
@@ -690,8 +716,9 @@ static void on_characteristic_discovery_rsp(ble_db_discovery_t * const    p_db_d
                                         err_code,
                                         p_ble_gattc_evt->conn_handle);
 
-            m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-            m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
+            discovery_available_evt_trigger(p_db_discovery, false, p_ble_gattc_evt->conn_handle);
+            //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+            //m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
             //m_evt_handler(&m_pending_user_evts[0].evt);
 
             return;
@@ -790,8 +817,9 @@ static void on_descriptor_discovery_rsp(ble_db_discovery_t * const    p_db_disco
                                         err_code,
                                         p_ble_gattc_evt->conn_handle);
 
-            m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
-            m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
+            discovery_available_evt_trigger(p_db_discovery, false, p_ble_gattc_evt->conn_handle);
+            //m_pending_user_evts[0].evt.evt_type    = BLE_DB_DISCOVERY_AVAILABLE;
+            //m_pending_user_evts[0].evt.conn_handle = p_ble_gattc_evt->conn_handle;
 
             return;
         }

[run_ar]

It looks like the best solution is to iterate through that (Service field) array to get total number of services and manually keep track of discoveries using the BLE_DB_DISCOVERY_COMPLETE event as you suggested. I'll add this as a suggested improvement internally.

[goldwake]

Thanks, I'll keep an eye on the release notes for new SDKs

[run_ar]

Thanks for the update.

[goldwake]

It's been over a year that this issue has been reported and it's consistently in the Known issues lists for SDKs. Will this ever be fixed?  I'm not using  srv_count anymore but the BLE_DB_DISCOVERY_AVAILABLE  still never fires.

[run_ar]

Thank you for your feedback. The original issue was closed as fixed, not sure why it's not updated in the known issues list so I reopened the internal issue and added the updated information from you. Which SDK are you using now?