ble_app_hrs_c example fails reconnect on SDK 15.2.0

[Jacques]

Hi,

I'm using a PCA10040 devboard to test the heart rate client example. I see that when using the example from SDK v15.2.0, I can connect to my (Polar) heart rate device, and if I reset the devboard, it will recognize the sensor and reconnect. However, if I power off the sensor, and power it back on, I get an error "PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING".

I did the same experiment using the example from the SDK v14.2.0, and that one reconnects with no issues. 

I'm not sure if this is a peer manager issue or to do with some security option.

Any ideas?

[Hung Bui]

It sounds like the Polar heart rate didn't store the bond information of the nRF52. 

If you can provide a sniffer trace we can see it more clearly. 

If you test it with a phone, do you see the same problem ? 

[Jacques]

It would be normal for the Polar to not store the bond information, wouldn't it? It is a commercial heart rate sensor after all, and has the role of peripheral. 

[Jacques]

Also, like I said, This works fine on SDK v14.2.0, with the same heart rate sensor

[Hung Bui]

Hi, 

I don't know how the Polar works particularly. If you test with the phone do you see the same problem ? 

Could you capture sniffer traces when testing with SDK v14.2 and when testing with 15.2 ? 

[Jacques]

I can't get a trace going, but here is the debug output for an initial connection to an HRS, disconnect, and (attempted) reconnect. Same dev board and sensor.

The sdk15.2.0 example returns the error "PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING" (0x4102) on the first connection (unless you erase the chip first) but still accepts heart rate notifications the first time. On reconnect, it doesn't accept notifications, regardless of whether or not you erase the chip first. Something is not working in the peer manager...

Fullscreen sdk15_2_0.txt Download

<debug> nrf_sdh: State request: 0x00000000
<debug> nrf_sdh: Notify observer 0x0003D9A0 => ready
<debug> nrf_sdh: State change: 0x00000000
<debug> nrf_sdh: State change: 0x00000001
<debug> nrf_sdh_ble: RAM starts at 0x20002AD8
<debug> ble_scan: Added filter on UUID 180D
<info> app: Heart Rate collector example started.
<info> app: Starting scan.
<debug> ble_scan: Scanning
<debug> nrf_sdh_ble: BLE event: 0x1D.
<debug> ble_scan: Connecting
<debug> ble_scan: Connection status: 0
<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
<debug> peer_manager_handler: Event PM_EVT_BONDED_PEER_CONNECTED
<debug> peer_manager_handler: Previously bonded peer connected: role: Central, conn_handle: 0, peer_id: 0
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_PARAMS_REQ
<debug> peer_manager_handler: Security parameter request
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_START
<debug> peer_manager_handler: Connection security procedure started: role: Central, conn_handle: 0, procedure: Encryption
<debug> peer_manager_handler: pm_peer_rank_highest() returned NRF_ERROR_NOT_SUPPORTED for peer id 0
<debug> peer_manager_handler: Event PM_EVT_LOCAL_DB_CACHE_APPLIED
<debug> peer_manager_handler: Previously stored local DB applied: conn_handle: 0, peer_id: 0
<info> app: Connected.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> nrf_ble_gatt: ATT MTU updated to 232 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 232.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_FAILED
<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4102
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 236 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 236
<debug> nrf_ble_gatt: max_tx_octets: 236
<debug> nrf_ble_gatt: max_rx_time: 2120
<debug> nrf_ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x23.
<debug> nrf_ble_gatt: Peer on connection 0x0 requested a data length of 236 bytes.
<debug> nrf_ble_gatt: Updating data length to 236 on connection 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 236 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 236
<debug> nrf_ble_gatt: max_tx_octets: 236
<debug> nrf_ble_gatt: max_rx_time: 2120
<debug> nrf_ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180D.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180D completed with success on connection handle 0x0.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180F on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180F.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180F completed with success on connection handle 0x0.
<debug> ble_hrs_c: Heart Rate Service discovered at peer.
<debug> app: Heart rate service discovered.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_PARAMS_REQ
<debug> peer_manager_handler: Security parameter request
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_START
<debug> peer_manager_handler: Connection security procedure started: role: Central, conn_handle: 0, procedure: Encryption
<debug> ble_hrs_c: Configuring CCCD. CCCD Handle = 38, Connection Handle = 0
<debug> ble_bas_c: Battery Service discovery failure at peer. 
<debug> ble_bas_c: Battery Service discovered at peer.
<debug> app: Battery Service discovered. Reading battery level.
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> app: Enabling Battery Level Notification.
<debug> ble_bas_c: Configuring CCCD. CCCD Handle = 42, Connection Handle = 0
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_FAILED
<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4102
<debug> nrf_sdh_ble: BLE event: 0x36.
<info> app: Battery Level Read as 70 %.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> nrf_sdh_ble: BLE event: 0x36.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x11.
<info> app: Disconnected, reason 0x13.
<info> app: Starting scan.
<debug> ble_scan: Scanning
<debug> nrf_sdh_ble: BLE event: 0x1D.
<debug> ble_scan: Connecting
<debug> ble_scan: Connection status: 0
<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
<debug> peer_manager_handler: Event PM_EVT_BONDED_PEER_CONNECTED
<debug> peer_manager_handler: Previously bonded peer connected: role: Central, conn_handle: 0, peer_id: 0
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_PARAMS_REQ
<debug> peer_manager_handler: Security parameter request
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_START
<debug> peer_manager_handler: Connection security procedure started: role: Central, conn_handle: 0, procedure: Encryption
<debug> peer_manager_handler: pm_peer_rank_highest() returned NRF_ERROR_NOT_SUPPORTED for peer id 0
<debug> peer_manager_handler: Event PM_EVT_LOCAL_DB_CACHE_APPLIED
<debug> peer_manager_handler: Previously stored local DB applied: conn_handle: 0, peer_id: 0
<info> app: Connected.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x11.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_FAILED
<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4352
<info> app: Disconnected, reason 0x3E.
<info> app: Starting scan.
<debug> ble_scan: Scanning
<debug> nrf_sdh_ble: BLE event: 0x1D.
<debug> ble_scan: Connecting
<debug> ble_scan: Connection status: 0
<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
<debug> peer_manager_handler: Event PM_EVT_BONDED_PEER_CONNECTED
<debug> peer_manager_handler: Previously bonded peer connected: role: Central, conn_handle: 0, peer_id: 0
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_PARAMS_REQ
<debug> peer_manager_handler: Security parameter request
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_START
<debug> peer_manager_handler: Connection security procedure started: role: Central, conn_handle: 0, procedure: Encryption
<debug> peer_manager_handler: pm_peer_rank_highest() returned NRF_ERROR_NOT_SUPPORTED for peer id 0
<debug> peer_manager_handler: Event PM_EVT_LOCAL_DB_CACHE_APPLIED
<debug> peer_manager_handler: Previously stored local DB applied: conn_handle: 0, peer_id: 0
<info> app: Connected.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> nrf_ble_gatt: ATT MTU updated to 232 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 232.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_FAILED
<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4102
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 236 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 236
<debug> nrf_ble_gatt: max_tx_octets: 236
<debug> nrf_ble_gatt: max_rx_time: 2120
<debug> nrf_ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x23.
<debug> nrf_ble_gatt: Peer on connection 0x0 requested a data length of 236 bytes.
<debug> nrf_ble_gatt: Updating data length to 236 on connection 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 236 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 236
<debug> nrf_ble_gatt: max_tx_octets: 236
<debug> nrf_ble_gatt: max_rx_time: 2120
<debug> nrf_ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180D.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180D completed with success on connection handle 0x0.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180F on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180F.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180F completed with success on connection handle 0x0.
<debug> ble_hrs_c: Heart Rate Service discovered at peer.
<debug> app: Heart rate service discovered.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_PARAMS_REQ
<debug> peer_manager_handler: Security parameter request
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_START
<debug> peer_manager_handler: Connection security procedure started: role: Central, conn_handle: 0, procedure: Encryption
<debug> ble_hrs_c: Configuring CCCD. CCCD Handle = 38, Connection Handle = 0
<debug> ble_bas_c: Battery Service discovery failure at peer. 
<debug> ble_bas_c: Battery Service discovered at peer.
<debug> app: Battery Service discovered. Reading battery level.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> app: Enabling Battery Level Notification.
<debug> ble_bas_c: Configuring CCCD. CCCD Handle = 42, Connection Handle = 0
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> nrf_sdh_ble: BLE event: 0x36.
<info> app: Battery Level Read as 60 %.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> peer_manager_handler: Event PM_EVT_CONN_SEC_FAILED
<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4102
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> nrf_sdh_ble: BLE event: 0x36.

Fullscreen sdk14_2_0.txt Download

<debug> nrf_sdh: State request: 0x00000000
<debug> nrf_sdh: Notify observer 0x00036434 => ready
<debug> nrf_sdh: State change: 0x00000000
<debug> nrf_sdh: State change: 0x00000001
<debug> nrf_sdh_ble: RAM starts at 0x200029A0
<info> app: Heart Rate collector example started.
<info> app: Starting scan.
<debug> nrf_sdh_ble: BLE event: 0x1D.
<info> app: UUID match send connect_request.
<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> ble_gatt: Requesting to update data length to 251 on connection 0x0.
<info> app: Connected to a previously bonded device.
<info> app: Connected.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> ble_gatt: ATT MTU updated to 232 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 232.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> ble_gatt: Data length updated to 236 on connection 0x0.
<debug> ble_gatt: max_rx_octets: 236
<debug> ble_gatt: max_tx_octets: 236
<debug> ble_gatt: max_rx_time: 2120
<debug> ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180D.
<debug> nrf_sdh_ble: BLE event: 0x23.
<debug> ble_gatt: Peer on connection 0x0 requested a data length of 236 bytes.
<debug> ble_gatt: Updating data length to 236 bytes on connection 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> ble_gatt: Data length updated to 236 on connection 0x0.
<debug> ble_gatt: max_rx_octets: 236
<debug> ble_gatt: max_tx_octets: 236
<debug> ble_gatt: max_rx_time: 2120
<debug> ble_gatt: max_tx_time: 2000
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180D completed with success on connection handle 0x0.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180F on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180F.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180F completed with success on connection handle 0x0.
<debug> ble_hrs_c: Heart Rate Service discovered at peer.
<debug> app: Heart rate service discovered.
<debug> ble_hrs_c: Configuring CCCD. CCCD Handle = 38, Connection Handle = 0
<debug> ble_bas_c: Battery Service discovery failure at peer. 
<debug> ble_bas_c: Battery Service discovered at peer.
<debug> app: Battery Service discovered. Reading battery level.
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> app: Enabling Battery Level Notification.
<debug> ble_bas_c: Configuring CCCD. CCCD Handle = 42, Connection Handle = 0
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<info> app: Connection secured: role: 2, conn_handle: 0x0, procedure: 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x36.
<info> app: Battery Level Read as 60 %.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<info> app: Connection secured: role: 2, conn_handle: 0x0, procedure: 0.
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 92.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 92.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 92.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x11.
<info> app: Disconnected, reason 0x13.
<info> app: Starting scan.
<debug> nrf_sdh_ble: BLE event: 0x1D.
<info> app: UUID match send connect_request.
<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> ble_gatt: Requesting to update data length to 251 on connection 0x0.
<info> app: Connected to a previously bonded device.
<info> app: Connected.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> ble_gatt: ATT MTU updated to 232 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 232.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180D on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> ble_gatt: Data length updated to 236 on connection 0x0.
<debug> ble_gatt: max_rx_octets: 236
<debug> ble_gatt: max_tx_octets: 236
<debug> ble_gatt: max_rx_time: 2120
<debug> ble_gatt: max_tx_time: 2120
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x23.
<debug> ble_gatt: Peer on connection 0x0 requested a data length of 236 bytes.
<debug> ble_gatt: Updating data length to 236 bytes on connection 0x0.
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> ble_gatt: Data length updated to 236 on connection 0x0.
<debug> ble_gatt: max_rx_octets: 236
<debug> ble_gatt: max_tx_octets: 236
<debug> ble_gatt: max_rx_time: 2120
<debug> ble_gatt: max_tx_time: 2000
<info> app: Data length for connection 0x0 updated to 236.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180D.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180D completed with success on connection handle 0x0.
<debug> ble_db_disc: Starting discovery of service with UUID 0x180F on connection handle 0x0.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0x180F.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x32.
<debug> nrf_sdh_ble: BLE event: 0x33.
<debug> ble_db_disc: Discovery of service with UUID 0x180F completed with success on connection handle 0x0.
<debug> ble_hrs_c: Heart Rate Service discovered at peer.
<debug> app: Heart rate service discovered.
<debug> ble_hrs_c: Configuring CCCD. CCCD Handle = 38, Connection Handle = 0
<debug> ble_bas_c: Battery Service discovery failure at peer. 
<debug> ble_bas_c: Battery Service discovered at peer.
<debug> app: Battery Service discovered. Reading battery level.
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> app: Enabling Battery Level Notification.
<debug> ble_bas_c: Configuring CCCD. CCCD Handle = 42, Connection Handle = 0
<debug> ble_bas_c: SD Read/Write API returns error. This message sending will be attempted again..
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x36.
<info> app: Battery Level Read as 60 %.
<debug> ble_bas_c: SD Read/Write API returns Success..
<debug> nrf_sdh_ble: BLE event: 0x1A.
<debug> nrf_sdh_ble: BLE event: 0x38.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.
<debug> nrf_sdh_ble: BLE event: 0x39.
<debug> ble_hrs_c: Received HVX on link 0x25, hrm_handle 0x25
<info> app: Heart Rate = 0.