nRF52840 with SDK 15.2 running with BLE and Data Length Extension

[SebastianGutzwiller]

Hi all,

I observe a connection supervision timeout (HMI error code 0x08) in my Nordic firmware with certain Android smartphones (controller).

Additional info regarding GATT events: After the last connection parameter update and some GATT events the softdevice stops reporting BLE_GATTS_EVT_HVN_TX_COMPLETE and BLE_GATTS_EVT_WRITE.

After exchanging the MTU request in GATT the controller sends data length update requests over GAP with

• Max number of payload octets to receive of  251 bytes
• Max reception time of 2120 us
• Max number of payload octets to transmit of  135 bytes
• Max transmission time of 1192 us (BAD CASE) and 2120 us (GOOD CASE)

Any ideas?

[SebastianGutzwiller]

/cfs-file/__key/communityserver-discussions-components-files/4/ndk_5F00_s7_5F00_disc_5F00_dur_5F00_login2_5F00_filt.pcapng

Here is a Wireshark trace first of a good case & a bad case.

HTH Sebastian

[SebastianGutzwiller]

1) Open point: We need to check what Bluetooth event can be traced on those Android smartphones.

2) The trace was recorded with a firmware containing S140 v.6.1.1.

[SebastianGutzwiller]

After several tries with 'nRF Connect' no supervision timeout happened, see one example with BLE_HCI_LOCAL_HOST_TERMINATED_CONNECTION in ndk_s7_nrf_connect.pcapng

[Amanda Hsieh]

Could you kindly provide the completed nRF Connect log while it behaves as the first example in ndk_s7_nrf_connect.pcapng? We need the detail in the nRF Connect log. Thanks. 

-Amanda H.

[SebastianGutzwiller]

/cfs-file/__key/communityserver-discussions-components-files/4/ndk_5F00_s7_5F00_nrf_5F00_connect.pcapng

[SebastianGutzwiller]

/cfs-file/__key/communityserver-discussions-components-files/4/nrf-Connect-Log-1.txt

[Amanda Hsieh]

Hi, 

It seems like the nRF terminated the connection. Maybe you can check if you are calling sd_ble_gap_disconnect() in the function on_conn_params_evt(). 

If you are calling sd_ble_gap_disconnect(), you will see 0x16 (BLE_HCI_LOCAL_HOST_TERMINATED_CONNECTION) as disconnect reason on nRF side. Disconnect reason can be printed on the nRF side in ble_evt_handler() like this, snippet:

case BLE_GAP_EVT_DISCONNECTED:
NRF_LOG_INFO("Disconnected reason: 0x%x",p_ble_evt->evt.gap_evt.params.disconnected.reason)

-Amanda H.

[SebastianGutzwiller]

We are logging calls of sd_ble_gap_disconnect(). In our traces I don't see any calls to it.

We don't have any code containing on_conn_params_evt().

The reason for disconnect on nRF side has been integrated long time ago, see initial description.

Is there a BLE with DLE project from Nordic which I can use for further tests?

[Amanda Hsieh]

Hi,

SebastianGutzwiller said:

Is there a BLE with DLE project from Nordic which I can use for further tests?

Yes, please see ATT_MTU Throughput Example.

-Amanda H. 

[SebastianGutzwiller]

Can I connect to it with a Smartphone app to see if that connection supervision timeout is happening?

[SebastianGutzwiller]

Obviously no.

[Amanda Hsieh]

Hi, 

Sorry for the mistake. I forgot you want to test with the mobile phone.

You could try the Heart Rate Application example.

-Amanda H.