RE: BLE Central: disconnect event received immediately after connection

Susheel Nuguru — Mon, 20 Mar 2023 13:08:05 GMT

Sorry for late reply.

[quote user="m5k8"]OK, interesting :) Any hints what can I check?[/quote]

The service discovery seems to be taking too long. Can you use a faster connection interval while you are using a service discovery so that this is done faster.

RE: BLE Central: disconnect event received immediately after connection

m5k8 — Tue, 14 Mar 2023 10:58:42 GMT

OK, I'll be back with sniffer output.

But this:

[quote userid="114275" url="~/f/nordic-q-a/97637/ble-central-disconnect-event-received-immediately-after-connection"]<debug> nrf_ble_gq: SD is currently busy. The GATT request procedure will be attempted again later. [/quote]

happens also when connection proceeds correctly:

<info> app: NRF_BLE_SCAN_EVT_CONNECTED CE:EF:AC:E9:70:D2
<info> app: BLE_GAP_EVT_CONNECTED
<info> app: Connected as a central.
<info> app: Discovering GATT database...
<debug> nrf_ble_gq: Purging request queue with id: 0
<debug> nrf_ble_gq: Registering connection handle: 0x0000
<debug> ble_db_disc: Starting discovery of service with UUID 0x3EC0 on connection handle 0x0.
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Primary Services Discovery Request
<debug> nrf_ble_gq: SD is currently busy. The GATT request procedure will be attempted again later.
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: GATTC Primary Service Discovery Request
<debug> nrf_ble_gq: SD is currently busy. The GATT request procedure will be attempted again la
ter.
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: GATTC Primary Service Discovery Request
<debug> nrf_ble_gq: SD GATT procedure (2) succeeded on connection handle: 0.
<debug> nrf_ble_gatt: ATT MTU updated to 247 bytes on connection 0x0 (response).
<debug> app: BLE_GATTC_EVT_EXCHANGE_MTU_RSP
<debug> nrf_ble_gatt: Data length updated to 251 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 251
<debug> nrf_ble_gatt: max_tx_octets: 251
<debug> nrf_ble_gatt: max_rx_time: 2120
<debug> nrf_ble_gatt: max_tx_time: 2120
<debug> app: BLE_GAP_EVT_DATA_LENGTH_UPDATE
<debug> nrf_ble_gq: Processing the request queue...
<debug> ble_db_disc: Found service UUID 0x3EC0.
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Characteristic Discovery Request
<debug> nrf_ble_gq: SD GATT procedure (3) succeeded on connection handle: 0.
<debug> app: BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Characteristic Discovery Request
<debug> nrf_ble_gq: SD GATT procedure (3) succeeded on connection handle: 0.
<debug> app: BLE_GATTC_EVT_CHAR_DISC_RSP
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Characteristic Discovery Request
<debug> nrf_ble_gq: SD GATT procedure (3) succeeded on connection handle: 0.
<debug> app: BLE_GATTC_EVT_CHAR_DISC_RSP
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Characteristic Descriptor Request
<debug> nrf_ble_gq: SD GATT procedure (4) succeeded on connection handle: 0.
<debug> app: BLE_GATTC_EVT_CHAR_DISC_RSP
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Characteristic Descriptor Request
<debug> nrf_ble_gq: SD GATT procedure (4) succeeded on connection handle: 0.
<debug> app: BLE_GATTC_EVT_DESC_DISC_RSP
<debug> nrf_ble_gq: Processing the request queue...
<debug> ble_db_disc: Discovery of service with UUID 0x3EC0 completed with success on connection handle 0x0.
<info> app: BLE_DB_DISCOVERY_COMPLETE
<info> app: BLE_DB_DISCOVERY_AVAILABLE

so I assumed it's just normal. Is it, or not?

[quote userid="6207" url="~/f/nordic-q-a/97637/ble-central-disconnect-event-received-immediately-after-connection/415106"]seems interesting on what is keeping SD busy[/quote]

OK, interesting :) Any hints what can I check?

RE: BLE Central: disconnect event received immediately after connection

Susheel Nuguru — Tue, 14 Mar 2023 10:01:20 GMT

It would really help in this case if you could attach the sniffer log from the connection to the disconnection.

This below part seems interesting on what is keeping SD busy and also to see the source of disconnection.

<debug> nrf_ble_gq: SD is currently busy. The GATT request procedure will be attempted                           again