nRF Connect log

RE: nRF Connect log

Karthiknk — Tue, 02 Feb 2021 22:35:42 GMT

Thank you for your support. I got the values.

RE: nRF Connect log

Karthiknk — Tue, 02 Feb 2021 22:20:15 GMT

Sorry I was wrong. Service discovery was not complete. I do not receive the (Discovery of service with UUID 0xABCD completed with success on connection handle 0x0) message. The RTT stops at the following message.

[quote userid="95071" url="~/f/nordic-q-a/70659/nrf-connect-log/292090#292090"]<debug> nrf_sdh_ble: BLE event: 0x32.
<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> nrf_ble_gq: Processing the request queue...[/quote]

I think BLE_C_EVT_DISCOVERY_COMPLETE event is not updated. RTT says GATT procedure 4 succeeded, then the debugger stops running.

RE: nRF Connect log

Simonr — Tue, 02 Feb 2021 08:16:06 GMT

How do you handle the service once the devices are connected and the service is discovered? What do you do in your central application to read the service values?

As you can see in the ble_app_hrs_c example in our SDK, the Heart Rate Collector handler enables notifications of the heart rate service after service discovery in order to get the Heart Rate values periodically.

Best regards,

Simon

RE: nRF Connect log

Karthiknk — Mon, 01 Feb 2021 14:10:50 GMT

[quote userid="75734" url="~/f/nordic-q-a/70659/nrf-connect-log/292164#292164"]So you're still seeing the values read from the peripheral device in hexadecimal values, correct?[/quote]

No, I can not see the value from the peripheral. I have shared the debugger log above. As you can see there are no values in the log.

RE: nRF Connect log

Simonr — Mon, 01 Feb 2021 09:59:34 GMT

Glad you got the connection and service discovery working correctly! So you're still seeing the values read from the peripheral device in hexadecimal values, correct? You still need to process the data received and output it in a readable way.

Best regards,

Simon

RE: nRF Connect log

Karthiknk — Sun, 31 Jan 2021 22:06:20 GMT

Problem fixed. The service declaration in central and peripheral were bit different, I changed it. Now it can connects and identify the service.

<info> app: Connected.
<debug> nrf_ble_gq: Registering connection handle: 0x0000
<debug> ble_db_disc: Starting discovery of service with UUID 0xABCD 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 later.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> nrf_ble_gatt: ATT MTU updated to 23 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 23.
<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_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 27 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 27
<debug> nrf_ble_gatt: max_tx_octets: 27
<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 27.
<debug> nrf_sdh_ble: BLE event: 0x30.
<debug> ble_db_disc: Found service UUID 0xABCD.
<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> nrf_ble_gq: Processing the request queue...
<debug> nrf_sdh_ble: BLE event: 0x32.
<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> nrf_ble_gq: Processing the request queue...
<debug> nrf_sdh_ble: BLE event: 0x32.
<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> nrf_ble_gq: Processing the request queue...

But still, I can not see the data. Can you suggest what could possibly be the problem?

RE: nRF Connect log

Karthiknk — Sun, 31 Jan 2021 19:12:31 GMT

[quote userid="95071" url="~/f/nordic-q-a/70659/nrf-connect-log/291146#291146"]<debug> ble_db_disc: Starting discovery of service with UUID 0xABCD on connection handle 0x0[/quote]

From my error message, I can see the central is looking for service with UUID 0xABCD. Also to make sure, my peripheral is also advertising 128-bit base UUID with service ABCE in it.

I don't understand what is creating the error.

[quote userid="95071" url="~/f/nordic-q-a/70659/nrf-connect-log/291146#291146"]<error> nrf_ble_gq: SD GATT procedure (2) failed on connection handle 0 with error: 0x00000007.[/quote]

RE: nRF Connect log

Karthiknk — Sun, 31 Jan 2021 18:53:28 GMT

Yes, I did.

static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
ble_acl_on_db_disc_evt(&m_acl_c, p_evt);
}

I followed this tutorial How to build the simple nrf52 BLE central. I will attach the code blocks of service initialisation and database discovery event below, please check them.

uint32_t ble_acl_c_init(ble_acl_c_t * p_ble_acl_c, ble_acl_c_init_t * p_ble_acl_c_init)
{
    VERIFY_PARAM_NOT_NULL(p_ble_acl_c);
    VERIFY_PARAM_NOT_NULL(p_ble_acl_c_init);
    VERIFY_PARAM_NOT_NULL(p_ble_acl_c_init->evt_handler);

    uint32_t      err_code;
    ble_uuid_t    acl_uuid;
    ble_uuid128_t acl_service_base_uuid = {BLE_UUID_OUR_BASE_UUID};

    acl_uuid.type = p_ble_acl_c->uuid_type;
    acl_uuid.uuid = BLE_UUID_OUR_SERVICE;

    p_ble_acl_c->evt_handler                 = p_ble_acl_c_init->evt_handler;
    p_ble_acl_c->error_handler               = p_ble_acl_c_init->error_handler;
    p_ble_acl_c->p_gatt_queue                = p_ble_acl_c_init->p_gatt_queue;
    p_ble_acl_c->conn_handle                 = BLE_CONN_HANDLE_INVALID;
    p_ble_acl_c->peer_acl_db.acl_cccd_handle = BLE_GATT_HANDLE_INVALID;
    p_ble_acl_c->peer_acl_db.acl_handle      = BLE_GATT_HANDLE_INVALID;

    err_code = sd_ble_uuid_vs_add(&acl_service_base_uuid, &p_ble_acl_c->uuid_type);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }
    VERIFY_SUCCESS(err_code);
    
    return ble_db_discovery_evt_register(&acl_uuid);
}

void ble_acl_on_db_disc_evt(ble_acl_c_t * p_ble_acl_c, const ble_db_discovery_evt_t * p_evt)
{
    // Check if the Heart Rate Service was discovered.
    if (p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE &&
        p_evt->params.discovered_db.srv_uuid.uuid == BLE_UUID_OUR_SERVICE &&
        p_evt->params.discovered_db.srv_uuid.type == p_ble_acl_c->uuid_type)
    {
        // Find the CCCD Handle of the Heart Rate Measurement characteristic.
        uint32_t i;

        ble_acl_c_evt_t evt;

        evt.evt_type    = BLE_ACL_C_EVT_DISCOVERY_COMPLETE;
        evt.conn_handle = p_evt->conn_handle;


        for (uint32_t i = 0; i < p_evt->params.discovered_db.char_count; i++)
        {
            const ble_gatt_db_char_t * p_char = &(p_evt->params.discovered_db.charateristics[i]);
            switch (p_char->characteristic.uuid.uuid)
            {
                case BLE_UUID_OUR_CHARACTERISTC_UUID:
                    evt.params.peer_db.acl_cccd_handle = p_char->cccd_handle;
                    evt.params.peer_db.acl_handle      = p_char->characteristic.handle_value;
                    break;
                default:
                    break;
            }
        }

        NRF_LOG_DEBUG("Accelerometer Service discovered at peer.");
        //If the instance has been assigned prior to db_discovery, assign the db_handles.
        if (p_ble_acl_c->conn_handle != BLE_CONN_HANDLE_INVALID)
        {
            if (p_ble_acl_c->peer_acl_db.acl_handle == BLE_GATT_HANDLE_INVALID)
            {
                p_ble_acl_c->peer_acl_db = evt.params.peer_db;
            }
        }

        p_ble_acl_c->evt_handler(p_ble_acl_c, &evt);
    }
}

If you need additional details, I can give you. And one more question, while programming our own service in peripheral, we mention the UUID is vendor-specific using BLE_UUID_TYPE_VENDOR_BEGIN, but in central, the tutorial didn't mention it anywhere. I doubt if that could be the problem.

Thank you.

RE: nRF Connect log

Simonr — Tue, 26 Jan 2021 08:34:44 GMT

The error code 0x07 points towards you using an invalid parameter in you GATT request. Have you edited the db_disc_handler to handler custom service discoveries rather than the heart rate and battery services used by default?

Best regards,

Simon

RE: nRF Connect log

Karthiknk — Mon, 25 Jan 2021 22:13:29 GMT

Thank you for the reference. I have gone through most of the materials already. Like I said before, I have successfully created my own service and I can get data in nRF connect application. Now I'm trying to create central program for my service, so I can implement relay with my service. I took the heart rate measurement central program and did some modulations. When I try to connect my central and peripheral, I get the following in the RTT.

<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.
<info> app: Connected.
<debug> nrf_ble_gq: Registering connection handle: 0x0000
<debug> ble_db_disc: Starting discovery of service with UUID 0xABCD on connection handle 0x0.
<debug> nrf_ble_gq: Adding item to the request queue
<debug> nrf_ble_gq: GATTC Primary Services Discovery Request
<error> nrf_ble_gq: SD GATT procedure (2) failed on connection handle 0 with error: 0x00000007.
<debug> ble_bas_c: Battery Service discovery failure at peer.
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> nrf_ble_gatt: ATT MTU updated to 23 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 23.
<debug> nrf_ble_gq: Processing the request queue...
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 27 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 27
<debug> nrf_ble_gatt: max_tx_octets: 27
<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 27.
<debug> nrf_sdh_ble: BLE event: 0x1F.
<debug> nrf_sdh_ble: BLE event: 0x12.

"<error> nrf_ble_gq: SD GATT procedure (2) failed on connection handle 0 with error: 0x00000007." I don't understand this. What could be the problem.

On ble_app_hrs_c_pca I just changed the base, service and characteristic UUID from hrm to my own service.

RE: nRF Connect log

Simonr — Fri, 22 Jan 2021 06:35:05 GMT

It does not seem like there is a "standard accelerometer service", but there are quite a few examples out there already. Please check out the following cases for reference: custom BLE service tutorial, adding accelerometer data to your own service, BLE accelerometer service stackoverflow.

Best regards,

Simon

RE: nRF Connect log

Karthiknk — Wed, 20 Jan 2021 18:47:19 GMT

I'm using a custom accelerometer service. I followed Bluetooth low energy characteristics, a beginner's tutorial. If there is a standard accelerometer service, I would like to know about it. In that case, there if there a standard accelerometer client, that can decode my data easily. Because, I'm trying to program my custom accelerometer client, and it is quite difficult. In the end, I want to implement this accelerometer service into a relay network. So, if you have a standard accelerometer service or client or any related programs and tutorials, that would be very helpful. Thank you.

RE: nRF Connect log

Simonr — Wed, 20 Jan 2021 10:36:16 GMT

The nRFConnect app uses the Heart Rate Measurement profile in BLE in order to decode the Heart Rate measurement values from the peripheral that uses the Heart Rate Service. I believe the Android central app uses a similar procedure as the Heart Rate Service Client module in our SDK.

So, are you using a standard accelerometer service in your peripheral application, or are you using a custom service on your end? If so, you would need a custom client as well that knows how to decode and output these hexadecimal values correctly.

Best regards,

Simon