How to add custom service to the Ble_app_template example

[sagarnayakm]

Hello i am using nrf52810 with SDK version 17.0.2 , i want to add custom service to the ble_app_template example and i followed this tutorial link https://github.com/edvinand/custom_ble_service_example so at first debug i got this error as expected 

next i have change the RAM_START AND RAM_SIZE as per the memory size mentioned in the error then i DEBUG it again so the i got 

so i don't know what's happening please help me to resolve this . 

thank you.

[Karl Ylvisaker]

Hello again,

sagarnayakm said:

so i don't know i am blanked what to do i tried so many times if i comment the  p_cus_init->evt_handler == NULL in ble_cus_init() function then it starts advertising. so please help me to resolve this.

But this does not solve the underlying issue, it is just treating the symptoms. If you just remove error checks that fail the errors will still be there, you just will not know about it.
To fix it, and make it function as expected you will need to resolve the underlying issue.

sagarnayakm said:

i got issue like the p_cus_init->evt_handler == NULL in ble_cus_init() function after this its not executing

Have you implemented and provided an event handler for your custom service during its initialization?

Best regards,
Karl

[sagarnayakm]

Karl Ylvisaker said:

Have you implemented and provided an event handler for your custom service during its initialization?

Yes, in service init() i have declare like this,

.

static void services_init(void)
{
    ret_code_t         err_code;
    
    nrf_ble_qwr_init_t qwr_init = {0};
    ble_cus_init_t                     cus_init;
    
    

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;


     cus_init.evt_handler               = on_cus_evt;
   

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
    APP_ERROR_CHECK(err_code);

    /* YOUR_JOB: Add code to initialize the services used by the application.
       ble_xxs_init_t                     xxs_init;
       ble_yys_init_t                     yys_init;

       // Initialize XXX Service.
       memset(&xxs_init, 0, sizeof(xxs_init));

       xxs_init.evt_handler                = NULL;
       xxs_init.is_xxx_notify_supported    = true;
       xxs_init.ble_xx_initial_value.level = 100;

       err_code = ble_bas_init(&m_xxs, &xxs_init);
       APP_ERROR_CHECK(err_code);

       // Initialize YYY Service.
       memset(&yys_init, 0, sizeof(yys_init));
       yys_init.evt_handler                  = on_yys_evt;
       yys_init.ble_yy_initial_value.counter = 0;

       err_code = ble_yy_service_init(&yys_init, &yy_init);
       APP_ERROR_CHECK(err_code);
     */

    
    
    // Initialize CUS Service.
    memset(&cus_init, 0, sizeof(cus_init));
    
    err_code = ble_cus_init(&m_cus, &cus_init);
    printf("err_code:%d",err_code);
    APP_ERROR_CHECK(err_code);   
 
    
    
}

and handler is,

 

static void on_cus_evt(ble_cus_t     * p_cus_service,
                       ble_cus_evt_t * p_evt)
{
 
    switch(p_evt->evt_type)
    {
        case BLE_CUS_EVT_CONNECTED:
            break;

        case BLE_CUS_EVT_DISCONNECTED:
            break;

        default:
            // No implementation needed.
            break;
    }

}

in tutorial i got that the handler should not be NULL so how can achieve this.??

[Karl Ylvisaker]

It looks to me like you do not set the event handler as part of the ble_cus_init function in the function you shared previously. It seems you have omitted the line where the provided handler is registered to the custom service.
Please rectify this, and let me know if this resolves your issue.

Best regards,
Karl

[sagarnayakm]

Hello, 

No, i added but from that only problem created right..?? so removed. the updated ble_cus_init() function is 

ret_code_t ble_cus_init(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
{
    NRF_LOG_INFO("i am cu_init\r\n");
    if (p_cus == NULL || p_cus_init == NULL || p_cus_init->evt_handler == NULL)
    {
        return NRF_ERROR_NULL;
    }

    ret_code_t  err_code;
    ble_uuid_t  ble_uuid;

    // Initialize service structure
    p_cus->evt_handler               = p_cus_init->evt_handler;
    p_cus->conn_handle               = BLE_CONN_HANDLE_INVALID;

    // Add Custom Service UUID
    ble_uuid128_t base_uuid = {CUSTOM_SERVICE_UUID_BASE};
    err_code =  sd_ble_uuid_vs_add(&base_uuid, &p_cus->uuid_type);
    VERIFY_SUCCESS(err_code);
    
    ble_uuid.type = p_cus->uuid_type;
    ble_uuid.uuid = CUSTOM_SERVICE_UUID;

     
    // Add the Custom Service
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_cus->service_handle);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;    // This seems redundant, but we'll add more later
    }
    
  // Add the Custom Value Characteristic
    return custom_value_char_add(p_cus, p_cus_init);
    
}

but still same result and in service _init() if i comment memset of cus_init() then  advertising happened and i wrote two lines to receive the data which i have sent is it correct because whatever  the data if i sent same number was received.

Karl Ylvisaker said:

But this does not solve the underlying issue, it is just treating the symptoms. If you just remove error checks that fail the errors will still be there, you just will not know about it.
To fix it, and make it function as expected you will need to resolve the underlying issue.

so i have correct this that is my bad i added extra return this issue is resolved 

please let me if there is any mistake.

thank you.

[sagarnayakm]

this is two lines i have added to receive the data from mobile app 

static void on_write(ble_cus_t * p_cus, ble_evt_t const * p_ble_evt)
{
    ble_gatts_evt_write_t * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
    p_evt_write->data[0]=p_evt_write;
    printf("%d", p_evt_write->data[0]);
    // Check if the handle passed with the event matches the Custom Value Characteristic handle.
    if (p_evt_write->handle == p_cus->custom_value_handles.value_handle)
    {
        nrf_gpio_pin_toggle(LED_4); 
    }
}