How to discover custom service of peripheral

RE: How to discover custom service of peripheral

mjr — Tue, 22 Dec 2020 10:01:16 GMT

Defined as "ble_nus_c_evt_handler"

static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
{
    ret_code_t err_code;

    switch (p_ble_nus_evt->evt_type)
    {
         
        case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
            printf("Discovery complete.");
            err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
            APP_ERROR_CHECK(err_code);

            err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
            APP_ERROR_CHECK(err_code);
            printf("Connected to device with Nordic UART Service.");
            break;

        case BLE_NUS_C_EVT_NUS_TX_EVT:
            ble_nus_chars_received_uart_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
            printf("BLE_NUS_C_EVT_NUS_TX_EVT\n");
            break;

        case BLE_NUS_C_EVT_DISCONNECTED:
            printf("Disconnected.");
            scan_start();
            break;
        default:
            printf("client evt handler\r");
            break;
    }
}

"nus_c_evt_handler" is used in "nus_c_init".

static void nus_c_init(void)
{
    ret_code_t       err_code;
    ble_nus_c_init_t init;

    memset(&init, 0, sizeof(init));

    init.evt_handler   = ble_nus_c_evt_handler;
    init.error_handler = nus_error_handler;
    init.p_gatt_queue  = &m_ble_gatt_queue;

    
    err_code = ble_nus_c_init(&m_ble_nus_c, &init);
    APP_ERROR_CHECK(err_code);
}

RE: How to discover custom service of peripheral

Henry_Chou — Tue, 22 Dec 2020 09:44:38 GMT

And your ble_evt_handler () should be ex:

Depend on your case

static void gatt_c_evt_handler(ble_gatt_c_t * p_gatt_c, ble_gatt_c_evt_t * p_gatt_c_evt)
{
switch (p_gatt_c_evt->evt_type)
{
case BLE_GATT_C_EVT_DISCOVERY_COMPLETE:
{
ret_code_t err_code;

NRF_LOG_INFO("BBQ BLE probe service discovered on conn_handle 0x%x\r\n",
p_gatt_c_evt->conn_handle);

err_code = app_button_enable();
APP_ERROR_CHECK(err_code);

// GATT service discovered. Enable notification of Read.
err_code = ble_gatt_c_read1_notif_enable(p_gatt_c);
APP_ERROR_CHECK(err_code);
err_code = ble_gatt_c_read2_notif_enable(p_gatt_c);
APP_ERROR_CHECK(err_code);

} break; // BLE_GATT_C_EVT_DISCOVERY_COMPLETE

case BLE_GATT_C_EVT_TEMPERATURE_NOTIFICATION:
{
data_state ^= p_gatt_c_evt->params.button.button_state;
NRF_LOG_INFO("Link 0x%x, Data state changed on peer to 0x%x\r\n",
p_gatt_c_evt->conn_handle,
data_state);
if (temp_T1>=0)
{
BLE_probe[p_gatt_c_evt->conn_handle].probe_T1 = temp_T1*10;
}
else
{
BLE_probe[p_gatt_c_evt->conn_handle].probe_T1 = 4000+abs(temp_T1)*10;
}
if (temp_T2>=0)
{
BLE_probe[p_gatt_c_evt->conn_handle].probe_T2 = temp_T2*10;
}
else
{
BLE_probe[p_gatt_c_evt->conn_handle].probe_T2 = 4000+abs(temp_T2)*10;
}
BLE_probe[p_gatt_c_evt->conn_handle].respon_time = temp_respon_time;
if (data_state==0xff)
{
bsp_board_led_on(LEDBUTTON_LED);
}
else
{
bsp_board_led_off(LEDBUTTON_LED);
}

} break; // BLE_GATT_C_EVT_BUTTON_NOTIFICATION

case BLE_GATT_C_EVT_STATUS_NOTIFICATION:
{
char temp_str[64]={0};
if (p_gatt_c_evt->params.button.button_state==0)
{
strcpy(temp_str,"Battery good.");
BLE_probe[p_gatt_c_evt->conn_handle].batt_status = 0xff;
}
else
{
strcpy(temp_str,"Low Battery.");
BLE_probe[p_gatt_c_evt->conn_handle].batt_status = 0x00;
}
NRF_LOG_INFO("Link 0x%x, Battery status: %s\r\n",
p_gatt_c_evt->conn_handle,
(uint32_t)temp_str);
check_sum=0;
check_sum = BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[5]+BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[4]+BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[3]
+BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[2]+BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[1]+BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[0]
+BLE_probe[p_gatt_c_evt->conn_handle].ble_name[0]+BLE_probe[p_gatt_c_evt->conn_handle].ble_name[1]+BLE_probe[p_gatt_c_evt->conn_handle].ble_name[2]
+BLE_probe[p_gatt_c_evt->conn_handle].ble_name[3]+BLE_probe[p_gatt_c_evt->conn_handle].ble_name[4]+BLE_probe[p_gatt_c_evt->conn_handle].connect_ID
+BLE_probe[p_gatt_c_evt->conn_handle].disconn_code+(BLE_probe[p_gatt_c_evt->conn_handle].probe_T1>>8)+(BLE_probe[p_gatt_c_evt->conn_handle].probe_T1&0xff)
+(BLE_probe[p_gatt_c_evt->conn_handle].probe_T2>>8)+(BLE_probe[p_gatt_c_evt->conn_handle].probe_T2&0xff)+BLE_probe[p_gatt_c_evt->conn_handle].batt_status
+BLE_probe[p_gatt_c_evt->conn_handle].respon_time;
sprintf(uart_tx_buff,"CT probe%d=%02x%02x%02x%02x%02x%02x,%s,%d,%x,%x,%x,%x,%x,%x\r\n",p_gatt_c_evt->conn_handle+1,BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[5],
BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[4],BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[3],BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[2],BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[1],BLE_probe[p_gatt_c_evt->conn_handle].ble_mac[0],
BLE_probe[p_gatt_c_evt->conn_handle].ble_name,BLE_probe[p_gatt_c_evt->conn_handle].connect_ID,BLE_probe[p_gatt_c_evt->conn_handle].disconn_code,BLE_probe[p_gatt_c_evt->conn_handle].probe_T1,BLE_probe[p_gatt_c_evt->conn_handle].probe_T2,
BLE_probe[p_gatt_c_evt->conn_handle].batt_status,BLE_probe[p_gatt_c_evt->conn_handle].respon_time,check_sum);
uart_serial_tx((uint8_t *)uart_tx_buff,strlen(uart_tx_buff));
//dbt_printf("%s",uart_tx_buff);
} break; // BLE_GATT_C_EVT_STATUS_NOTIFICATION

default:
// No implementation needed.
break;
}
}

RE: How to discover custom service of peripheral

mjr — Tue, 22 Dec 2020 09:27:54 GMT

Thank you. That's why I made it separately.
Is this the right way to do it?
But it hasn't been resolved...
What should I do... ...TT.

void MJR_c_on_db_disc_evt(ble_nus_c_t * p_ble_nus_c, ble_db_discovery_evt_t * p_evt)
{
    ble_nus_c_evt_t nus_c_evt;
    memset(&nus_c_evt,0,sizeof(ble_nus_c_evt_t));

    ble_gatt_db_char_t * p_chars = p_evt->params.discovered_db.charateristics;

    // Check if the NUS was discovered.
    if (    (p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE)
        &&  (p_evt->params.discovered_db.srv_uuid.uuid == MJR_LE_SERVICE_UUID)
        &&  (p_evt->params.discovered_db.srv_uuid.type == NUS_SERVICE_UUID_TYPE))
    {
        uint32_t i;
        for (i = 0; i < p_evt->params.discovered_db.char_count; i++)
        {
            switch (p_chars[i].characteristic.uuid.uuid)
            {
                case MJR_LE_NOTIFYCATION_UUID:

                    nus_c_evt.handles.nus_rx_handle = p_chars[i].characteristic.handle_value;
                    break;

                case MJR_LE_WRITE_NO_RESPONSE_UUID:

                    nus_c_evt.handles.nus_tx_handle = p_chars[i].characteristic.handle_value;
                    nus_c_evt.handles.nus_tx_cccd_handle = p_chars[i].cccd_handle;
                    break;

                default:
                    break;
            }
        }
        if (p_ble_nus_c->evt_handler != NULL)
        {
            nus_c_evt.conn_handle = p_evt->conn_handle;
            nus_c_evt.evt_type    = BLE_NUS_C_EVT_DISCOVERY_COMPLETE;
            p_ble_nus_c->evt_handler(p_ble_nus_c, &nus_c_evt);
        }
    }
}

static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    
    // ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);
    MJR_c_on_db_disc_evt(&m_ble_nus_c, p_evt);

}

RE: How to discover custom service of peripheral

Henry_Chou — Tue, 22 Dec 2020 09:14:22 GMT

That's my project code. I think the example code should be ble_nus_c_t & ble_nus_c_evt_t

The word meaning is the same.

Because my application is the thermal meter with GATT client service. Make some miss-understand. Sorry for that.

RE: How to discover custom service of peripheral

mjr — Tue, 22 Dec 2020 07:29:31 GMT

Thank you for your answer.

I'm using SDK17.

Could you tell me the location of "ble_gatt_c_t" and "ble_gatt_c_evt_t"???

RE: How to discover custom service of peripheral

Henry_Chou — Tue, 22 Dec 2020 06:39:20 GMT

For example discovery side:

static ble_uuid_t const m_nus_uuid =
{
.uuid = BLE_UUID_NUS_SERVICE,
.type = NUS_SERVICE_UUID_TYPE
};

err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_UUID_FILTER, &m_nus_uuid);

if the notify char. enable notify in your code

Then in your gatt discovery event add on char.

void ble_gatt_on_db_disc_evt(ble_gatt_c_t * p_ble_gatt_c, const ble_db_discovery_evt_t * p_evt)
{
// Check if the GATT Service was discovered.
if (p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE &&
p_evt->params.discovered_db.srv_uuid.uuid == BLE_UUID_NUS_SERVICE, &&
p_evt->params.discovered_db.srv_uuid.type == NUS_SERVICE_UUID_TYPE) //p_ble_gatt_c->uuid_type)
{
ble_gatt_c_evt_t evt;

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

uint32_t i;
for (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 UUID1_STATUS_CHAR:
evt.params.peer_db.read2_handle = p_char->characteristic.handle_value;
evt.params.peer_db.read2_cccd_handle = p_char->cccd_handle;
;
break;
case UUID2_STATUS_CHAR:
evt.params.peer_db.read1_handle = p_char->characteristic.handle_value;
evt.params.peer_db.read1_cccd_handle = p_char->cccd_handle;
break;

default:
break;
}
}

NRF_LOG_DEBUG("GATT Service discovered at peer.\r\n");
//If the instance has been assigned prior to db_discovery, assign the db_handles
if (p_ble_gatt_c->conn_handle != BLE_CONN_HANDLE_INVALID)
{
if ((p_ble_gatt_c->peer_gatt_db.write_handle == BLE_GATT_HANDLE_INVALID)&&
(p_ble_gatt_c->peer_gatt_db.read1_handle == BLE_GATT_HANDLE_INVALID)&&
(p_ble_gatt_c->peer_gatt_db.read1_cccd_handle == BLE_GATT_HANDLE_INVALID)&&
(p_ble_gatt_c->peer_gatt_db.read2_handle == BLE_GATT_HANDLE_INVALID)&&
(p_ble_gatt_c->peer_gatt_db.read2_cccd_handle == BLE_GATT_HANDLE_INVALID))
{
p_ble_gatt_c->peer_gatt_db = evt.params.peer_db;
}
}

p_ble_gatt_c->evt_handler(p_ble_gatt_c, &evt);

}
}

Get read or write char. in ble event handler.

static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)

{

}

RE: How to discover custom service of peripheral

mjr — Tue, 22 Dec 2020 06:20:12 GMT

Thank you for your prompt reply.

I know the uuid value. Can you tell me how to define it?

RE: How to discover custom service of peripheral

Henry_Chou — Tue, 22 Dec 2020 06:17:16 GMT

Do you know the service UUID & char. in peripheral side? If yes, you may define it in your code. If not, you may sniff the peripheral and try the service UUID and the characteristics data format. Sometimes the service UUID will be in advertisement data package.