RE: How to make custom characteristic with Indication?

Al Bundy — Tue, 08 Sep 2015 13:36:17 GMT

It works now, thanks.

RE: How to make custom characteristic with Indication?

MartinBL — Mon, 07 Sep 2015 14:16:50 GMT

Try to use sd_ble_gatts_hvx(). "hvx" stands for Handle Value x, where x can be Indication or Notification. Notification/Indication Difference.

This is how the heart rate example ble_app_hrs example in SDK 9 sends a notification:

uint32_t ble_hrs_heart_rate_measurement_send(ble_hrs_t * p_hrs, uint16_t heart_rate)
{
    uint32_t err_code;

    // Send value if connected and notifying
    if (p_hrs->conn_handle != BLE_CONN_HANDLE_INVALID)
    {
        uint8_t                encoded_hrm[MAX_HRM_LEN];
        uint16_t               len;
        uint16_t               hvx_len;
        ble_gatts_hvx_params_t hvx_params;

        len     = hrm_encode(p_hrs, heart_rate, encoded_hrm);
        hvx_len = len;

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

        hvx_params.handle = p_hrs->hrm_handles.value_handle;
        hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
        hvx_params.offset = 0;
        hvx_params.p_len  = &hvx_len;
        hvx_params.p_data = encoded_hrm;

        err_code = sd_ble_gatts_hvx(p_hrs->conn_handle, &hvx_params);
        if ((err_code == NRF_SUCCESS) && (hvx_len != len))
        {
            err_code = NRF_ERROR_DATA_SIZE;
        }
    }
    else
    {
        err_code = NRF_ERROR_INVALID_STATE;
    }

    return err_code;
}