Notification for Peripheral

[Jackxl]

Hi, I have to send data with notification from central to peripheral, because I need save some data in peripheral device. What I have to do ? I test it on Adnroid 4.4 (my central for testing). I use this functions

static uint32_t cccd_configure(uint16_t conn_handle, uint16_t cccd_handle, bool enable)
{
    uint8_t buf[BLE_CCCD_VALUE_LEN];
    
    buf[0] = enable ? BLE_GATT_HVX_NOTIFICATION : 0;
    buf[1] = 0;
    
    const ble_gattc_write_params_t write_params = {
        .write_op = BLE_GATT_OP_WRITE_REQ,
        .flags    = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE,
        .handle   = cccd_handle,
        .offset   = 0,
        .len      = sizeof(buf),
        .p_value  = buf
    };

    return sd_ble_gattc_write(conn_handle, &write_params);
}

uint32_t ble_deufol_notif_enable(ble_deufol_t * p_deufol)
{
    VERIFY_PARAM_NOT_NULL(p_deufol);

    if ( (p_deufol->conn_handle == BLE_CONN_HANDLE_INVALID)
       ||(p_deufol->common_handles.cccd_handle == BLE_GATT_HANDLE_INVALID)
       )
    {
        return NRF_ERROR_INVALID_STATE;
    }
    return cccd_configure(p_deufol->conn_handle,p_deufol->common_handles.cccd_handle, true);
}

after peripheral device is connected, but I get event BLE_GATTS_EVT_WRITE instead BLE_GATTC_EVT_HVX

I enable notification on Android

byte[] enableNotificationValue = new byte[BluetoothGattDescriptor.EnableNotificationValue.Count];
                            for (int i = 0; i < enableNotificationValue.Length; i++)
                            {
                                enableNotificationValue[i] = BluetoothGattDescriptor.EnableNotificationValue[i];
                            }
                            selectedGattDescriptor.SetValue(enableNotificationValue);
                            gatClient.WriteDescriptor(selectedGattDescriptor);

[Vyacheslav Lebets]

Hi. You code in "cccd_configure" was written to use in central, but in you case, you say that device is peripherial. Android in you case is Master and cannot send notification, Android send "Write" command to write data to the cccd value, so you receive "BLE_GATTS_EVT_WRITE"

Best, VL