ArduinoIoTCloudLPWAN.cpp

/*
   This file is part of ArduinoIoTCloud.

   Copyright 2019 ARDUINO SA (http://www.arduino.cc/)

   This software is released under the GNU General Public License version 3,
   which covers the main part of arduino-cli.
   The terms of this license can be found at:
   https://www.gnu.org/licenses/gpl-3.0.en.html

   You can be released from the requirements of the above licenses by purchasing
   a commercial license. Buying such a license is mandatory if you want to modify or
   otherwise use the software for commercial activities involving the Arduino
   software without disclosing the source code of your own applications. To purchase
   a commercial license, send an email to license@arduino.cc.
*/

/******************************************************************************
 * INCLUDE
 ******************************************************************************/

#include <AIoTC_Config.h>

#ifdef HAS_LORA

#include<ArduinoIoTCloudLPWAN.h>

#include "cbor/CBOREncoder.h"

/******************************************************************************
   CONSTANTS
 ******************************************************************************/

static size_t const CBOR_LORA_MSG_MAX_SIZE = 255;

/******************************************************************************
   LOCAL MODULE FUNCTIONS
 ******************************************************************************/

unsigned long getTime()
{
  return ArduinoCloud.getInternalTime();
}

/******************************************************************************
   CTOR/DTOR
 ******************************************************************************/

ArduinoIoTCloudLPWAN::ArduinoIoTCloudLPWAN()
: _state{State::ConnectPhy}
, _retryEnable{false}
, _maxNumRetry{5}
, _intervalRetry{AIOT_CONFIG_LPWAN_UPDATE_RETRY_DELAY_ms}
, _thing_property_container()
, _last_checked_property_index{0}
{

}

/******************************************************************************
 * PUBLIC MEMBER FUNCTIONS
 ******************************************************************************/

int ArduinoIoTCloudLPWAN::connected()
{
  return (_connection->check() == NetworkConnectionState::CONNECTED) ? 1 : 0;
}

int ArduinoIoTCloudLPWAN::begin(ConnectionHandler& connection, bool retry)
{
  _connection = &connection;
  _retryEnable = retry;
  _time_service.begin(nullptr);
  return 1;
}

void ArduinoIoTCloudLPWAN::update()
{
  /* Run through the state machine. */
  State next_state = _state;
  switch (_state)
  {
  case State::ConnectPhy: next_state = handle_ConnectPhy(); break;
  case State::SyncTime:   next_state = handle_SyncTime();   break;
  case State::Connected:  next_state = handle_Connected();  break;
  }
  _state = next_state;
}

void ArduinoIoTCloudLPWAN::printDebugInfo()
{
  DEBUG_INFO("***** Arduino IoT Cloud LPWAN - %s *****", AIOT_CONFIG_LIB_VERSION);
  DEBUG_INFO("Thing ID: %s", getThingId().c_str());
}

/******************************************************************************
 * PRIVATE MEMBER FUNCTIONS
 ******************************************************************************/

ArduinoIoTCloudLPWAN::State ArduinoIoTCloudLPWAN::handle_ConnectPhy()
{
  if (_connection->check() == NetworkConnectionState::CONNECTED)
    return State::SyncTime;
  else
    return State::ConnectPhy;
}

ArduinoIoTCloudLPWAN::State ArduinoIoTCloudLPWAN::handle_SyncTime()
{
  DEBUG_VERBOSE("LPWAN::%s internal clock configured to posix timestamp %lu", __FUNCTION__, _time_service.getTime());
  DEBUG_INFO("Connected to Arduino IoT Cloud");
  return State::Connected;
}

ArduinoIoTCloudLPWAN::State ArduinoIoTCloudLPWAN::handle_Connected()
{
  if (!connected())
  {
    DEBUG_ERROR("LPWAN::%s connection to gateway lost", __FUNCTION__);
    return State::ConnectPhy;
  }

  /* Check if a primitive property wrapper is locally changed. */
  updateTimestampOnLocallyChangedProperties(_thing_property_container);

  /* Decode available data. */
  if (_connection->available())
    decodePropertiesFromCloud();

  /* If properties need updating sent them to the cloud. */
  sendPropertiesToCloud();

  return State::Connected;
}

void ArduinoIoTCloudLPWAN::decodePropertiesFromCloud()
{
  uint8_t lora_msg_buf[CBOR_LORA_MSG_MAX_SIZE];
  size_t bytes_received;
  for (bytes_received = 0;
       _connection->available() && (bytes_received < CBOR_LORA_MSG_MAX_SIZE);
       bytes_received++)
  {
    lora_msg_buf[bytes_received] = _connection->read();
  }
  CBORDecoder::decode(_thing_property_container, lora_msg_buf, bytes_received);
}

void ArduinoIoTCloudLPWAN::sendPropertiesToCloud()
{
  int bytes_encoded = 0;
  uint8_t data[CBOR_LORA_MSG_MAX_SIZE];

  if (CBOREncoder::encode(_thing_property_container, data, sizeof(data), bytes_encoded, _last_checked_property_index, true) == CborNoError)
    if (bytes_encoded > 0)
      writeProperties(data, bytes_encoded);
}

int ArduinoIoTCloudLPWAN::writeProperties(const byte data[], int length)
{
  int retcode = _connection->write(data, length);
  int i = 0;
  while (_retryEnable && retcode < 0 && i < _maxNumRetry)
  {
    delay(_intervalRetry);
    retcode = _connection->write(data, length);
    i++;
  }

  return 1;
}

/******************************************************************************
 * EXTERN DEFINITION
 ******************************************************************************/

ArduinoIoTCloudLPWAN ArduinoCloud;

#endif