NTPClient/NTPClient.cpp

/**
 * The MIT License (MIT)
 * Copyright (c) 2015 by Fabrice Weinberg
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "NTPClient.h"

NTPClient::NTPClient(UDP& udp) {
  this->_udp            = &udp;
}

NTPClient::NTPClient(UDP& udp, int timeOffset) {
  this->_udp            = &udp;
  this->_timeOffset     = timeOffset;
}

NTPClient::NTPClient(UDP& udp, const char* poolServerName) {
  this->_udp            = &udp;
  this->_poolServerName = poolServerName;
}

NTPClient::NTPClient(UDP& udp, const char* poolServerName, int timeOffset) {
  this->_udp            = &udp;
  this->_timeOffset     = timeOffset;
  this->_poolServerName = poolServerName;
}

NTPClient::NTPClient(UDP& udp, const char* poolServerName, int timeOffset, int updateInterval) {
  this->_udp            = &udp;
  this->_timeOffset     = timeOffset;
  this->_poolServerName = poolServerName;
  this->_updateInterval = updateInterval;
}

void NTPClient::begin() {
  this->begin(NTP_DEFAULT_LOCAL_PORT);
}

void NTPClient::begin(int port) {
  this->_port = port;

  this->_udp->begin(this->_port);

  this->_udpSetup = true;
}

bool NTPClient::checkResponse() {

  if (this->_udp->parsePacket()) {
    this->_lastUpdate = millis();
    this->_lastRequest = 0; // no outstanding request
    this->_udp->read(this->_packetBuffer, NTP_PACKET_SIZE);

    unsigned long highWord = word(this->_packetBuffer[40], this->_packetBuffer[41]);
    unsigned long lowWord = word(this->_packetBuffer[42], this->_packetBuffer[43]);
    // combine the four bytes (two words) into a long integer
    // this is NTP time (seconds since Jan 1 1900):
    unsigned long secsSince1900 = highWord << 16 | lowWord;

    this->_currentEpoc = secsSince1900 - SEVENZYYEARS;

    highWord = word(this->_packetBuffer[44], this->_packetBuffer[45]);
    lowWord = word(this->_packetBuffer[46], this->_packetBuffer[47]);
    this->_currentFraction = highWord << 16 | lowWord;

    // if the user has set a callback function for when the time is updated, call it
    if (_updateCallback) { _updateCallback(this); }

    return true;
  } else {
    return false;
  }
}

bool NTPClient::forceUpdate() {
  #ifdef DEBUG_NTPClient
    Serial.println("Update from NTP Server");
  #endif

  this->sendNTPPacket();

  // Wait till data is there or timeout...
  byte timeout = 0;
  bool cb = 0;
  do {
    delay ( 10 );
    cb = this->checkResponse();
    if (timeout > 100) return false; // timeout after 1000 ms
    timeout++;
  } while (cb == false);

  return true;
}

bool NTPClient::update() {
  bool updated = false;
  unsigned long now = millis();

  if ( ((_lastRequest == 0) && (_lastUpdate == 0))                          // Never requested or updated
    || ((_lastRequest == 0) && ((now - _lastUpdate) >= _updateInterval))    // Update after _updateInterval
    || ((_lastRequest != 0) && ((now - _lastRequest) > _retryInterval)) ) { // Update if there was no response to the request

    // setup the UDP client if needed
    if (!this->_udpSetup) {
      this->begin();
    }

    this->sendNTPPacket();
  }

  if (_lastRequest) {
    updated = checkResponse();
  }

  return updated;
}

bool NTPClient::updated() {
  return (_currentEpoc != 0);
}

unsigned long NTPClient::getEpochTime() {
  return this->_timeOffset + // User offset
         this->_currentEpoc + // Epoc returned by the NTP server
         ((millis() - this->_lastUpdate + (_currentFraction / FRACTIONSPERMILLI)) / 1000); // Time since last update
}

unsigned long long NTPClient::getEpochMillis() {
  unsigned long long epoch;

  epoch = this->_timeOffset;                     // user offset
  epoch += _currentEpoc;                         // last time returned via server
  epoch *= 1000;                                 // convert to millis
  epoch += _currentFraction / FRACTIONSPERMILLI; // add the fraction from the server
  epoch += millis() - this->_lastUpdate;         // add the millis that have passed since the last update

  return epoch;
}

int NTPClient::getDay() {
  return (((this->getEpochTime()  / 86400L) + 4 ) % 7); //0 is Sunday
}
int NTPClient::getHours() {
  return ((this->getEpochTime()  % 86400L) / 3600);
}
int NTPClient::getMinutes() {
  return ((this->getEpochTime() % 3600) / 60);
}
int NTPClient::getSeconds() {
  return (this->getEpochTime() % 60);
}

String NTPClient::getFormattedTime() {
  unsigned long rawTime = this->getEpochTime();
  unsigned long hours = (rawTime % 86400L) / 3600;
  String hoursStr = hours < 10 ? "0" + String(hours) : String(hours);

  unsigned long minutes = (rawTime % 3600) / 60;
  String minuteStr = minutes < 10 ? "0" + String(minutes) : String(minutes);

  unsigned long seconds = rawTime % 60;
  String secondStr = seconds < 10 ? "0" + String(seconds) : String(seconds);

  return hoursStr + ":" + minuteStr + ":" + secondStr;
}

void NTPClient::end() {
  this->_udp->stop();

  this->_udpSetup = false;
}

void NTPClient::setTimeOffset(int timeOffset) {
  this->_timeOffset     = timeOffset;
}

void NTPClient::setUpdateInterval(int updateInterval) {
  this->_updateInterval = updateInterval;
}

void NTPClient::setUpdateCallback(NTPUpdateCallbackFunction f) {
  _updateCallback = f;
}

void NTPClient::sendNTPPacket() {
  // set all bytes in the buffer to 0
  memset(this->_packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  // (see URL above for details on the packets)
  this->_packetBuffer[0] = 0b11100011;   // LI, Version, Mode
  this->_packetBuffer[1] = 0;     // Stratum, or type of clock
  this->_packetBuffer[2] = 6;     // Polling Interval
  this->_packetBuffer[3] = 0xEC;  // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  this->_packetBuffer[12]  = 49;
  this->_packetBuffer[13]  = 0x4E;
  this->_packetBuffer[14]  = 49;
  this->_packetBuffer[15]  = 52;

  // all NTP fields have been given values, now
  // you can send a packet requesting a timestamp:
  this->_udp->beginPacket(this->_poolServerName, 123); //NTP requests are to port 123
  this->_udp->write(this->_packetBuffer, NTP_PACKET_SIZE);
  this->_udp->endPacket();

  this->_lastRequest = millis();

}