Cómo utilizar NTP con el Aduino Leonardo

#include <Wire.h>

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// You can find the TimeLib and the ds3231 library on my github page https://github.com/Sani7/NTP-config_reader-DS3231

​

#include <ds3231.h>

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struct ts t;

​

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#include <TimeLib.h>    

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#define ssid "SSID"     // Put you're WiFi SSID here

#define pswd "PSWD"     // Put you're WiFi PSWD here

​

// NTP stuff

// Get Time from NTP server (Network Time Protocol, RFC 5905)

// NTP uses UDP/IP packets for data transfer because of the fast

// connection setup and response times.

​

// The official port number for the NTP (that ntpd and ntpdate listen and talk to) is 123.

// The unit of time is in seconds, and the epoch is 1 January 1900.

// its gives you UTC time, which is the time at Greenwich Meridian (GMT)

// The NTP timestamp is a 64 bit binary value, built from an unsigned 32-bit seconds value

// and a 32-bit fractional part. In this notation the value 3.5 would be represented by the 64-bit string:

// 0000|0000|0000|0000|0000|0000|0000|0011 . 1000|0000|0000|0000|0000|0000|0000|0000

// If you take all the bits as a 64 bit unsigned integer,

// store it in a floating point variable with at least 64 bits of mantissa (usually double)

// and do a floating point divide by 2^32, you'll get the right answer.

// On a standard arduino unfortunately we don't have 64 bits doubles.

// but most RTC have just second level info, so no need to get the second half (or first byte possibly)

​

// Only the first four bytes of an outgoing NTP packet need to be set for what we want to achieve

// appropriately, the rest can be whatever.

//The header fields of the NTP message are as follows:

//

//LI  Leap Indicator (2 bits)

//This field indicates whether the last minute of the current day is to have a leap second applied. The field values follow:

//0: No leap second adjustment

//1: Last minute of the day has 61 seconds

//2: Last minute of the day has 59 seconds

//3: Clock is unsynchronized

//

//VN  NTP Version Number (3 bits) (current version is 4).

//

//Mode  NTP packet mode (3 bits)

//The values of the Mode field follow:

//0: Reserved

//1: Symmetric active

//2: Symmetric passive

//3: Client

//4: Server

//5: Broadcast

//6: NTP control message

//7: Reserved for private use

//

//Stratum level of the time source (8 bits)

//The values of the Stratum field follow:

//0: Unspecified or invalid

//1: Primary server

//2–15: Secondary server

//16: Unsynchronized

//17–255: Reserved

//

//Poll  Poll interval (8-bit signed integer)

//The log2 value of the maximum interval between successive NTP messages, in seconds.

//

//Precision Clock precision (8-bit signed integer)

//The precision of the system clock, in log2 seconds.

​

static const unsigned long ntpFirstFourBytes = 0xEC0600E3; // NTP request header, first 32 bits

const uint8_t NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message

​

​

// after a successful querry we will get a 48 byte answer from the NTP server.

// To understand the structure of an NTP querry and answer

// see http://www.cisco.com/c/en/us/about/press/internet-protocol-journal/back-issues/table-contents-58/154-ntp.html

// so if we want to read the "Transmit Timestamp" then we need to

// Read the integer part which are bytes 40,41,42,43

// if we want to round to the nearest second if we want some accuracy

// Then fractionary part are byte 44,45,46,47

// if it is greater than 500ms byte 44 will be > 128

// and thus by only checking byte 44 of the answer we can round to the next second;

// 90% of the NTP servers have network delays below 100ms

// We can also account for an assumed averaged network delay of 50ms, and thus instead of

// comparing with 128 you can compare with (0.5s - 0.05s) * 256 = 115;

​

#define SECONDROUNDINGTHRESHOLD 115

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// the epoch for NTP starts in year 1900 while the epoch in UNIX starts in 1970

// Unix time starts on Jan 1 1970. 7O years difference in seconds, that's 2208988800 seconds

#define SEVENTYYEARS 2208988800UL

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// to transform a number of seconds into a current time you need to do some maths

#define NUMBEROFSECONDSPERDAY 86400UL

#define NUMBEROFSECONDSPERHOUR 3600UL

#define NUMBEROFSECONDSPERMINUTE 60UL

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// you might not leave in UTC time zone, set up your delta time in hours

#define UTC_DELTA_HOURS 2

/*Set offset time to adjust for your timezone, for example:

  * GMT +1

  * GMT +2

  * GMT +8

  * GMT -1

  * GMT 0 

 */

#define UTC_DELTA_MINUTES 0

const long UTC_DELTA = ((UTC_DELTA_HOURS * NUMBEROFSECONDSPERHOUR) + (UTC_DELTA_MINUTES*NUMBEROFSECONDSPERMINUTE));

​

// MANAGE the ESP8266. Using an ESP - 01

// we control the reset pin through the arduino

#define hardRestPIN 22

#define SHORT_PAUSE 1000UL

#define LONG_PAUSE  5000UL

const char * OK_STR = "OK\r\n";

​

​

#define ESPSERIALBAUD 115200 // Set to whatever is the default for your ESP. 

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/* 

 *  =====================================================================================

 *  --------------------------------------

 *   emptyESP_RX waits for duration ms

 *   and get rid of anything arriving

 *   on the ESP Serial port during that delay

 *   --------------------------------------

 */

void emptyESP_RX(unsigned long duration)

{

  unsigned long currentTime;

  currentTime = millis();

  while (millis() - currentTime <= duration) {

    if (Serial1.available() > 0) Serial1.read();

  }

}

​

/* 

 *  --------------------------------------

 *  waitForString wait max for duration ms

 *  while checking if endMarker string is received

 *  on the ESP Serial port

 *  returns a boolean stating if the marker

 *  was found

 *  --------------------------------------

 */

​

boolean waitForString(const char * endMarker, unsigned long duration)

{

  int localBufferSize = strlen(endMarker); // we won't need an \0 at the end

  char localBuffer[localBufferSize];

  int index = 0;

  boolean endMarkerFound = false;

  unsigned long currentTime;

​

  memset(localBuffer, '\0', localBufferSize); // clear buffer

​

  currentTime = millis();

  while (millis() - currentTime <= duration) {

    if (Serial1.available() > 0) {

      if (index == localBufferSize) index = 0;

      localBuffer[index] = (uint8_t) Serial1.read();

      endMarkerFound = true;

      for (int i = 0; i < localBufferSize; i++) {

        if (localBuffer[(index + 1 + i) % localBufferSize] != endMarker[i]) {

          endMarkerFound = false;

          break;

        }

      }

      index++;

    }

    if (endMarkerFound) break;

  }

  return endMarkerFound;

}

​

​

/* --------------------------------------

 * espATCommand executes an AT commmand

 * checks if endMarker string is received

 * on the ESP Serial port for max duration ms

 * returns a boolean stating if the marker

 * was found

 *  --------------------------------------

 */

​

boolean espATCommand(const char * command, const char * endMarker, unsigned long duration)

{

  Serial1.println(command);

  return waitForString(endMarker, duration);

}

​

​

/* --------------------------------------

 * epochUnixNTP returns the UNIX time

 * number of seconds sice Jan 1 1970

 * adjusted for timezoneDeltaFromUTC

 * --------------------------------------

 */

​

unsigned long epochUnixNTP()

{

  unsigned long secsSince1900 = 0UL;

  unsigned long epochUnix;

​

  // AT+CIPSTART="UDP","be.pool.ntp.org",123

  espATCommand("AT+CIPSTART=\"UDP\",\"be.pool.ntp.org\",123", OK_STR, LONG_PAUSE);

  espATCommand("AT+CIPSEND=48", OK_STR, SHORT_PAUSE); //send 48 (NTP_PACKET_SIZE) bytes

  emptyESP_RX(1000UL); // empty the buffer (we get a > character)

  Serial1.write((char*) &ntpFirstFourBytes, NTP_PACKET_SIZE); // the first 4 bytes matters, then we don't care, whatever is in the memory will do

​

  // skip  AT command answer ("Recv 48 bytes\r\n\r\nSEND OK\r\n\r\n+IPD,48:")

  waitForString(":", SHORT_PAUSE);

​

  // read the NTP packet, extract the TRANSMIT TIMESTAMP in Seconds from bytes 40,41,42,43

  for (int i = 0; i < NTP_PACKET_SIZE; i++) {

    while (!Serial1.available());

    int c = Serial1.read();

    if ((i >= 40) && (i < 44))  secsSince1900 = (secsSince1900 << 8) + (unsigned long) ((uint8_t) (c & (int) 0x00FF)); // Read the integer part of sending time

    else if (i == 44) secsSince1900 += (((uint8_t) c) > SECONDROUNDINGTHRESHOLD ? 1 : 0);

  }

​

  // subtract seventy years:

  epochUnix = secsSince1900 - SEVENTYYEARS;

​

​

  espATCommand("AT+CIPCLOSE", OK_STR, SHORT_PAUSE); // close connection

  return epochUnix + UTC_DELTA;

}

​

// =====================================================================================

​

void setup()

{

  Serial.begin(115200); while (!Serial);

  Serial1.begin(ESPSERIALBAUD); while (!Serial1);

​

  //reset the device (pull the RST pin to ground)

  digitalWrite(hardRestPIN, LOW);

  delay(100);

  digitalWrite(hardRestPIN, HIGH);

​

  // connect to my WiFi network

  espATCommand("AT+RESTORE", "ready", LONG_PAUSE); // reset

  emptyESP_RX(SHORT_PAUSE);

  espATCommand("AT", OK_STR, SHORT_PAUSE); //is all OK?

  espATCommand("AT+CWMODE=1", OK_STR, SHORT_PAUSE); //Set the wireless mode

  espATCommand("AT+CWQAP", OK_STR, SHORT_PAUSE);   //disconnect  - it shouldn't be but just to make sure

  espATCommand("AT+CWJAP=\""ssid"\",\""pswd"\"", "OK", LONG_PAUSE); // connect to wifi

  espATCommand("AT+CIPMUX=0", OK_STR, SHORT_PAUSE); //set the single connection mode

  Wire.begin();

  // Initialize the control register of the DS3231 module

  DS3231_init(0x00);

  // Get epochTime and convert it to hours, minutes, seconds, day, month, year

  unsigned long epochTime = epochUnixNTP();

  t.hour=hour(epochTime); 

  t.min=minute(epochTime);

  t.sec=second(epochTime);

  t.mday=day(epochTime);

  t.mon=month(epochTime);

  t.year=year(epochTime);

  // Write date and time to the DS3231 module

  DS3231_set(t);

}

​

​

void loop()

{

  // Get date and time from the DS3231 module and print it in the serial monitor

  DS3231_get(&t);

  char currentTime[8];

  sprintf(currentTime, "%d:%d:%d", t.hour, t.min, t.sec);

  Serial.print("Current time: ");

  Serial.println(currentTime);

  char currentDate[9];

  sprintf(currentDate, "%d/%d/%d", t.mday, t.mon, t.year);

  Serial.print("Current date: ");

  Serial.println(currentDate);

  delay(1000);

}