UdpNTPClient.ino

/****************************************************************************************************************************
  UdpNTPClient.ino - Simple Arduino web server sample for ESP8266 AT-command shield
  EthernetWebServer is a library for the Ethernet shields to run WebServer

  Based on and modified from ESP8266 https://github.com/esp8266/Arduino/releases
  Built by Khoi Hoang https://github.com/khoih-prog/EthernetWebServer
  Licensed under MIT license
 *****************************************************************************************************************************/
/*
   The Arduino board communicates with the shield using the SPI bus. This is on digital pins 11, 12, and 13 on the Uno
   and pins 50, 51, and 52 on the Mega. On both boards, pin 10 is used as SS. On the Mega, the hardware SS pin, 53,
   is not used to select the Ethernet controller chip, but it must be kept as an output or the SPI interface won't work.
*/

#include "defines.h"

char timeServer[]         = "time.nist.gov";  // NTP server
unsigned int localPort    = 2390;             // local port to listen for UDP packets

const int NTP_PACKET_SIZE = 48;       // NTP timestamp is in the first 48 bytes of the message
const int UDP_TIMEOUT     = 2000;     // timeout in miliseconds to wait for an UDP packet to arrive

byte packetBuffer[NTP_PACKET_SIZE];   // buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

// send an NTP request to the time server at the given address
void sendNTPpacket(char *ntpSrv)
{
  // set all bytes in the buffer to 0
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  // (see URL above for details on the packets)

  packetBuffer[0] = 0b11100011;   // LI, Version, Mode
  packetBuffer[1] = 0;     // Stratum, or type of clock
  packetBuffer[2] = 6;     // Polling Interval
  packetBuffer[3] = 0xEC;  // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuffer[12]  = 49;
  packetBuffer[13]  = 0x4E;
  packetBuffer[14]  = 49;
  packetBuffer[15]  = 52;

  // all NTP fields have been given values, now
  // you can send a packet requesting a timestamp:
  Udp.beginPacket(ntpSrv, 123); //NTP requests are to port 123

  Udp.write(packetBuffer, NTP_PACKET_SIZE);

  Udp.endPacket();
}

void setup()
{
  SerialDebug.begin(115200);

  while (!SerialDebug && millis() < 5000);

  SerialDebug.print("\nStart UdpNTPClient on ");
  SerialDebug.print(BOARD_NAME);
  SerialDebug.print(F(" with "));
  SerialDebug.println(SHIELD_TYPE);
  SerialDebug.println(ETHERNET_WEBSERVER_VERSION);

#if USE_ETHERNET_PORTENTA_H7
  ET_LOGWARN(F("======== USE_PORTENTA_H7_ETHERNET ========"));
#elif USE_NATIVE_ETHERNET
  ET_LOGWARN(F("======== USE_NATIVE_ETHERNET ========"));
#elif USE_ETHERNET_GENERIC
  ET_LOGWARN(F("=========== USE_ETHERNET_GENERIC ==========="));
#elif USE_ETHERNET_ESP8266
  ET_LOGWARN(F("=========== USE_ETHERNET_ESP8266 ==========="));
#elif USE_ETHERNET_ENC
  ET_LOGWARN(F("=========== USE_ETHERNET_ENC ==========="));
#else
  ET_LOGWARN(F("========================="));
#endif

#if !(USE_NATIVE_ETHERNET || USE_ETHERNET_PORTENTA_H7)

#if (USING_SPI2)
#if defined(CUR_PIN_MISO)
  ET_LOGWARN(F("Default SPI pinout:"));
  ET_LOGWARN1(F("MOSI:"), CUR_PIN_MOSI);
  ET_LOGWARN1(F("MISO:"), CUR_PIN_MISO);
  ET_LOGWARN1(F("SCK:"),  CUR_PIN_SCK);
  ET_LOGWARN1(F("SS:"),   CUR_PIN_SS);
  ET_LOGWARN(F("========================="));
#endif
#else
  ET_LOGWARN(F("Default SPI pinout:"));
  ET_LOGWARN1(F("MOSI:"), MOSI);
  ET_LOGWARN1(F("MISO:"), MISO);
  ET_LOGWARN1(F("SCK:"),  SCK);
  ET_LOGWARN1(F("SS:"),   SS);
  ET_LOGWARN(F("========================="));
#endif

#if defined(ESP8266)
  // For ESP8266, change for other boards if necessary
#ifndef USE_THIS_SS_PIN
#define USE_THIS_SS_PIN   D2    // For ESP8266
#endif

  ET_LOGWARN1(F("ESP8266 setCsPin:"), USE_THIS_SS_PIN);

#if ( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )
  // For ESP8266
  // Pin                D0(GPIO16)    D1(GPIO5)    D2(GPIO4)    D3(GPIO0)    D4(GPIO2)    D8
  // EthernetGeneric    X                 X            X            X            X        0
  // Ethernet_ESP8266   0                 0            0            0            0        0
  // D2 is safe to used for Ethernet, Ethernet2, Ethernet3, EthernetLarge libs
  // Must use library patch for Ethernet, EthernetLarge libraries
  Ethernet.init (USE_THIS_SS_PIN);

#elif USE_CUSTOM_ETHERNET

  // You have to add initialization for your Custom Ethernet here
  // This is just an example to setCSPin to USE_THIS_SS_PIN, and can be not correct and enough
  Ethernet.init(USE_THIS_SS_PIN);

#endif  //( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )

#elif defined(ESP32)

  // You can use Ethernet.init(pin) to configure the CS pin
  //Ethernet.init(10);  // Most Arduino shields
  //Ethernet.init(5);   // MKR ETH shield
  //Ethernet.init(0);   // Teensy 2.0
  //Ethernet.init(20);  // Teensy++ 2.0
  //Ethernet.init(15);  // ESP8266 with Adafruit Featherwing Ethernet
  //Ethernet.init(33);  // ESP32 with Adafruit Featherwing Ethernet

#ifndef USE_THIS_SS_PIN
#define USE_THIS_SS_PIN   5   //22    // For ESP32
#endif

  ET_LOGWARN1(F("ESP32 setCsPin:"), USE_THIS_SS_PIN);

  // For other boards, to change if necessary
#if ( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )
  // Must use library patch for Ethernet, EthernetLarge libraries
  // ESP32 => GPIO2,4,5,13,15,21,22 OK with Ethernet, Ethernet2, EthernetLarge
  // ESP32 => GPIO2,4,5,15,21,22 OK with Ethernet3

  //Ethernet.setCsPin (USE_THIS_SS_PIN);
  Ethernet.init (USE_THIS_SS_PIN);

#elif USE_CUSTOM_ETHERNET

  // You have to add initialization for your Custom Ethernet here
  // This is just an example to setCSPin to USE_THIS_SS_PIN, and can be not correct and enough
  Ethernet.init(USE_THIS_SS_PIN);

#endif  //( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )

#elif ETHERNET_USE_RPIPICO

  pinMode(USE_THIS_SS_PIN, OUTPUT);
  digitalWrite(USE_THIS_SS_PIN, HIGH);

  // ETHERNET_USE_RPIPICO, use default SS = 5 or 17
#ifndef USE_THIS_SS_PIN
#if defined(ARDUINO_ARCH_MBED)
#define USE_THIS_SS_PIN   5     // For Arduino Mbed core
#else
#define USE_THIS_SS_PIN   17    // For E.Philhower core
#endif
#endif

  ET_LOGWARN1(F("RPIPICO setCsPin:"), USE_THIS_SS_PIN);

  // For other boards, to change if necessary
#if ( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )
  // Must use library patch for Ethernet, EthernetLarge libraries
  // For RPI Pico using Arduino Mbed RP2040 core
  // SCK: GPIO2,  MOSI: GPIO3, MISO: GPIO4, SS/CS: GPIO5
  // For RPI Pico using E. Philhower RP2040 core
  // SCK: GPIO18,  MOSI: GPIO19, MISO: GPIO16, SS/CS: GPIO17
  // Default pin 5/17 to SS/CS

  //Ethernet.setCsPin (USE_THIS_SS_PIN);
  Ethernet.init (USE_THIS_SS_PIN);

#endif    //( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )

#else   //defined(ESP8266)
  // unknown board, do nothing, use default SS = 10
#ifndef USE_THIS_SS_PIN
#define USE_THIS_SS_PIN   10    // For other boards
#endif

#if defined(BOARD_NAME)
  ET_LOGWARN3(F("Board :"), BOARD_NAME, F(", setCsPin:"), USE_THIS_SS_PIN);
#else
  ET_LOGWARN1(F("Unknown board setCsPin:"), USE_THIS_SS_PIN);
#endif

  // For other boards, to change if necessary
#if ( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC || USE_NATIVE_ETHERNET )
  // Must use library patch for Ethernet, Ethernet2, EthernetLarge libraries

  Ethernet.init (USE_THIS_SS_PIN);

#elif USE_CUSTOM_ETHERNET

  // You have to add initialization for your Custom Ethernet here
  // This is just an example to setCSPin to USE_THIS_SS_PIN, and can be not correct and enough
  Ethernet.init(USE_THIS_SS_PIN);

#endif  //( USE_ETHERNET_GENERIC || USE_ETHERNET_ENC )

#endif    // defined(ESP8266)

#endif    // #if !(USE_NATIVE_ETHERNET)

  // start the ethernet connection and the server:
  // Use DHCP dynamic IP and random mac
  uint16_t index = millis() % NUMBER_OF_MAC;
  // Use Static IP
  //Ethernet.begin(mac[index], ip);
  Ethernet.begin(mac[index]);

#if !(USE_NATIVE_ETHERNET || USE_ETHERNET_PORTENTA_H7)
  ET_LOGWARN(F("========================="));

#if defined( ESP32 )
  // Just info to know how to connect correctly
  // To change for other SPI
  ET_LOGWARN(F("Currently Used SPI pinout:"));
  ET_LOGWARN1(F("MOSI:"), PIN_MOSI);
  ET_LOGWARN1(F("MISO:"), PIN_MISO);
  ET_LOGWARN1(F("SCK:"),  PIN_SCK);
  ET_LOGWARN1(F("SS:"),   PIN_SS);
#else
#if defined(CUR_PIN_MISO)
  ET_LOGWARN(F("Currently Used SPI pinout:"));
  ET_LOGWARN1(F("MOSI:"), CUR_PIN_MOSI);
  ET_LOGWARN1(F("MISO:"), CUR_PIN_MISO);
  ET_LOGWARN1(F("SCK:"),  CUR_PIN_SCK);
  ET_LOGWARN1(F("SS:"),   CUR_PIN_SS);
#else
  ET_LOGWARN(F("Currently Used SPI pinout:"));
  ET_LOGWARN1(F("MOSI:"), MOSI);
  ET_LOGWARN1(F("MISO:"), MISO);
  ET_LOGWARN1(F("SCK:"),  SCK);
  ET_LOGWARN1(F("SS:"),   SS);
#endif
#endif

  ET_LOGWARN(F("========================="));

#elif (USE_ETHERNET_PORTENTA_H7)

  if (Ethernet.hardwareStatus() == EthernetNoHardware)
  {
    SerialDebug.println("No Ethernet found. Stay here forever");

    while (true)
    {
      delay(1); // do nothing, no point running without Ethernet hardware
    }
  }

  if (Ethernet.linkStatus() == LinkOFF)
  {
    SerialDebug.println("Not connected Ethernet cable");
  }

#endif

  SerialDebug.print(F("Using mac index = "));
  SerialDebug.println(index);

  SerialDebug.print(F("Connected! IP address: "));
  SerialDebug.println(Ethernet.localIP());

  Udp.begin(localPort);
}

void loop()
{
  sendNTPpacket(timeServer); // send an NTP packet to a time server

  // wait for a reply for UDP_TIMEOUT miliseconds
  unsigned long startMs = millis();

  while (!Udp.available() && (millis() - startMs) < UDP_TIMEOUT) {}

  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();

  if (packetSize)
  {
    SerialDebug.print(F("UDP Packet received, size "));
    SerialDebug.println(packetSize);
    SerialDebug.print(F("From "));
    IPAddress remoteIp = Udp.remoteIP();
    SerialDebug.print(remoteIp);
    SerialDebug.print(F(", port "));
    SerialDebug.println(Udp.remotePort());

    // We've received a packet, read the data from it into the buffer
    Udp.read(packetBuffer, NTP_PACKET_SIZE);

    // the timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, esxtract the two words:

    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], 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;

    SerialDebug.print(F("Seconds since Jan 1 1900 = "));
    SerialDebug.println(secsSince1900);

    // now convert NTP time into )everyday time:
    SerialDebug.print(F("Unix time = "));
    // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
    const unsigned long seventyYears = 2208988800UL;
    // subtract seventy years:
    unsigned long epoch = secsSince1900 - seventyYears;
    // print Unix time:
    SerialDebug.println(epoch);

    // print the hour, minute and second:
    SerialDebug.print(F("The UTC time is "));       // UTC is the time at Greenwich Meridian (GMT)
    SerialDebug.print((epoch  % 86400L) / 3600); // print the hour (86400 equals secs per day)
    SerialDebug.print(F(":"));

    if (((epoch % 3600) / 60) < 10)
    {
      // In the first 10 minutes of each hour, we'll want a leading '0'
      SerialDebug.print(F("0"));
    }

    SerialDebug.print((epoch  % 3600) / 60); // print the minute (3600 equals secs per minute)
    SerialDebug.print(F(":"));

    if ((epoch % 60) < 10)
    {
      // In the first 10 seconds of each minute, we'll want a leading '0'
      SerialDebug.print(F("0"));
    }

    SerialDebug.println(epoch % 60); // print the second
  }

  // wait ten seconds before asking for the time again
  delay(10000);
}