Arduino: Ethernet NTP Time Sync - Revision history

Onnowpurbo: /* Code */

2018-05-29T04:37:51Z

Code

Onnowpurbo at 14:21, 28 May 2018

2018-05-28T14:21:26Z

Onnowpurbo: Created page with " // NTP time issue // IDE 1.0.3 // DHCP Server required // Arduino Mega2560 + Ethernetshield for Mega with SD-slot // #include #include #include..."

2018-05-28T14:20:48Z

Created page with " // NTP time issue // IDE 1.0.3 // DHCP Server required // Arduino Mega2560 + Ethernetshield for Mega with SD-slot // #include <MsTimer2.h> #include <Time.h> #include..."

New page

// NTP time issue
// IDE 1.0.3
// DHCP Server required
// Arduino Mega2560 + Ethernetshield for Mega with SD-slot

// #include <MsTimer2.h>
#include <Time.h>
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

#define SD_CS 4

// Ethernet library configuration
byte mac[] = { 0x24, 0x7B, 0xA2, 0x4A, 0x52, 0x10 };
IPAddress timeServer(128, 138, 140, 44 );

/* ALTER THESE VARIABLES AT YOUR OWN RISK */
// local port to listen for UDP packets
unsigned int localPort = 8888;
const int NTP_PACKET_SIZE= 48;
byte packetBuffer[NTP_PACKET_SIZE];
EthernetUDP Udp;

void setup() {

// disable SD SPI Chip Select
pinMode(SD_CS,OUTPUT);

Serial.begin(9600);
Serial.println("Wait for DHCP Server");
if (Ethernet.begin(mac) == 0) { // start Ethernet by DHCP conf.
Serial.println("DHCP config failed! ");
}
Serial.print("NTP Server: ");
Serial.println(timeServer);

setSyncInterval(5); // Set seconds between re-sync (5s for test only)
Udp.begin(localPort);
}

void loop() {
setSyncProvider(getNtpTime);
digitalClockDisplay();
delay(1000);
}

void digitalClockDisplay(){
// digital clock display of the time
Serial.print(day());
Serial.print(".");
Serial.print(month());
Serial.print(".");
Serial.print(year());
Serial.print(" ");
Serial.print(hour());
printDigits(minute());
printDigits(second());
Serial.println(" ");
}

void printDigits(int digits){
// utility function for digital clock display: prints preceding
// colon and leading 0
Serial.print(":");
if(digits < 10)
Serial.print('0');
Serial.print(digits);
}

/*-------- NTP code ----------*/

unsigned long getNtpTime()
{
sendNTPpacket(timeServer); // send an NTP packet to a time server
delay(500);

if ( Udp.parsePacket() ) {
Udp.read(packetBuffer,NTP_PACKET_SIZE); // read packet into buffer

//the timestamp starts at byte 40, convert four bytes into a long integer
unsigned long hi = word(packetBuffer[40], packetBuffer[41]);
unsigned long low = word(packetBuffer[42], packetBuffer[43]);
// this is NTP time (seconds since Jan 1 1900
unsigned long secsSince1900 = hi << 16 | low;
// Unix time starts on Jan 1 1970
const unsigned long seventyYears = 2208988800UL;
unsigned long epoch = secsSince1900 - seventyYears; // subtract 70 years, add Daylight Saving and Timezone adjust
return epoch;
}
return 0; // return 0 if unable to get the time
}

// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address)
//sendNTPpacket(IPAddress address)
{
memset(packetBuffer, 0, NTP_PACKET_SIZE); // set all bytes in the buffer to 0

// Initialize values needed to form NTP request
packetBuffer[0] = B11100011; // LI, Version, Mode
packetBuffer[1] = 0; // Stratum
packetBuffer[2] = 6; // Max Interval between messages in seconds
packetBuffer[3] = 0xEC; // Clock Precision
// bytes 4 - 11 are for Root Delay and Dispersion and were set to 0 by memset
packetBuffer[12] = 49; // four-byte reference ID identifying
packetBuffer[13] = 0x4E;
packetBuffer[14] = 49;
packetBuffer[15] = 52;

// send the packet requesting a timestamp:
Udp.beginPacket(address, 123); //NTP requests are to port 123
Udp.write(packetBuffer,NTP_PACKET_SIZE);
Udp.endPacket();
}

@@ Line 1: / Line 1: @@
 ==Code==
+ // time ntp sync
   #include <Time.h>
   #include <SPI.h>
@@ Line 11: / Line 12: @@
   // Ethernet library configuration
   byte mac[] = { 0x24, 0x7B, 0xA2, 0x4A, 0x52, 0x10 };
-  IPAddress timeServer(128, 138, 140, 44 ); // time.nist.gov
+  IPAddress timeServer(128, 138, 140, 44 );
   unsigned int localPort = 8888;
   const int NTP_PACKET_SIZE= 48;
   byte packetBuffer[NTP_PACKET_SIZE];
   EthernetUDP Udp;
-−
   void setup() {
@@ Line 32: / Line 32: @@
     Serial.println(timeServer);
     setSyncInterval(5); // Set seconds between re-sync (5s for test only)
     Udp.begin(localPort);
+  }
-−
   void loop() {
     digitalClockDisplay();
-   delay(1000);
   void digitalClockDisplay(){
@@ Line 69: / Line 75: @@
   unsigned long getNtpTime()
+  {
-   sendNTPpacket(timeServer); // send an NTP packet to a time server
+    sendNTPpacket(timeServer); // send an NTP packet to a time server
-     delay(500);
+      delay(500);
-−
-     if ( Udp.parsePacket() ) {
+      if ( Udp.parsePacket() ) {
-      Udp.read(packetBuffer,NTP_PACKET_SIZE);  // read packet into buffer
+        Udp.read(packetBuffer,NTP_PACKET_SIZE);  // read packet into buffer
-−
        //the timestamp starts at byte 40, convert four bytes into a long integer
        unsigned long hi = word(packetBuffer[40], packetBuffer[41]);
@@ Line 92: / Line 98: @@
   //sendNTPpacket(IPAddress address)
+  {
     memset(packetBuffer, 0, NTP_PACKET_SIZE);  // set all bytes in the buffer to 0
     // Initialize values needed to form NTP request