[新手] arduino通过ntp服务器同步时间
用的板子是DFRobot的MEGA2560+W5100 Ethernet，参考arduino.cc上的例程做的。仅仅是测试。http://v.youku.com/v_show/id_XNzE1NDc5MTY0.html 有代码么？特别是NTP方面的 在后面我又加了GPS对时功能，都仅仅是测试，只有时间校准，没有日期校准。
2脚接地开机为网络对时，使用苹果的时间服务器，8脚接地为gps对时，gps模块接在mega 2560的serial1串口上，波特率为38400，NMEA标准码。
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
#include "Dns.h"
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include "DS3231.h"
#include <TinyGPS.h>
byte mac[] = {0x00, 0x00, 0xAA, 0xBB, 0xCC, 0xDD};
unsigned int localPort = 80; // local port to listen for UDP packets
IPAddress timeServer(193, 92, 150, 3); // time.nist.gov NTP server (fallback)
const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message
byte packetBuffer[ NTP_PACKET_SIZE]; // buffer to hold incoming and outgoing packets
const char* host = "time.asia.apple.com"; // Use random servers through DNS
EthernetUDP Udp;
DNSClient Dns;
IPAddress rem_add;
TinyGPS gps;
LiquidCrystal_I2C lcd(0x27, 16, 2);
DS3231 clock;
bool Century = false, h12 = false, PM = false;
int year;
byte month, date, day, hour, minute, second, temperature, hundredths;
unsigned long age = 0;
char timeStr, dateStr;
void setup()
{
Wire.begin();
Serial.begin(9600);
Serial1.begin(38400);
pinMode(4, OUTPUT);
digitalWrite(4, HIGH);
pinMode(8, INPUT_PULLUP);
pinMode(2, INPUT_PULLUP);
lcd.init();
lcd.backlight();
lcd.clear();
if (digitalRead(2) == 0)
{
lcd.setCursor(0, 0);
lcd.print("WAITING DHCP SRV");
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
lcd.setCursor(0, 1);
lcd.print("DHCP SRV FAILED");
delay(2000);
lcd.clear();
return;
}
Udp.begin(localPort);
Dns.begin(Ethernet.dnsServerIP() );
lcd.setCursor(0, 1);
lcd.print("NETWORK OK!");
delay(1000);
lcd.clear();
ntpTime();
clock.setSecond(second);
clock.setHour(hour);
clock.setMinute(minute);
lcd.print("NET TIME SYNC OK!");
snprintf(timeStr, 17, "NET: %02d:%02d:%02d", hour, minute, second);
lcd.setCursor(0, 1);
lcd.print(timeStr);
delay(2000);
lcd.clear();
}
else
{ lcd.setCursor(0, 1);
lcd.print("NET TIME BYPASS");
delay(2000);
lcd.clear();
}
if (digitalRead(8) == 0)
{
int timeout = 0;
lcd.setCursor(0, 0);
lcd.print("GPS TIME SYNC..");
do
{
timeout += 1;
smartdelay(250);
gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age );
}
while (age == TinyGPS::GPS_INVALID_AGE);
if (age != TinyGPS::GPS_INVALID_AGE)
{
hour+=8;
if (hour > 23)
{
hour -= 24;
}
delay(400);
second+=1;
clock.setSecond(second);
clock.setHour(hour);
clock.setMinute(minute);
lcd.setCursor(0, 0);
lcd.print("GPS TIME OK! ");
snprintf(timeStr, 17, "GPS: %02d:%02d:%02d", hour, minute, second);
lcd.setCursor(0, 1);
lcd.print(timeStr);
delay(2000);
lcd.clear();
}
else
{
lcd.setCursor(0, 0);
lcd.print("GPS TIME FAILED");
delay(2000);
lcd.clear();
}
}
else
{
lcd.setCursor(0, 1);
lcd.print("GPS TIME BYPASS");
delay(2000);
lcd.clear();
}
}
void loop()
{
hour = clock.getHour(h12, PM);
minute = clock.getMinute();
second = clock.getSecond();
snprintf(timeStr, 17, "DS3231: %02d:%02d:%02d", hour, minute, second);
//snprintf(dateStr,8,"%4d-%02d-%02d",year,month,date);
lcd.setCursor(0, 0);
lcd.print(timeStr);
delay(50);
}
void ntpTime()
{
if (Dns.getHostByName(host, rem_add) == 1 ) {
Serial.print("DNS resolve : ");
Serial.print(host);
Serial.print("= ");
Serial.print(rem_add);
sendNTPpacket(rem_add);
} else {
Serial.print("DNS fail...");
Serial.print("time.nist.gov = ");
Serial.print(timeServer); // fallback
sendNTPpacket(timeServer); // send an NTP packet to a time server
}
delay(300); // wait to see if a reply is available
if ( Udp.parsePacket() ) {
// We've received a packet, read the data from it
Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer
//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, packetBuffer);
unsigned long lowWord = word(packetBuffer, packetBuffer);
// 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;
Serial.print("NTP Time Stamp: ");
Serial.print(secsSince1900);
// now convert NTP time into everyday time:
Serial.print(" Unix Epoch time = ");
// Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
const unsigned long seventyYears = 2208988800UL;
// subtract seventy years:
delay(200);
unsigned long epoch = secsSince1900 - seventyYears;
epoch += 1;
// print Unix time:
Serial.print(epoch);
Serial.print(" ");
// print the hour, minute and second: local time +8:00
hour = (epoch % 86400L) / 3600 + 8;
if (hour > 23)
{
hour -= 24;
}
minute = (epoch % 3600) / 60;
second = epoch % 60;
}
}
// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address)
{
// 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 = 0b11100011; // LI, Version, Mode
packetBuffer = 0; // Stratum, or type of clock
packetBuffer = 6; // Polling Interval
packetBuffer = 0xEC;// Peer Clock Precision
// 8 bytes of zero for Root Delay & Root Dispersion
packetBuffer = 49;
packetBuffer = 0x4E;
packetBuffer = 49;
packetBuffer = 52;
// all NTP fields have been given values, now
// you can send a packet requesting a timestamp:
Udp.beginPacket(address, 123); //NTP requests are to port 123
Udp.write(packetBuffer, NTP_PACKET_SIZE);
Udp.endPacket();
}
static void smartdelay(unsigned long ms)
{
unsigned long start = millis();
do
{
while (Serial1.available())
gps.encode(Serial1.read());
} while (millis() - start < ms);
} 都是example里面代码，再加了一些lcd1602的代码编辑的，tinyGPS库非常好用。 初学者学习 为啥我的没有接收到ntp的信息那
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