arduino stuffs
Diffstat (limited to 'libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.ino')
| -rw-r--r-- | libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.ino | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.ino b/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.ino new file mode 100644 index 0000000..ec52717 --- /dev/null +++ b/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.ino @@ -0,0 +1,156 @@ +/* + + Udp NTP Client + + Get the time from a Network Time Protocol (NTP) time server + Demonstrates use of UDP sendPacket and ReceivePacket + For more on NTP time servers and the messages needed to communicate with them, + see http://en.wikipedia.org/wiki/Network_Time_Protocol + + created 4 Sep 2010 + by Michael Margolis + modified 9 Apr 2012 + by Tom Igoe + modified 02 Sept 2015 + by Arturo Guadalupi + + This code is in the public domain. + + */ + +#include <SPI.h> +#include <Ethernet.h> +#include <EthernetUdp.h> + +// Enter a MAC address for your controller below. +// Newer Ethernet shields have a MAC address printed on a sticker on the shield +byte mac[] = { + 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED +}; + +unsigned int localPort = 8888; // local port to listen for UDP packets + +const char timeServer[] = "time.nist.gov"; // time.nist.gov NTP server + +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 + +// A UDP instance to let us send and receive packets over UDP +EthernetUDP Udp; + +void setup() { + // 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 + + // Open serial communications and wait for port to open: + Serial.begin(9600); + while (!Serial) { + ; // wait for serial port to connect. Needed for native USB port only + } + + // start Ethernet and UDP + if (Ethernet.begin(mac) == 0) { + Serial.println("Failed to configure Ethernet using DHCP"); + // Check for Ethernet hardware present + if (Ethernet.hardwareStatus() == EthernetNoHardware) { + Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :("); + } else if (Ethernet.linkStatus() == LinkOFF) { + Serial.println("Ethernet cable is not connected."); + } + // no point in carrying on, so do nothing forevermore: + while (true) { + delay(1); + } + } + Udp.begin(localPort); +} + +void loop() { + sendNTPpacket(timeServer); // send an NTP packet to a time server + + // wait to see if a reply is available + delay(1000); + 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, extract 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; + Serial.print("Seconds since Jan 1 1900 = "); + Serial.println(secsSince1900); + + // now convert NTP time into everyday time: + Serial.print("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: + Serial.println(epoch); + + + // print the hour, minute and second: + Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT) + Serial.print((epoch % 86400L) / 3600); // print the hour (86400 equals secs per day) + Serial.print(':'); + if (((epoch % 3600) / 60) < 10) { + // In the first 10 minutes of each hour, we'll want a leading '0' + Serial.print('0'); + } + Serial.print((epoch % 3600) / 60); // print the minute (3600 equals secs per minute) + Serial.print(':'); + if ((epoch % 60) < 10) { + // In the first 10 seconds of each minute, we'll want a leading '0' + Serial.print('0'); + } + Serial.println(epoch % 60); // print the second + } + // wait ten seconds before asking for the time again + delay(10000); + Ethernet.maintain(); +} + +// send an NTP request to the time server at the given address +void sendNTPpacket(const char * 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[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(address, 123); // NTP requests are to port 123 + Udp.write(packetBuffer, NTP_PACKET_SIZE); + Udp.endPacket(); +} + + + + + + + + + + |