Difference between revisions of "Arduino: RTC DS3231 NTP Sync"
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Onnowpurbo (talk | contribs) (Created page with "==Source== #include "Wire.h" #include <Time.h> #include <SPI.h> #include <Ethernet.h> #include <EthernetUdp.h> #define DS3231_I2C_ADDRESS 0x68 // Ethernet library configur...") |
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− | #include "Wire.h" | + | #include "Wire.h" |
− | #include <Time.h> | + | #include <Time.h> |
− | #include <SPI.h> | + | #include <SPI.h> |
− | #include <Ethernet.h> | + | #include <Ethernet.h> |
− | #include <EthernetUdp.h> | + | #include <EthernetUdp.h> |
− | + | ||
− | #define DS3231_I2C_ADDRESS 0x68 | + | #define DS3231_I2C_ADDRESS 0x68 |
− | + | ||
− | // Ethernet library configuration | + | // Ethernet library configuration |
− | byte mac[] = { 0x24, 0x7B, 0xA2, 0x4A, 0x52, 0x10 }; | + | byte mac[] = { 0x24, 0x7B, 0xA2, 0x4A, 0x52, 0x10 }; |
− | IPAddress timeServer(128, 138, 140, 44 ); // time.nist.gov | + | IPAddress timeServer(128, 138, 140, 44 ); // time.nist.gov |
− | + | ||
− | unsigned int localPort = 8888; | + | unsigned int localPort = 8888; |
− | const int NTP_PACKET_SIZE= 48; | + | const int NTP_PACKET_SIZE= 48; |
− | byte packetBuffer[NTP_PACKET_SIZE]; | + | byte packetBuffer[NTP_PACKET_SIZE]; |
− | EthernetUDP Udp; | + | EthernetUDP Udp; |
− | + | ||
− | void setup() | + | void setup() |
− | { | + | { |
− | + | // Setup Communication | |
− | + | Wire.begin(); | |
− | + | Serial.begin(9600); | |
− | + | Serial.print("OK Serial\n"); | |
− | + | Ethernet.begin(mac); | |
− | + | Serial.print("OK LAN\n"); | |
− | + | Udp.begin(localPort); | |
− | + | ||
− | + | Serial.print("OK Comm\n"); | |
− | + | setSyncInterval(10); // Set seconds between re-sync | |
− | + | setSyncProvider(getNtpTime); | |
− | + | getNtpTime; | |
− | + | Serial.print("OK NTP\n"); | |
− | + | ||
− | + | // set the initial time here: | |
− | + | // DS3231 seconds, minutes, hours, day, date, month, year | |
− | + | // setDS3231time(30,33,9, 2 ,28,11,16); | |
− | } | + | } |
− | + | ||
− | void loop() | + | void loop() |
− | { | + | { |
− | + | setSyncProvider(getNtpTime); | |
− | + | // set the initial time here: | |
− | + | // DS3231 seconds, minutes, hours, day, date, month, year | |
− | + | setDS3231time(second(), minute(), hour()+7, 5 , 7, 6, 18); | |
− | + | ||
− | + | displayTime(); // display the real-time clock data on the Serial Monitor, | |
− | + | getNtpTime; | |
− | + | // delay(1000); | |
− | } | + | } |
− | + | ||
− | + | /*----------------- DS3231 ----------------------*/ | |
− | + | ||
− | /*----------------- DS3231 ----------------------*/ | + | // Convert normal decimal numbers to binary coded decimal |
− | + | byte decToBcd(byte val) | |
− | // Convert normal decimal numbers to binary coded decimal | + | { |
− | byte decToBcd(byte val) | + | return ( (val / 10 * 16) + (val % 10) ); |
− | { | + | } |
− | + | // Convert binary coded decimal to normal decimal numbers | |
− | } | + | byte bcdToDec(byte val) |
− | // Convert binary coded decimal to normal decimal numbers | + | { |
− | byte bcdToDec(byte val) | + | return ( (val / 16 * 10) + (val % 16) ); |
− | { | + | } |
− | + | ||
− | } | + | void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte |
− | + | dayOfMonth, byte month, byte year) | |
− | void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte | + | { |
− | + | // sets time and date data to DS3231 | |
− | { | + | Wire.beginTransmission(DS3231_I2C_ADDRESS); |
− | + | Wire.write(0); // set next input to start at the seconds register | |
− | + | Wire.write(decToBcd(second)); // set seconds | |
− | + | Wire.write(decToBcd(minute)); // set minutes | |
− | + | Wire.write(decToBcd(hour)); // set hours | |
− | + | Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday) | |
− | + | Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31) | |
− | + | Wire.write(decToBcd(month)); // set month | |
− | + | Wire.write(decToBcd(year)); // set year (0 to 99) | |
− | + | Wire.endTransmission(); | |
− | + | } | |
− | + | void readDS3231time(byte *second, | |
− | } | + | byte *minute, |
− | void readDS3231time(byte *second, | + | byte *hour, |
− | + | byte *dayOfWeek, | |
− | + | byte *dayOfMonth, | |
− | + | byte *month, | |
− | + | byte *year) | |
− | + | { | |
− | + | Wire.beginTransmission(DS3231_I2C_ADDRESS); | |
− | { | + | Wire.write(0); // set DS3231 register pointer to 00h |
− | + | Wire.endTransmission(); | |
− | + | Wire.requestFrom(DS3231_I2C_ADDRESS, 7); | |
− | + | // request seven bytes of data from DS3231 starting from register 00h | |
− | + | *second = bcdToDec(Wire.read() & 0x7f); | |
− | + | *minute = bcdToDec(Wire.read()); | |
− | + | *hour = bcdToDec(Wire.read() & 0x3f); | |
− | + | *dayOfWeek = bcdToDec(Wire.read()); | |
− | + | *dayOfMonth = bcdToDec(Wire.read()); | |
− | + | *month = bcdToDec(Wire.read()); | |
− | + | *year = bcdToDec(Wire.read()); | |
− | + | } | |
− | + | void displayTime() | |
− | } | + | { |
− | void displayTime() | + | byte second, minute, hour, dayOfWeek, dayOfMonth, month, year; |
− | { | + | // retrieve data from DS3231 |
− | + | readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, | |
− | + | &year); | |
− | + | // send it to the serial monitor | |
− | + | Serial.print(hour, DEC); | |
− | + | // convert the byte variable to a decimal number when displayed | |
− | + | Serial.print(":"); | |
− | + | if (minute < 10) | |
− | + | { | |
− | + | Serial.print("0"); | |
− | + | } | |
− | + | Serial.print(minute, DEC); | |
− | + | Serial.print(":"); | |
− | + | if (second < 10) | |
− | + | { | |
− | + | Serial.print("0"); | |
− | + | } | |
− | + | Serial.print(second, DEC); | |
− | + | Serial.print(" "); | |
− | + | Serial.print(dayOfMonth, DEC); | |
− | + | Serial.print("/"); | |
− | + | Serial.print(month, DEC); | |
− | + | Serial.print("/"); | |
− | + | Serial.print(year, DEC); | |
− | + | Serial.print(" Day of week: "); | |
− | + | switch (dayOfWeek) { | |
− | + | case 1: | |
− | + | Serial.println("Sunday"); | |
− | + | break; | |
− | + | case 2: | |
− | + | Serial.println("Monday"); | |
− | + | break; | |
− | + | case 3: | |
− | + | Serial.println("Tuesday"); | |
− | + | break; | |
− | + | case 4: | |
− | + | Serial.println("Wednesday"); | |
− | + | break; | |
− | + | case 5: | |
− | + | Serial.println("Thursday"); | |
− | + | break; | |
− | + | case 6: | |
− | + | Serial.println("Friday"); | |
− | + | break; | |
− | + | case 7: | |
− | + | Serial.println("Saturday"); | |
− | + | break; | |
− | + | } | |
− | + | } | |
− | + | ||
− | } | + | |
− | + | /*-------- NTP code ----------*/ | |
− | + | ||
− | + | unsigned long getNtpTime() | |
− | + | { | |
− | /*-------- NTP code ----------*/ | + | sendNTPpacket(timeServer); // send an NTP packet to a time server |
− | + | delay(500); | |
− | unsigned long getNtpTime() | + | |
− | { | + | if ( Udp.parsePacket() ) { |
− | + | Udp.read(packetBuffer,NTP_PACKET_SIZE); | |
− | + | unsigned long hi = word(packetBuffer[40], packetBuffer[41]); | |
− | + | unsigned long low = word(packetBuffer[42], packetBuffer[43]); | |
− | + | unsigned long secsSince1900 = hi << 16 | low; | |
− | + | const unsigned long seventyYears = 2208988800UL; | |
− | + | unsigned long epoch = secsSince1900 - seventyYears; | |
− | + | return epoch; | |
− | + | } | |
− | + | return 0; // return 0 if unable to get the time | |
− | + | } | |
− | + | ||
− | + | unsigned long sendNTPpacket(IPAddress& address) | |
− | + | { | |
− | } | + | memset(packetBuffer, 0, NTP_PACKET_SIZE); // set all bytes in the buffer to 0 |
− | + | ||
− | unsigned long sendNTPpacket(IPAddress& address) | + | // 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(); | |
− | + | } | |
− | |||
− | |||
− | |||
− | } |
Latest revision as of 07:56, 7 June 2018
Source
#include "Wire.h" #include <Time.h> #include <SPI.h> #include <Ethernet.h> #include <EthernetUdp.h> #define DS3231_I2C_ADDRESS 0x68 // Ethernet library configuration byte mac[] = { 0x24, 0x7B, 0xA2, 0x4A, 0x52, 0x10 }; IPAddress timeServer(128, 138, 140, 44 ); // time.nist.gov unsigned int localPort = 8888; const int NTP_PACKET_SIZE= 48; byte packetBuffer[NTP_PACKET_SIZE]; EthernetUDP Udp; void setup() { // Setup Communication Wire.begin(); Serial.begin(9600); Serial.print("OK Serial\n"); Ethernet.begin(mac); Serial.print("OK LAN\n"); Udp.begin(localPort); Serial.print("OK Comm\n"); setSyncInterval(10); // Set seconds between re-sync setSyncProvider(getNtpTime); getNtpTime; Serial.print("OK NTP\n"); // set the initial time here: // DS3231 seconds, minutes, hours, day, date, month, year // setDS3231time(30,33,9, 2 ,28,11,16); } void loop() { setSyncProvider(getNtpTime); // set the initial time here: // DS3231 seconds, minutes, hours, day, date, month, year setDS3231time(second(), minute(), hour()+7, 5 , 7, 6, 18); displayTime(); // display the real-time clock data on the Serial Monitor, getNtpTime; // delay(1000); } /*----------------- DS3231 ----------------------*/ // Convert normal decimal numbers to binary coded decimal byte decToBcd(byte val) { return ( (val / 10 * 16) + (val % 10) ); } // Convert binary coded decimal to normal decimal numbers byte bcdToDec(byte val) { return ( (val / 16 * 10) + (val % 16) ); } void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte dayOfMonth, byte month, byte year) { // sets time and date data to DS3231 Wire.beginTransmission(DS3231_I2C_ADDRESS); Wire.write(0); // set next input to start at the seconds register Wire.write(decToBcd(second)); // set seconds Wire.write(decToBcd(minute)); // set minutes Wire.write(decToBcd(hour)); // set hours Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday) Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31) Wire.write(decToBcd(month)); // set month Wire.write(decToBcd(year)); // set year (0 to 99) Wire.endTransmission(); } void readDS3231time(byte *second, byte *minute, byte *hour, byte *dayOfWeek, byte *dayOfMonth, byte *month, byte *year) { Wire.beginTransmission(DS3231_I2C_ADDRESS); Wire.write(0); // set DS3231 register pointer to 00h Wire.endTransmission(); Wire.requestFrom(DS3231_I2C_ADDRESS, 7); // request seven bytes of data from DS3231 starting from register 00h *second = bcdToDec(Wire.read() & 0x7f); *minute = bcdToDec(Wire.read()); *hour = bcdToDec(Wire.read() & 0x3f); *dayOfWeek = bcdToDec(Wire.read()); *dayOfMonth = bcdToDec(Wire.read()); *month = bcdToDec(Wire.read()); *year = bcdToDec(Wire.read()); } void displayTime() { byte second, minute, hour, dayOfWeek, dayOfMonth, month, year; // retrieve data from DS3231 readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year); // send it to the serial monitor Serial.print(hour, DEC); // convert the byte variable to a decimal number when displayed Serial.print(":"); if (minute < 10) { Serial.print("0"); } Serial.print(minute, DEC); Serial.print(":"); if (second < 10) { Serial.print("0"); } Serial.print(second, DEC); Serial.print(" "); Serial.print(dayOfMonth, DEC); Serial.print("/"); Serial.print(month, DEC); Serial.print("/"); Serial.print(year, DEC); Serial.print(" Day of week: "); switch (dayOfWeek) { case 1: Serial.println("Sunday"); break; case 2: Serial.println("Monday"); break; case 3: Serial.println("Tuesday"); break; case 4: Serial.println("Wednesday"); break; case 5: Serial.println("Thursday"); break; case 6: Serial.println("Friday"); break; case 7: Serial.println("Saturday"); break; } } /*-------- 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); unsigned long hi = word(packetBuffer[40], packetBuffer[41]); unsigned long low = word(packetBuffer[42], packetBuffer[43]); unsigned long secsSince1900 = hi << 16 | low; const unsigned long seventyYears = 2208988800UL; unsigned long epoch = secsSince1900 - seventyYears; return epoch; } return 0; // return 0 if unable to get the time } unsigned long 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(); }