Initial commit

Timestamps.cpp

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+/*
+ Timestamps.cpp - Library for getting both UNIX and NTP timestamps.
+ Created by Stefan Herzog, April 16 2020.
+ Released into the public domain.
+*/
+
+#include "Arduino.h"
+#include "Timestamps.h"
+
+Timestamps::Timestamps(int timeZoneOffset=0) {
+ _timeZoneOffset = timeZoneOffset;
+}
+
+bool Timestamps::isLeapYear(unsigned int year) {
+if (year % 4 == 0) {
+ if (year % 100 == 0) {
+ if (year % 400 == 0) {
+ return true;
+ }
+ else {
+ return false;
+ }
+ }
+ else {
+ return true;
+ }
+}
+else {
+ return false;
+}
+}
+
+unsigned int Timestamps::getTimestamp(int referenceYear, int year, int month, int day, int hour, int minute, int second, int timeZoneOffset=0) {
+ unsigned int timestamp=0;
+ // Either use the time zone offset value from instantiating or the given paramter
+ /*
+ 1. _timeZoneOffset is set AND timeZoneOffset is set -> use timeZoneOffset
+ 2. _timeZoneOffset is set AND timeZoneOffset is NOT set -> use _timeZoneOffset
+ 3. _timeZoneOffset is NOT set AND timeZoneOffset is set -> use timeZoneOffset
+ 4. _timeZoneOffset is NOT set AND timeZoneOffset is NOT set -> use timeZoneOffset
+ */
+ if(_timeZoneOffset != 0 && timeZoneOffset != 0) {
+ timeZoneOffset = timeZoneOffset;
+ }
+ else if(_timeZoneOffset != 0 && timeZoneOffset == 0) {
+ timeZoneOffset = _timeZoneOffset;
+ }
+ else if(_timeZoneOffset == 0 && timeZoneOffset != 0) {
+ timeZoneOffset = _timeZoneOffset;
+ }
+ else if(_timeZoneOffset == 0 && timeZoneOffset == 0) {
+ timeZoneOffset = timeZoneOffset;
+ }
+ else {
+ // ERROR
+ }
+
+ timestamp += timeZoneOffset;
+
+ day <= 0 ? day=0 : day=day-1;
+ hour <= 0 ? hour=0 : hour=hour-1;
+
+ for(int y=referenceYear; y<year; y++) {
+ timestamp += 365*secondsPerDay;
+
+ if(isLeapYear(y)) {
+ // Year is leap year -> add one day to timestamp
+ timestamp += secondsPerDay;
+ }
+ }
+
+ for(int m=1; m<=month; m++) {
+ if(month == 1) {
+ // we're still in January
+ timestamp += day * secondsPerDay; // time until yesterday evening / tonight 0:00
+ timestamp += hour * secondsPerHour;
+ timestamp += minute*60;
+ timestamp += second;
+ }
+ if(month > 1) {
+ timestamp += daysPerMonth[m-1] * secondsPerDay; // last month
+
+ timestamp += day * secondsPerDay; // time until yesterday evening / tonight 0:00
+ timestamp += hour * secondsPerHour;
+ timestamp += minute*60;
+ timestamp += second;
+
+ if(isLeapYear(year) == 0 && month == 3) {
+ // current year is leap year, so 29.02. exists
+ // Since we're in March now, add the 29.02. to the timestamp
+ timestamp += secondsPerDay; // 29.02.
+ }
+ }
+ }
+ return timestamp;
+}
+
+unsigned int Timestamps::getTimestampUNIX(int year, int month, int day, int hour, int minute, int second, int timeZoneOffset=0) {
+return getTimestamp(1970, year, month, day, hour, minute, second, timeZoneOffset);
+}
+
+unsigned int Timestamps::getTimestampNTP(int year, int month, int day, int hour, int minute, int second, int timeZoneOffset=0) {
+return getTimestamp(1900, year, month, day, hour, minute, second, timeZoneOffset);
+}
+
+int Timestamps::secondsPerHour = 60*60;
+int Timestamps::secondsPerDay = 24 * secondsPerHour;
+int Timestamps::daysPerMonth[12] = {31,28,31,30,31,30,31,31,30,31,30,31};

Timestamps.h

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+#ifndef timestamps_h
+#define timestamps_h
+
+#include "Arduino.h"
+
+class Timestamps {
+ public:
+ Timestamps(int setTimeZoneOffset);
+ unsigned int getTimestampUNIX(int year, int month, int day, int hour, int minute, int second, int setTimeZoneOffset);
+ unsigned int getTimestampNTP(int year, int month, int day, int hour, int minute, int second, int setTimeZoneOffset);
+ bool isLeapYear(unsigned int year);
+ private:
+ unsigned int getTimestamp(int referenceYear, int year, int month, int day, int hour, int minute, int second, int setTimeZoneOffset);
+ static int secondsPerHour;
+ static int secondsPerDay;
+ static int daysPerMonth[12];
+ int _timeZoneOffset;
+ };
+
+#endif

examples/getTimestamps.ino

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+/*
+Here's an example of how to generate two timestamps:
+1. UNIX-timestamp: Used by most clients like servers etc.
+2. NTP-timestamp: Can be retrieved by network-shields and calls to a NTP server
+*/
+
+#include <Timestamps.h>
+
+Timestamps ts(3600); // instantiating object of class Timestamp with an time offset of 3.600 seconds for Western Eurpean Time
+
+void setup() {
+ Serial.begin(115200);
+ while(!Serial) {
+ // While serial port is not ready yet, wait a time for it
+ delay(100);
+ }
+}
+
+void loop() {
+ Serial.print("UNIX timestamp: ");
+ // Get the timestamp for the given date (11. January 2020) and time (14:30:20)
+ Serial.println(getTimestampUNIX(2020, 1, 25, 14, 30, 20)); // returns: 1579962620 (remember the given offset of 3600 seconds in line 9)
+
+ Serial.print("UNIX timestamp without offset: ");
+ // You can also use a specified time offset, here "0" as last parameter
+ Serial.println(getTimestampUNIX(2020, 1, 25, 14, 30, 20, 0)); // returns: 1579959020 (notice the given offset of 0 [last parameter])
+
+ Serial.print("NTP timestamp: ");
+ Serial.println(getTimestampNTP(2020, 1, 25, 14, 30, 20)); // returns: 3788951420 (remember the given offset of 3600 seconds in line 9)
+}

keywords.txt

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+Timestamps KEYWORD1
+getTimestampUNIX KEYWORD2
+getTimestampNTP KEYWORD2