Functions to convert between TimeLib and time.h time representations.

ConvertTime.h

@@ -0,0 +1,41 @@
+/*
+  ConvertTime.h - convert time representations between TimeLib's and sdtlib <time.h>'s
+*/
+
+#ifndef _ConvertTime_h
+#define _ConvertTime_h
+
+#include <time.h>
+#include <TimeLib.h>
+//fortunately TimeLib and time.h's definitions of time_t are both unsigned 32 bit, otherwise there might be trouble.
+
+//converts TimeLib's time representations to time.h's representations
+inline void convertToTimeH(tmElements_t &timelib, tm &timeh){
+  time_t t = makeTime(timelib) - UNIX_OFFSET;
+  localtime_r(&t, &timeh);
+}
+inline void convertToTimeH(time_t timelib, tm &timeh){
+  time_t t = timelib - UNIX_OFFSET;
+  localtime_r(&t, &timeh);
+}
+inline time_t convertToTimeH(tmElements_t &timelib){
+  return makeTime(timelib) - UNIX_OFFSET;
+}
+inline time_t convertToTimeH(time_t timelib){
+  return timelib - UNIX_OFFSET;
+}
+
+//converts time.h's time representations to TimeLib's representations
+inline void convertToTimeLib(tm &timeh, tmElements_t &timelib){
+  breakTime(mktime(&timeh) + UNIX_OFFSET, timelib);
+}
+inline void convertToTimeLib(time_t timeh, tmElements_t &timelib){
+  breakTime(timeh + UNIX_OFFSET, timelib);
+}
+inline time_t convertToTimeLib(tm &timeh){
+  return mktime(&timeh) + UNIX_OFFSET;
+}
+inline time_t convertToTimeLib(time_t timeh){
+  return timeh + UNIX_OFFSET;
+}
+#endif _ConvertTime_h

examples/TimeConversion/TimeConversion.ino

@@ -0,0 +1,98 @@
+/* 
+ * TimeConversion.ino
+ *
+ * This program demonstrates one way to use the time conversion <ConvertTime.h> part of the library, 
+ * to allow you to easily handle timezones and daylight savings time, and make printing much simpler.
+ * 
+ * To customize the timezone, edit the UTC_OFFSET value. 
+ * To enable automatic daylight saving time calculations, uncomment the corresponding daylight 
+ * savings blocks.
+ * 
+ * This uses the same code as the TimeSerial example to synchronize the time.
+ * A Processing example sketch to automatically send the messages is included in the download
+ * On Linux, you can use "date +T%s\n > /dev/ttyACM0" (UTC time zone)
+ */ 
+
+
+// change this to the UTC offset of the timezone you want:
+// for reference here are the USA offset values:
+// PST = -8, MST = -7, CST = -6, EST = -5
+#define UTC_OFFSET -7 
+
+// Uncomment one of these blocks to enable daylight savings time calculations:
+// For USA daylight savings:
+
+//#include <util/usa_dst.h>
+//#define DST usa_dst;
+
+// For european daylight savings:
+
+//#include <util/eur_dst.h>
+//#define DST eur_dst;
+
+
+
+
+#include <time.h>
+
+#include <Time.h>
+#include <ConvertTime.h>
+
+
+void setup() {
+  Serial.begin(9600);
+  while (!Serial) ; // Needed for Leonardo only
+
+  Serial.println("Waiting for sync message");
+
+  #ifdef DST // set daylight savings if configured.
+  set_dst(DST);
+  #endif
+
+  set_zone(UTC_OFFSET * SECS_PER_HOUR); //set timezone offset
+
+}
+
+void loop() {
+  // Serial clock synchronization routine. See the TimeSerial example for an explanation of how this works.
+  if (Serial.available()) {
+    processSyncMessage();
+  }
+
+  if (timeStatus()!= timeNotSet) {
+    digitalClockDisplay();  
+  }
+
+  delay(1000);
+}
+
+
+void digitalClockDisplay() {
+  time_t libtime = now(); // get the current time according to LibTime.
+  time_t timeh = convertToTimeH(libtime); // time.h uses a different format, so have to convert.
+  String str = ctime(&timeh); // but once we have it there, it only takes one line to turn it into a string.
+  // You can also easily do custom time formats using the 'strftime', although it's a bit more complicated to use.
+  Serial.println(str); // and print that time.
+}
+
+
+
+#define TIME_HEADER  "T"   // Header tag for serial time sync message
+
+// Serial clock synchronization routine. See the TimeSerial example to see how this works.
+void processSyncMessage() { 
+  unsigned long pctime;
+  const unsigned long DEFAULT_TIME = 1357041600; // Jan 1 2013
+
+  if(Serial.find(TIME_HEADER)) {
+     pctime = Serial.parseInt();
+     if( pctime >= DEFAULT_TIME) { // check the integer is a valid time (greater than Jan 1 2013)
+       setTime(pctime); // Sync Arduino clock to the time received on the serial port
+     }
+  }
+}
+
+
+
+
+

keywords.txt

@@ -25,6 +25,8 @@ setSyncProvider	KEYWORD2
 setSyncInterval	KEYWORD2
 timeStatus	KEYWORD2
 TimeLib	KEYWORD2
+convertToTimeLib	KEYWORD2
+convertToTimeH	KEYWORD2
 #######################################
 # Instances (KEYWORD2)
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