summaryrefslogtreecommitdiff
path: root/Time/Time.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'Time/Time.cpp')
-rw-r--r--Time/Time.cpp307
1 files changed, 307 insertions, 0 deletions
diff --git a/Time/Time.cpp b/Time/Time.cpp
new file mode 100644
index 0000000..86bdcd5
--- /dev/null
+++ b/Time/Time.cpp
@@ -0,0 +1,307 @@
+/*
+ time.c - low level time and date functions
+ Copyright (c) Michael Margolis 2009
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+ 6 Jan 2010 - initial release
+ 12 Feb 2010 - fixed leap year calculation error
+ 1 Nov 2010 - fixed setTime bug (thanks to Korman for this)
+*/
+
+#if ARDUINO >= 100
+#include <Arduino.h>
+#else
+#include <WProgram.h>
+#endif
+
+#include "Time.h"
+
+static tmElements_t tm; // a cache of time elements
+static time_t cacheTime; // the time the cache was updated
+static time_t syncInterval = 300; // time sync will be attempted after this many seconds
+
+void refreshCache( time_t t){
+ if( t != cacheTime)
+ {
+ breakTime(t, tm);
+ cacheTime = t;
+ }
+}
+
+int hour() { // the hour now
+ return hour(now());
+}
+
+int hour(time_t t) { // the hour for the given time
+ refreshCache(t);
+ return tm.Hour;
+}
+
+int hourFormat12() { // the hour now in 12 hour format
+ return hourFormat12(now());
+}
+
+int hourFormat12(time_t t) { // the hour for the given time in 12 hour format
+ refreshCache(t);
+ if( tm.Hour == 0 )
+ return 12; // 12 midnight
+ else if( tm.Hour > 12)
+ return tm.Hour - 12 ;
+ else
+ return tm.Hour ;
+}
+
+uint8_t isAM() { // returns true if time now is AM
+ return !isPM(now());
+}
+
+uint8_t isAM(time_t t) { // returns true if given time is AM
+ return !isPM(t);
+}
+
+uint8_t isPM() { // returns true if PM
+ return isPM(now());
+}
+
+uint8_t isPM(time_t t) { // returns true if PM
+ return (hour(t) >= 12);
+}
+
+int minute() {
+ return minute(now());
+}
+
+int minute(time_t t) { // the minute for the given time
+ refreshCache(t);
+ return tm.Minute;
+}
+
+int second() {
+ return second(now());
+}
+
+int second(time_t t) { // the second for the given time
+ refreshCache(t);
+ return tm.Second;
+}
+
+int day(){
+ return(day(now()));
+}
+
+int day(time_t t) { // the day for the given time (0-6)
+ refreshCache(t);
+ return tm.Day;
+}
+
+int weekday() { // Sunday is day 1
+ return weekday(now());
+}
+
+int weekday(time_t t) {
+ refreshCache(t);
+ return tm.Wday;
+}
+
+int month(){
+ return month(now());
+}
+
+int month(time_t t) { // the month for the given time
+ refreshCache(t);
+ return tm.Month;
+}
+
+int year() { // as in Processing, the full four digit year: (2009, 2010 etc)
+ return year(now());
+}
+
+int year(time_t t) { // the year for the given time
+ refreshCache(t);
+ return tmYearToCalendar(tm.Year);
+}
+
+/*============================================================================*/
+/* functions to convert to and from system time */
+/* These are for interfacing with time serivces and are not normally needed in a sketch */
+
+// leap year calulator expects year argument as years offset from 1970
+#define LEAP_YEAR(Y) ( ((1970+Y)>0) && !((1970+Y)%4) && ( ((1970+Y)%100) || !((1970+Y)%400) ) )
+
+static const uint8_t monthDays[]={31,28,31,30,31,30,31,31,30,31,30,31}; // API starts months from 1, this array starts from 0
+
+void breakTime(time_t time, tmElements_t &tm){
+// break the given time_t into time components
+// this is a more compact version of the C library localtime function
+// note that year is offset from 1970 !!!
+
+ uint8_t year;
+ uint8_t month, monthLength;
+ unsigned long days;
+
+ tm.Second = time % 60;
+ time /= 60; // now it is minutes
+ tm.Minute = time % 60;
+ time /= 60; // now it is hours
+ tm.Hour = time % 24;
+ time /= 24; // now it is days
+ tm.Wday = ((time + 4) % 7) + 1; // Sunday is day 1
+
+ year = 0;
+ days = 0;
+ while((unsigned)(days += (LEAP_YEAR(year) ? 366 : 365)) <= time) {
+ year++;
+ }
+ tm.Year = year; // year is offset from 1970
+
+ days -= LEAP_YEAR(year) ? 366 : 365;
+ time -= days; // now it is days in this year, starting at 0
+
+ days=0;
+ month=0;
+ monthLength=0;
+ for (month=0; month<12; month++) {
+ if (month==1) { // february
+ if (LEAP_YEAR(year)) {
+ monthLength=29;
+ } else {
+ monthLength=28;
+ }
+ } else {
+ monthLength = monthDays[month];
+ }
+
+ if (time >= monthLength) {
+ time -= monthLength;
+ } else {
+ break;
+ }
+ }
+ tm.Month = month + 1; // jan is month 1
+ tm.Day = time + 1; // day of month
+}
+
+time_t makeTime(tmElements_t &tm){
+// assemble time elements into time_t
+// note year argument is offset from 1970 (see macros in time.h to convert to other formats)
+// previous version used full four digit year (or digits since 2000),i.e. 2009 was 2009 or 9
+
+ int i;
+ time_t seconds;
+
+ // seconds from 1970 till 1 jan 00:00:00 of the given year
+ seconds= tm.Year*(SECS_PER_DAY * 365);
+ for (i = 0; i < tm.Year; i++) {
+ if (LEAP_YEAR(i)) {
+ seconds += SECS_PER_DAY; // add extra days for leap years
+ }
+ }
+
+ // add days for this year, months start from 1
+ for (i = 1; i < tm.Month; i++) {
+ if ( (i == 2) && LEAP_YEAR(tm.Year)) {
+ seconds += SECS_PER_DAY * 29;
+ } else {
+ seconds += SECS_PER_DAY * monthDays[i-1]; //monthDay array starts from 0
+ }
+ }
+ seconds+= (tm.Day-1) * SECS_PER_DAY;
+ seconds+= tm.Hour * SECS_PER_HOUR;
+ seconds+= tm.Minute * SECS_PER_MIN;
+ seconds+= tm.Second;
+ return seconds;
+}
+/*=====================================================*/
+/* Low level system time functions */
+
+static time_t sysTime = 0;
+static time_t prevMillis = 0;
+static time_t nextSyncTime = 0;
+static timeStatus_t Status = timeNotSet;
+
+getExternalTime getTimePtr; // pointer to external sync function
+//setExternalTime setTimePtr; // not used in this version
+
+#ifdef TIME_DRIFT_INFO // define this to get drift data
+time_t sysUnsyncedTime = 0; // the time sysTime unadjusted by sync
+#endif
+
+
+time_t now(){
+ while( millis() - prevMillis >= 1000){
+ sysTime++;
+ prevMillis += 1000;
+#ifdef TIME_DRIFT_INFO
+ sysUnsyncedTime++; // this can be compared to the synced time to measure long term drift
+#endif
+ }
+ if(nextSyncTime <= sysTime){
+ if(getTimePtr != 0){
+ time_t t = getTimePtr();
+ if( t != 0)
+ setTime(t);
+ else
+ Status = (Status == timeNotSet) ? timeNotSet : timeNeedsSync;
+ }
+ }
+ return sysTime;
+}
+
+void setTime(time_t t){
+#ifdef TIME_DRIFT_INFO
+ if(sysUnsyncedTime == 0)
+ sysUnsyncedTime = t; // store the time of the first call to set a valid Time
+#endif
+
+ sysTime = t;
+ nextSyncTime = t + syncInterval;
+ Status = timeSet;
+ prevMillis = millis(); // restart counting from now (thanks to Korman for this fix)
+}
+
+void setTime(int hr,int min,int sec,int dy, int mnth, int yr){
+ // year can be given as full four digit year or two digts (2010 or 10 for 2010);
+ //it is converted to years since 1970
+ if( yr > 99)
+ yr = yr - 1970;
+ else
+ yr += 30;
+ tm.Year = yr;
+ tm.Month = mnth;
+ tm.Day = dy;
+ tm.Hour = hr;
+ tm.Minute = min;
+ tm.Second = sec;
+ setTime(makeTime(tm));
+}
+
+void adjustTime(long adjustment){
+ sysTime += adjustment;
+}
+
+timeStatus_t timeStatus(){ // indicates if time has been set and recently synchronized
+ return Status;
+}
+
+void setSyncProvider( getExternalTime getTimeFunction){
+ getTimePtr = getTimeFunction;
+ nextSyncTime = sysTime;
+ now(); // this will sync the clock
+}
+
+void setSyncInterval(time_t interval){ // set the number of seconds between re-sync
+ syncInterval = interval;
+} \ No newline at end of file