Revert "Removed code using <time.h> non-core library (ie. Epoch stuff)"

This reverts commit ece522d.

Author: stephenf7072

libraries/RTC/examples/Example4_Set_Epoch/Example4_Set_Epoch.ino

@@ -0,0 +1,41 @@
+/* 
+  Author: Adam Garbo and Nathan Seidle
+  Created: June 3rd, 2020
+  License: MIT. See SparkFun Arduino Apollo3 Project for more information
+
+  This example demonstrates how to set the RTC using UNIX Epoch time.
+*/
+
+#include "RTC.h" // Include RTC library included with the Aruino_Apollo3 core
+APM3_RTC myRTC; // Create instance of RTC class
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println("SparkFun RTC Set UNIX Epoch Time Example");
+
+  // Set the RTC time using UNIX Epoch time
+  myRTC.setEpoch(1591185600); // E.g. 12:00:00, June 3rd, 2020 
+}
+
+void loop()
+{
+  // Print UNIX Epoch timestamp
+  Serial.print("Epoch time: "); Serial.println(myRTC.getEpoch());
+  
+  // Print RTC's date and time
+  Serial.print("Timestamp: "); printDateTime();
+
+  delay(1000);
+}
+
+// Print the RTC's current date and time
+void printDateTime()
+{
+  myRTC.getTime();
+  char dateTime[20];
+  sprintf(dateTime, "20%02d-%02d-%02d %02d:%02d:%02d",
+          myRTC.year, myRTC.month, myRTC.dayOfMonth,
+          myRTC.hour, myRTC.minute, myRTC.seconds);
+  Serial.println(dateTime);
+}

libraries/RTC/keywords.txt

@@ -13,9 +13,11 @@ RTC	KEYWORD1
 #######################################
 
 getTime	KEYWORD2
+getEpoch	KEYWORD2
 
 setTime	KEYWORD2
 setTimeToCompiler	KEYWORD2
+setEpoch	KEYWORD2
 
 getAlarm	KEYWORD2
 setAlarm	KEYWORD2

libraries/RTC/src/RTC.cpp

@@ -3,6 +3,7 @@
 */
 
 #include "RTC.h"
+#include <time.h>
 
 am_hal_rtc_time_t hal_time;
 am_hal_rtc_time_t alm_time;
@@ -88,6 +89,28 @@ void APM3_RTC::setToCompilerTime()
   getTime();
 }
 
+void APM3_RTC::setEpoch(uint32_t ts)
+{
+  if (ts < EPOCH_TIME) {
+    ts = EPOCH_TIME;
+  }
+
+  struct tm tm;
+
+  time_t t = ts;
+  struct tm* tmp = gmtime(&t);
+  hal_time.ui32Weekday = 0;
+  hal_time.ui32Century = 0;
+  hal_time.ui32Year = tmp->tm_year - 100;
+  hal_time.ui32Month = tmp->tm_mon + 1;
+  hal_time.ui32DayOfMonth = tmp->tm_mday;
+  hal_time.ui32Hour = tmp->tm_hour;
+  hal_time.ui32Minute = tmp->tm_min;
+  hal_time.ui32Second = tmp->tm_sec;
+  hal_time.ui32Hundredths = 0;
+
+  am_hal_rtc_time_set(&hal_time); //Initialize the RTC with this date/time
+}
 
 void APM3_RTC::getTime()
 {
@@ -104,6 +127,24 @@ void APM3_RTC::getTime()
   hundredths = hal_time.ui32Hundredths;
 }
 
+uint32_t APM3_RTC::getEpoch()
+{
+  am_hal_rtc_time_get(&hal_time);
+
+  struct tm tm;
+
+  tm.tm_isdst = -1;
+  tm.tm_yday = 0;
+  tm.tm_wday = 0;
+  tm.tm_year = hal_time.ui32Year + 100; //Number of years since 1900.
+  tm.tm_mon = hal_time.ui32Month - 1; //mktime is expecting 0 to 11 months
+  tm.tm_mday = hal_time.ui32DayOfMonth;
+  tm.tm_hour = hal_time.ui32Hour;
+  tm.tm_min = hal_time.ui32Minute;
+  tm.tm_sec = hal_time.ui32Second;
+
+  return mktime(&tm);
+}
 
 void APM3_RTC::getAlarm()
 {

libraries/RTC/src/RTC.h

@@ -9,10 +9,12 @@ class APM3_RTC
   APM3_RTC();
 
   void getTime(); //Query the RTC for the current time/date
+  uint32_t getEpoch(); //Return the current RTC time/date as UNIX Epoch time 
 
   void setTime(uint8_t hour, uint8_t min, uint8_t sec, uint8_t hund,
                uint8_t dayOfMonth, uint8_t month, uint16_t year); //Set current time to provided hundredths/seconds/etc
   void setToCompilerTime(); //Set to time when sketch was compiled
+  void setEpoch(uint32_t ts); //Set current time to provided UNIX Epoch time
 
   void getAlarm(); //Query the RTC for the current alarm time/date
   void setAlarm(uint8_t hour, uint8_t min, uint8_t sec, uint8_t hund, uint8_t dayOfMonth, uint8_t month); //Set alarm time to provided hundredths/seconds/etc