Setup RTC if available and use it for time-keeping after an initial valid time has been retrieved from either the network or via NTP

Author: aentinger

src/ArduinoIoTCloudTCP.cpp

@@ -25,11 +25,6 @@
   #include <ArduinoECCX08.h>
 #endif
 
-#ifdef ARDUINO_ARCH_SAMD
-  #include <RTCZero.h>
-  RTCZero rtc;
-#endif
-
 TimeService time_service;
 
 #ifdef BOARD_HAS_ECCX08
@@ -44,11 +39,7 @@ const static int CONNECT_FAILURE							               = 0;
 const static int CONNECT_FAILURE_SUBSCRIBE					         = -1;
 
 static unsigned long getTime() {
-  unsigned long const time = time_service.getTime();
-  #ifdef ARDUINO_ARCH_SAMD
-  rtc.setEpoch(time);
-  #endif
-  return time;
+  return time_service.getTime();
 }
 
 ArduinoIoTCloudTCP::ArduinoIoTCloudTCP():
@@ -87,9 +78,6 @@ int ArduinoIoTCloudTCP::begin(TcpIpConnectionHandler & connection, String broker
   _brokerAddress = brokerAddress;
   _brokerPort = brokerPort;
   time_service.begin(&connection);
-  #ifdef ARDUINO_ARCH_SAMD
-  rtc.begin();
-  #endif
   return begin(_connection->getClient(), _brokerAddress, _brokerPort);
 }
 

src/utility/TimeService.cpp

@@ -28,6 +28,14 @@
 
 #include "NTPUtils.h"
 
+/**************************************************************************************
+ * GLOBAL VARIABLES
+ **************************************************************************************/
+
+#ifdef ARDUINO_ARCH_SAMD
+RTCZero rtc;
+#endif
+
 /**************************************************************************************
  * INTERNAL FUNCTION DECLARATION
  **************************************************************************************/
@@ -46,6 +54,9 @@ static time_t const EPOCH_AT_COMPILE_TIME = cvt_time(__DATE__);
 
 TimeService::TimeService()
 : _con_hdl(nullptr)
+#ifdef ARDUINO_ARCH_SAMD
+, _is_rtc_configured(false)
+#endif
 {
 
 }
@@ -57,9 +68,30 @@ TimeService::TimeService()
 void TimeService::begin(ConnectionHandler * con_hdl)
 {
   _con_hdl = con_hdl;
+#ifdef ARDUINO_ARCH_SAMD
+  rtc.begin();
+#endif
 }
 
 unsigned long TimeService::getTime()
+{
+#ifdef ARDUINO_ARCH_SAMD
+  if(!_is_rtc_configured)
+  {
+    rtc.setEpoch(getRemoteTime());
+    _is_rtc_configured = true;
+  }
+  return rtc.getEpoch();
+#else
+  return getRemoteTime();
+#endif
+}
+
+/**************************************************************************************
+ * PRIVATE MEMBER FUNCTIONS
+ **************************************************************************************/
+
+unsigned long TimeService::getRemoteTime()
 {
   if(_con_hdl == nullptr) return 0;
 
@@ -83,10 +115,6 @@ unsigned long TimeService::getTime()
   return 0;
 }
 
-/**************************************************************************************
- * PRIVATE MEMBER FUNCTIONS
- **************************************************************************************/
-
 bool TimeService::isTimeValid(unsigned long const time)
 {
   return (time >= EPOCH_AT_COMPILE_TIME);

src/utility/TimeService.h

@@ -27,6 +27,10 @@
 
 #include <Arduino_ConnectionHandler.h>
 
+#ifdef ARDUINO_ARCH_SAMD
+  #include <RTCZero.h>
+#endif
+
 /**************************************************************************************
  * CLASS DECLARATION
  **************************************************************************************/
@@ -45,7 +49,11 @@ class TimeService
 private:
 
   ConnectionHandler * _con_hdl;
+#ifdef ARDUINO_ARCH_SAMD
+  bool _is_rtc_configured;
+#endif
 
+  unsigned long getRemoteTime();
   static bool isTimeValid(unsigned long const time);
 
 };