ESP TimeService: remove delays introduced by NTP requests

README.md

@@ -88,6 +88,5 @@ OTA is supported by the following boards:
 Support for ESP boards is obtained through a third-party core with some differences and limitations compared to Arduino boards.
 
 - **Authentication scheme**: Board authentication is done through `DEVICE_LOGIN_NAME` and `DEVICE_KEY`, both values are included in the `thingProperties.h` file.
-- **RTC**: RTC support is not included thus each `ArduinoCould.update()` call will lead to an NTP request introducing delay in your `loop()` function. The scheduler widget will not work correctly if connection is lost after configuration.
 - **Watchdog**: Watchdog support is not included.
 - **OTA**: OTA support is not included

src/property/Property.cpp

@@ -21,10 +21,6 @@
 #undef min
 #include <algorithm>
 
-#if !defined ARDUINO_ARCH_SAMD && !defined ARDUINO_ARCH_MBED
-  #pragma message "No RTC available on this architecture - ArduinoIoTCloud will not keep track of local change timestamps ."
-#endif
-
 /******************************************************************************
    CTOR/DTOR
  ******************************************************************************/

src/utility/time/TimeService.cpp

@@ -43,6 +43,9 @@ time_t cvt_time(char const * time);
  * CONSTANTS
  **************************************************************************************/
 
+#ifdef ARDUINO_ARCH_ESP8266
+static unsigned long const AIOT_TIMESERVICE_ESP8266_NTP_SYNC_TIMEOUT_ms = 86400000;
+#endif
 static time_t const EPOCH_AT_COMPILE_TIME = cvt_time(__DATE__);
 static time_t const EPOCH = 0;
 
@@ -52,12 +55,15 @@ static time_t const EPOCH = 0;
 
 TimeService::TimeService()
 : _con_hdl(nullptr)
-#if defined (ARDUINO_ARCH_SAMD) || defined (ARDUINO_ARCH_MBED)
 , _is_rtc_configured(false)
-#endif
 , _is_tz_configured(false)
 , _timezone_offset(0)
 , _timezone_dst_until(0)
+#ifdef ARDUINO_ARCH_ESP8266
+, _last_ntp_sync_tick(0)
+, _last_rtc_update_tick(0)
+, _rtc(0)
+#endif
 {
 
 }
@@ -100,6 +106,35 @@ unsigned long TimeService::getTime()
     return utc;
   }
   return time(NULL);
+#elif ARDUINO_ARCH_ESP32
+  if(!_is_rtc_configured)
+  {
+    configTime(0, 0, "time.arduino.cc", "pool.ntp.org", "time.nist.gov");
+    _is_rtc_configured = true;
+  }
+  return time(NULL);
+#elif ARDUINO_ARCH_ESP8266
+  unsigned long const now = millis();
+  bool const is_ntp_sync_timeout = (now - _last_ntp_sync_tick) > AIOT_TIMESERVICE_ESP8266_NTP_SYNC_TIMEOUT_ms;
+  if(!_is_rtc_configured || is_ntp_sync_timeout)
+  {
+    _is_rtc_configured = false;
+    unsigned long utc = getRemoteTime();
+    if(EPOCH_AT_COMPILE_TIME != utc)
+    {
+      _rtc = utc;
+      _last_ntp_sync_tick = now;
+      _last_rtc_update_tick = now;
+      _is_rtc_configured = true;
+    }
+    return utc;
+  }
+  unsigned long const elapsed_s = (now - _last_rtc_update_tick) / 1000;
+  if(elapsed_s) {
+    _rtc += elapsed_s;
+    _last_rtc_update_tick = now;
+  }
+  return _rtc;
 #else
   return getRemoteTime();
 #endif

src/utility/time/TimeService.h

@@ -56,12 +56,15 @@ class TimeService
 private:
 
   ConnectionHandler * _con_hdl;
-#if defined (ARDUINO_ARCH_SAMD) || defined (ARDUINO_ARCH_MBED)
   bool _is_rtc_configured;
-#endif
   bool _is_tz_configured;
   long _timezone_offset;
   unsigned long _timezone_dst_until;
+#ifdef ARDUINO_ARCH_ESP8266
+  unsigned long _last_ntp_sync_tick;
+  unsigned long _last_rtc_update_tick;
+  unsigned long _rtc;
+#endif
 
   unsigned long getRemoteTime();
   bool connected();