Use Singleton to have only one STM32RTC instance

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

Author: fpistm

README.md

@@ -6,6 +6,12 @@ A RTC library for STM32.
 This library is based on the Arduino RTCZero library.
 The library allows to take control of the internal RTC of the STM32 boards.
 
+Singleton design pattern is used to ensure that only one STM32RTC instance is instantiated:
+```
+/* Get the rtc object */
+STM32RTC& rtc = STM32RTC::getInstance();
+```
+
 The following functions are not supported:
 
 * **`void standbyMode()`**: use the STM32 Low Power library instead.

examples/Epoch/Epoch.ino

@@ -38,8 +38,8 @@
 
 #include <STM32RTC.h>
 
-/* Create a rtc object */
-STM32RTC rtc;
+/* Get the rtc object */
+STM32RTC& rtc = STM32RTC::getInstance();
 
 void setup() {
  Serial.begin(9600);

examples/RTCClockSelection/RTCClockSelection.ino

@@ -39,8 +39,8 @@
 
 #include <STM32RTC.h>
 
-/* Create a rtc object */
-STM32RTC rtc;
+/* Get the rtc object */
+STM32RTC& rtc = STM32RTC::getInstance();
 
 /* Change these values to set the current initial time */
 const byte seconds = 0;

examples/SimpleRTC/SimpleRTC.ino

@@ -38,8 +38,8 @@
 
 #include <STM32RTC.h>
 
-/* Create a rtc object */
-STM32RTC rtc;
+/* Get the rtc object */
+STM32RTC& rtc = STM32RTC::getInstance();
 
 /* Change these values to set the current initial time */
 const byte seconds = 0;

examples/simpleRTCAlarm/simpleRTCAlarm.ino

@@ -38,8 +38,8 @@
 
 #include <STM32RTC.h>
 
-/* Create a rtc object */
-STM32RTC rtc;
+/* Get the rtc object */
+STM32RTC& rtc = STM32RTC::getInstance();
 
 /* Change these values to set the current initial time */
 const byte seconds = 0;

keywords.txt

@@ -12,6 +12,8 @@ STM32RTC	KEYWORD1
 # Methods and Functions (KEYWORD2)
 #######################################
 
+getInstance	KEYWORD2
+
 getWeekDay	KEYWORD2
 getDay	KEYWORD2
 getMonth	KEYWORD2

src/STM32RTC.cpp

@@ -46,11 +46,6 @@
 // Initialize static variable
 bool STM32RTC::_configured = false;
 
-STM32RTC::STM32RTC(void): _clockSource(RTC_LSI_CLOCK)
-{
-
-}
-
 /**
  * @brief initializes the RTC
  * @param resetTime: if true reconfigures the RTC

src/STM32RTC.h

@@ -86,7 +86,14 @@ class STM32RTC {
  RTC_HSE_CLOCK = HSE_CLOCK
  };
 
- STM32RTC();
+ static STM32RTC& getInstance() {
+ static STM32RTC instance; // Guaranteed to be destroyed.
+ // Instantiated on first use.
+ return instance;
+ }
+
+ STM32RTC(STM32RTC const&) = delete;
+ void operator=(STM32RTC const&) = delete;
 
  void begin(bool resetTime, RTC_Hour_Format format = RTC_HOUR_24);
  void begin(RTC_Hour_Format format = RTC_HOUR_24);
@@ -177,6 +184,8 @@ class STM32RTC {
  }
 
 private:
+ STM32RTC(void): _clockSource(RTC_LSI_CLOCK) {}
+
  static bool _configured;
 
  RTC_AM_PM _hoursPeriod;
@@ -202,6 +211,7 @@ class STM32RTC {
  void syncTime(void);
  void syncDate(void);
  void syncAlarmTime(void);
+
 };
 
 #endif // __STM32_RTC_H