stm32duino · fpistm · Jul 3, 2020 · Jun 2, 2020 · Jun 16, 2020 · Jun 26, 2020
diff --git a/README.md b/README.md
@@ -34,8 +34,8 @@ _RTC clock source_
 * **`void setClockSource(Source_Clock source)`** : this function must be called before `begin()`.
 
 _RTC Asynchronous and Synchronous prescaler_
-* **`void getPrediv(int8_t *predivA, int16_t *predivS)`** : get user (a)synchronous prescaler values if set else computed ones for the current clock source.
-* **`void setPrediv(int8_t predivA, int16_t predivS)`** : set user (a)synchronous prescaler values.  This function must be called before `begin()`. Use -1 to reset value and use computed ones.
+* **`void getPrediv(int8_t *predivA, int16_t *predivS)`** : get (a)synchronous prescaler values if set else computed ones for the current clock source.
+* **`void setPrediv(int8_t predivA, int16_t predivS)`** : set (a)synchronous prescaler values.  This function must be called before `begin()`. Use -1 to reset value and use computed ones. Those values have to match the following conditions: **_1Hz = RTC CLK source / ((predivA + 1) * (predivS + 1))_**
 
 _SubSeconds management_
 * **`uint32_t getSubSeconds(void)`**
@@ -62,6 +62,10 @@ _Time and date configuration (added for convenience)_
 
 _SubSeconds alarm management_
 
+  Important note:
+  - STM32F1 and STM32L1xx (Ultra Low Power Medium (ULPM) density) series do not support subsecond.
+  - Subsecond “resolution” depends on synchronous prescaler value. Bigger than this value is, better resolution will get for subsecond.
+
   * **`void setAlarmSubSeconds(uint32_t subSeconds)`**
 
   * **Updated API:**

diff --git a/examples/Epoch/Epoch.ino b/examples/Epoch/Epoch.ino
@@ -1,42 +1,20 @@
-/**
-  ******************************************************************************
-  * @file    Epoch.ino
-  * @author  WI6LABS
-  * @version V1.0.0
-  * @date    12-December-2017
-  * @brief   RTC epoch example
-  *
-  ******************************************************************************
-  * @attention
-  *
-  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
-  *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-  *
-  ******************************************************************************
-  */
+/*
+  Epoch
+
+  This sketch shows how to manage the RTC using Epoch time
+
+  Creation 12 Dec 2017
+  by Wi6Labs
+  Modified 03 Jul 2020
+  by Frederic Pillon for STMicroelectronics
+
+  This example code is in the public domain.
+
+  https://github.com/stm32duino/STM32RTC
+*/
 
 #include <STM32RTC.h>
+#include <time.h>
 
 /* Get the rtc object */
 STM32RTC& rtc = STM32RTC::getInstance();
@@ -54,35 +32,35 @@ void setup() {
 }
 
 void loop() {
+  uint32_t ss = rtc.getSubSeconds();
+  uint32_t epoch = rtc.getEpoch();
+  time_t rawtime = epoch;
+  struct tm ts;
+  char buf[80];
+
   Serial.print("Unix time = ");
-  Serial.println(rtc.getEpoch());
+  Serial.println(epoch);
 
   Serial.print("Seconds since Jan 1 2000 = ");
   Serial.println(rtc.getY2kEpoch());
 
-  // Print date...
-  Serial.print(rtc.getDay());
-  Serial.print("/");
-  Serial.print(rtc.getMonth());
-  Serial.print("/");
-  Serial.print(rtc.getYear());
-  Serial.print("\t");
-
-  // ...and time
-  print2digits(rtc.getHours());
-  Serial.print(":");
-  print2digits(rtc.getMinutes());
-  Serial.print(":");
-  print2digits(rtc.getSeconds());
-
+  // Format time, "ddd yyyy-mm-dd hh:mm:ss zzz"
+  ts = *localtime(&rawtime);
+  strftime(buf, sizeof(buf), "%a %Y-%m-%d %H:%M:%S", &ts);
+  Serial.print(buf);
+  Serial.print(".");
+  print2digits(ss);
   Serial.println();
 
-  delay(1000);
+  delay(678);
 }
 
-void print2digits(int number) {
+void print2digits(uint32_t number) {
+  if (number < 100) {
+    Serial.print("0");
+  }
   if (number < 10) {
     Serial.print("0");
   }
   Serial.print(number);
-}
+}
diff --git a/examples/RTCClockSelection/RTCClockSelection.ino b/examples/RTCClockSelection/RTCClockSelection.ino
@@ -1,41 +1,22 @@
-/**
-  ******************************************************************************
-  * @file    RTCClockSelection.ino
-  * @author  WI6LABS
-  * @version V1.0.0
-  * @date    15-March-2018
-  * @brief   RTC clock selection: LSI, LSE or HSE. Refer to board datasheet to
-  *          know available clock.
-  *
-  ******************************************************************************
-  * @attention
-  *
-  * <h2><center>&copy; COPYRIGHT(c) 2018 STMicroelectronics</center></h2>
-  *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-  *
-  ******************************************************************************
-  */
+/*
+  RTCClockSelection
+
+  This sketch shows how to select one of the RTC clock:
+   - LSI (default)
+   - LSE
+   - HSE
+
+  Refer to board datasheet to know available clock
+
+  Creation 15 March 2018
+  by Wi6Labs
+  Modified 03 Jul 2020
+  by Frederic Pillon for STMicroelectronics
+
+  This example code is in the public domain.
+
+  https://github.com/stm32duino/STM32RTC
+*/
 
 #include <STM32RTC.h>
 
@@ -96,17 +77,19 @@ void loop()
   print2digits(rtc.getMinutes());
   Serial.print(":");
   print2digits(rtc.getSeconds());
-
+  Serial.print(".");
+  print2digits(rtc.getSubSeconds());
   Serial.println();
 
   delay(1000);
 }
 
-
-
 void print2digits(int number) {
+  if (number < 100) {
+    Serial.print("0");
+  }
   if (number < 10) {
-    Serial.print("0"); // print a 0 before if the number is < than 10
+    Serial.print("0");
   }
   Serial.print(number);
-}
+}
diff --git a/examples/SimpleRTC/SimpleRTC.ino b/examples/SimpleRTC/SimpleRTC.ino
@@ -1,40 +1,18 @@
-/**
-  ******************************************************************************
-  * @file    SimpleRTC.ino
-  * @author  WI6LABS
-  * @version V1.0.0
-  * @date    12-December-2017
-  * @brief   Simple RTC example.
-  *
-  ******************************************************************************
-  * @attention
-  *
-  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
-  *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-  *
-  ******************************************************************************
-  */
+/*
+  SimpleRTC
+
+  This sketch shows how to configure the RTC and to display
+  the date and time periodically
+
+  Creation 12 Dec 2017
+  by Wi6Labs
+  Modified 03 Jul 2020
+  by Frederic Pillon for STMicroelectronics
+
+  This example code is in the public domain.
+
+  https://github.com/stm32duino/STM32RTC
+*/
 
 #include <STM32RTC.h>
 
@@ -95,17 +73,19 @@ void loop()
   print2digits(rtc.getMinutes());
   Serial.print(":");
   print2digits(rtc.getSeconds());
-
+  Serial.print(".");
+  print2digits(rtc.getSubSeconds());
   Serial.println();
 
   delay(1000);
 }
 
-
-
 void print2digits(int number) {
+  if (number < 100) {
+    Serial.print("0");
+  }
   if (number < 10) {
-    Serial.print("0"); // print a 0 before if the number is < than 10
+    Serial.print("0");
   }
   Serial.print(number);
-}
+}
diff --git a/examples/advancedRTCAlarm/advancedRTCAlarm.ino b/examples/advancedRTCAlarm/advancedRTCAlarm.ino
@@ -5,14 +5,14 @@
   It uses the optional 'data' alarm callback parameters to
   reload alarm with 'atime' offset indefinitely.
 
-
   Creation 25 May 2018
   by Frederic Pillon for STMicroelectronics
+  Modified 03 Jul 2020
+  by Frederic Pillon for STMicroelectronics
 
   This example code is in the public domain.
 
   https://github.com/stm32duino/STM32RTC
-
 */
 
 #include <STM32RTC.h>
@@ -23,8 +23,9 @@ STM32RTC& rtc = STM32RTC::getInstance();
 /* Declare it volatile since it's incremented inside an interrupt */
 volatile int alarmMatch_counter = 0;
 
-/* Change this value to set alarm match offset */
-static uint32_t atime = 5;
+/* Change this value to set alarm match offset in millisecond */
+/* Note that STM32F1xx does not manage subsecond only second */
+static uint32_t atime = 678;
 
 /* Change these values to set the current initial time */
 const byte seconds = 0;
@@ -51,7 +52,7 @@ void setup()
 
   rtc.attachInterrupt(alarmMatch, &atime);
   rtc.setAlarmDay(day);
-  rtc.setAlarmTime(16, 0, 10);
+  rtc.setAlarmTime(16, 0, 10, 567);
   rtc.enableAlarm(rtc.MATCH_DHHMMSS);
 }
 
@@ -62,16 +63,37 @@ void loop()
 
 void alarmMatch(void *data)
 {
-  uint32_t sec = 1;
-  if(data != NULL) {
-    sec = *(uint32_t*)data;
+  uint32_t epoc;
+  uint32_t epoc_ms;
+  uint32_t sec = 0;
+  uint32_t _millis = 1000;
+
+  if (data != NULL) {
+    _millis = *(uint32_t*)data;
     // Minimum is 1 second
-    if (sec == 0){
+    if (sec == 0) {
       sec = 1;
     }
   }
-  alarmMatch_counter++;
-  Serial.print("Alarm Match ");
-  Serial.println(alarmMatch_counter);
-  rtc.setAlarmEpoch( rtc.getEpoch() + sec);
+
+  sec = _millis / 1000;
+#ifdef STM32F1xx
+  // Minimum is 1 second
+  if (sec == 0) {
+    sec = 1;
+  }
+  epoc = rtc.getEpoch(&epoc_ms);
+#else
+  _millis = _millis % 1000;
+  epoc = rtc.getEpoch(&epoc_ms);
+
+  //Update epoch_ms - might need to add a second to epoch
+  epoc_ms += _millis;
+  if (epoc_ms >= 1000) {
+    sec ++;
+    epoc_ms -= 1000;
+  }
+#endif
+  Serial.printf("Alarm Match %i\n", ++alarmMatch_counter);
+  rtc.setAlarmEpoch(epoc + sec, STM32RTC::MATCH_SS, epoc_ms);
 }