Experimental timer-based RTC updates

src/WatchFace.cpp

@@ -92,7 +92,7 @@ void WatchFace::DrawWatchFace(bool partialRefresh)
   DrawBatteryIcon();
 
 	tmElements_t currentTime;
-	m_RTC.read(currentTime, m_tzOffset);
+	m_RTC.Get(currentTime, m_tzOffset);
 	SevenSegment sevenSegment(30, 60, 6, 5, 5);
 
   if (currentTime.Hour < 10) {

src/Watchy.cpp

@@ -17,9 +17,13 @@ void Watchy::Init()
   esp_sleep_wakeup_cause_t wakeup_reason;
   wakeup_reason = esp_sleep_get_wakeup_cause();
 
-  Wire.begin(SDA, SCL);
-  m_RTC.init();
+  if (wakeup_reason == ESP_SLEEP_WAKEUP_EXT0) {
+    if(!m_RTC.CheckWakeup()) {
+      DeepSleep();
+    }
+  }
 
+  Wire.begin(SDA, SCL);
   m_display.epd2.selectSPI(SPI, SPISettings(20000000, MSBFIRST, SPI_MODE0));
   m_display.init(0, g_displayFullInit, 10, true);
   SetBusyCallback();
@@ -63,6 +67,7 @@ void Watchy::Init()
     default:
     {
       BmaConfig();
+      m_RTC.Init();
       ConnectWiFi();
       SyncNTPTime();
       DisconnectWiFi();
@@ -83,7 +88,6 @@ void Watchy::DeepSleep()
   }
 
   g_displayFullInit = false; // Notify not to init it again
-  m_RTC.clearAlarm();        // resets the alarm flag in the RTC
 
   // Set GPIOs 0-39 to input to avoid power leaking out
   const uint64_t ignore = 0b11110001000000110000100111000010; // Ignore some GPIOs due to resets
@@ -97,6 +101,9 @@ void Watchy::DeepSleep()
   esp_sleep_enable_ext1_wakeup(
     BTN_PIN_MASK | ACC_INT_MASK,
     ESP_EXT1_WAKEUP_ANY_HIGH);
+
+  m_RTC.SetTimer();
+
   esp_deep_sleep_start();
 }
 
@@ -158,7 +165,7 @@ void Watchy::SyncNTPTime()
   if (success) {
     tmElements_t tm;
     breakTime((time_t)timeClient.getEpochTime(), tm);
-    m_RTC.set(tm);
+    m_RTC.Set(tm);
   } else {
     Serial.begin(9600);
     Serial.println("Failed to get NTP time");

src/WatchyRTC.cpp

@@ -1,58 +1,53 @@
 #include "WatchyRTC.h"
 
+#if (UPDATE_INTERVAL > 255)
+#error "UPDATE_INTERVAL must be either a multiple of 60, or less than 256 seconds"
+#endif
+
+RTC_DATA_ATTR bool WatchyRTC::m_timerSet = false;
+RTC_DATA_ATTR bool WatchyRTC::m_initialTimer = true;
+
 WatchyRTC::WatchyRTC()
 {
 }
 
-void WatchyRTC::init() {
-  byte error;
-  Wire.beginTransmission(RTC_PCF_ADDR);
-  error = Wire.endTransmission();
-}
-
-void WatchyRTC::config(String datetime) { // String datetime format is YYYY:MM:DD:HH:MM:SS
-  _PCFConfig(datetime);
-}
-
-void WatchyRTC::clearAlarm() {
-  int nextAlarmMinute = 0;
-  rtc_pcf.clearAlarm(); // resets the alarm flag in the RTC
-
-  int second = rtc_pcf.getSecond();
-  int minute = rtc_pcf.getMinute();
-  int hour = rtc_pcf.getHour();
-
-  minute += UPDATE_INTERVAL;
-
-  if (minute >= 60) {
-    hour += minute / 60;
-    minute = minute % 60;
-  }
-
-  rtc_pcf.setAlarm(minute, hour, 99, 99);
-}
-
-void WatchyRTC::read(tmElements_t & tm, int offsetInSeconds)
+void WatchyRTC::Init()
 {
-  rtc_pcf.getDate();
-  tm.Year  = y2kYearToTm(rtc_pcf.getYear());
+}
+
+void WatchyRTC::Get(tmElements_t & tm, int offsetInSeconds)
+{
+  rtc_pcf.getDateTime();
+  tm.Year = y2kYearToTm(rtc_pcf.getYear());
   tm.Month = rtc_pcf.getMonth();
-  tm.Day   = rtc_pcf.getDay();
-  tm.Wday = rtc_pcf.getWeekday() + 1; // TimeLib & DS3231 has Wday range of 1-7, but PCF8563 stores day of week in 0-6 range
-  tm.Hour   = rtc_pcf.getHour();
+  tm.Day = rtc_pcf.getDay();
+  tm.Wday = rtc_pcf.getWeekday() + 1; // TimeLib has Wday range of 1-7, but PCF8563 stores day of week in 0-6 range
+  tm.Hour = rtc_pcf.getHour();
   tm.Minute = rtc_pcf.getMinute();
   tm.Second = rtc_pcf.getSecond();
-
   OffsetTime(tm, offsetInSeconds);
 }
 
-void WatchyRTC::set(tmElements_t tm) {
+void WatchyRTC::Set(tmElements_t tm)
+{
   time_t t = makeTime(tm); // make and break to calculate tm.Wday
   breakTime(t, tm);
   // day, weekday, month, century(1=1900, 0=2000), year(0-99)
-  rtc_pcf.setDate(tm.Day, tm.Wday - 1, tm.Month, 0, tmYearToY2k(tm.Year));
-  rtc_pcf.setTime(tm.Hour, tm.Minute, tm.Second);
-  clearAlarm();
+  rtc_pcf.setDateTime(tm.Day, tm.Wday - 1, tm.Month, 0, tmYearToY2k(tm.Year), tm.Hour, tm.Minute, tm.Second);
+}
+
+void WatchyRTC::SetTimer()
+{
+  if (!m_timerSet) {
+    rtc_pcf.getDateTime();
+    // Sleep just long enough to get to a multiple of the update interval, makes updates happen on exact turn of the minute
+    int seconds = UPDATE_INTERVAL - (rtc_pcf.getSecond() % UPDATE_INTERVAL);
+
+    // Non repeating
+    rtc_pcf.setTimer(seconds, TMR_1Hz, false);
+    m_timerSet = true;
+    m_initialTimer = true;
+  }
 }
 
 void WatchyRTC::OffsetTime(tmElements_t & tm, int offsetInSeconds)
@@ -119,44 +114,25 @@ void WatchyRTC::OffsetTime(tmElements_t & tm, int offsetInSeconds)
   tm.Second = second;
 }
 
-void WatchyRTC::_PCFConfig(String datetime) { // String datetime is YYYY:MM:DD:HH:MM:SS
-  if (datetime != "") {
-    tmElements_t tm;
-    tm.Year = CalendarYrToTm(_getValue(datetime, ':', 0).toInt()); // YYYY -
-                                                                   // 1970
-    tm.Month  = _getValue(datetime, ':', 1).toInt();
-    tm.Day    = _getValue(datetime, ':', 2).toInt();
-    tm.Hour   = _getValue(datetime, ':', 3).toInt();
-    tm.Minute = _getValue(datetime, ':', 4).toInt();
-    tm.Second = _getValue(datetime, ':', 5).toInt();
-    time_t t  = makeTime(tm); // make and break to calculate tm.Wday
-    breakTime(t, tm);
-    // day, weekday, month, century(1=1900, 0=2000), year(0-99)
-    rtc_pcf.setDate(
-        tm.Day, tm.Wday - 1, tm.Month, 0,
-        tmYearToY2k(tm.Year)); // TimeLib & DS3231 has Wday range of 1-7, but
-                               // PCF8563 stores day of week in 0-6 range
-    // hr, min, sec
-    rtc_pcf.setTime(tm.Hour, tm.Minute, tm.Second);
-  }
+// TODO: implement more advanced wakeup logic, i.e. > 255 seconds that are not a multiple of 60
+bool WatchyRTC::CheckWakeup()
+{
+  if(m_initialTimer) {
+    m_initialTimer = false;
 
-  // on POR event, PCF8563 sets month to 0, which will give an error since
-  // months are 1-12
-  clearAlarm();
-}
-
-String WatchyRTC::_getValue(String data, char separator, int index) {
-  int found      = 0;
-  int strIndex[] = {0, -1};
-  int maxIndex   = data.length() - 1;
-
-  for (int i = 0; i <= maxIndex && found <= index; i++) {
-    if (data.charAt(i) == separator || i == maxIndex) {
-      found++;
-      strIndex[0] = strIndex[1] + 1;
-      strIndex[1] = (i == maxIndex) ? i + 1 : i;
+    byte frequency, interval;
+    if (UPDATE_INTERVAL % 60 == 0) {
+      frequency = TMR_1MIN; // 1 minute
+      interval = UPDATE_INTERVAL / 60;
+    } else {
+      frequency = TMR_1Hz; // 1 second
+      interval = UPDATE_INTERVAL;
     }
+
+    rtc_pcf.setTimer(interval, frequency, true);
+
+    return true;
   }
 
-  return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
-}
+  return true;
+}

src/WatchyRTC.h

@@ -15,17 +15,16 @@ public:
 
 public:
   WatchyRTC();
-  void init();
-  void config(String datetime); // String datetime format is YYYY:MM:DD:HH:MM:SS
-  void clearAlarm();
-  void read(tmElements_t & tm, int offsetInSeconds = 0);
-  void set(tmElements_t tm);
+  void Init();
+  void Get(tmElements_t & tm, int offsetInSeconds = 0);
+  void Set(tmElements_t tm);
+  void SetTimer();
+  bool CheckWakeup(); // Checks to really wake up or not, also resets the timer after the initial sleep
 
   static void OffsetTime(tmElements_t & tm, int offsetInSeconds);
 
 private:
-  void _PCFConfig(String datetime);
-  String _getValue(String data, char separator, int index);
+  static RTC_DATA_ATTR bool m_timerSet, m_initialTimer;
 };
 
 #endif

src/config.h

@@ -30,5 +30,5 @@
 
 #define NTP_SERVER "pool.ntp.org"
 
-#define UPDATE_INTERVAL 1
-#define WAKE_ON_ACCEL_EVENTS false
+#define UPDATE_INTERVAL 60 // seconds
+#define WAKE_ON_ACCEL_EVENTS false // useful if saving battery by not updating every minute