Added localtime support in addition to UTC

Enables schedules to be handled in local time or UTC as needed. System clock is always UTC but now the time offset enabes modules to know local time as well.

Author: fredilarsen

src/MI/ModuleInterface.h

@@ -68,8 +68,8 @@ static void dummy_notification_function(NotificationType /*notification_type*/,
 
 #define UTC_FIRST_ACCEPTED 1483228800ul
 
-  // The length of a status packet
-#define MI_STATUS_LEN 7 
+// The length of a status packet
+#define MI_STATUS_LEN 7
 
 /* Description of principle for bidirectional sync of settings:
 1. All modules get new settings from the master which retrieves them from a database regularly.
@@ -125,6 +125,7 @@ class ModuleInterface {
            time_utc_incremented_ms = 0,  // Last millis() when time_utc_s was incremented
            time_utc_received_s = 0,      // UTC time received last time, not incremented.
            time_utc_startup_s = 0;       // Startup time, for calculating uptime
+  int16_t  time_offset_m = 0;            // Current offset from GMT in minues, including DST
   #endif
   #endif
 
@@ -494,6 +495,8 @@ class ModuleInterface {
     update_time();
     return time_utc_received_s ? time_utc_s : 0;
   }
+  // Get offset in minutes from GMT, including DST and time zone
+  int16_t get_time_offset_m() { return time_offset_m; }
   #endif // !NO_TIME_SYNC
   #endif // !IS_MASTER
 
@@ -568,16 +571,19 @@ friend class ModuleInterfaceSet;
   // Receiving time sync from master
   void set_time(const uint8_t *message, const uint8_t length) {
     #ifndef NO_TIME_SYNC
-    if (length == 4) {
+    if (length >= 4) {
       uint32_t t;
+      int16_t offset = 0;
       memcpy(&t, message, sizeof t);
+      if (length >= 6) memcpy(&offset, &message[4], sizeof offset); // Take localtime offset if present (v5+)
       if (t > UTC_FIRST_ACCEPTED) {
         #ifdef DEBUG_PRINT
           uint32_t initial_time = get_time_utc_s();
         #endif
         time_utc_incremented_ms = millis(); // Remember when it was received so it can be auto-incremented
         time_utc_s = t;
         time_utc_received_s = time_utc_s; // Remember what time was received last
+        time_offset_m = offset;
         status_bits &= ~MISSING_TIME; // Clear the missing-time bit
         #ifdef DEBUG_PRINT
           dname(); DPRINT(F("Time adjusted by ")); DPRINT((uint32_t) (time_utc_s - initial_time));
@@ -593,7 +599,6 @@ friend class ModuleInterfaceSet;
   void set_status(const uint8_t *message, const uint8_t length) {
     if (length == 6) {
       last_alive = millis(); if (last_alive == 0) last_alive = 1;
-//      status_received_time = millis();
       comm_failures = 0;
       status_bits = message[0];
       out_of_memory = message[1];

src/MI_PJON/PJONModuleInterface.h

@@ -109,8 +109,8 @@ friend class PJONModuleInterfaceSet;
   }
 
   void update() {
-    // Listen for packets for 1ms
-    pjon->receive(1000);
+    // Listen for packets
+    pjon->receive();
 
     // Module-initiated event support
     send_output_events();

src/MI_PJON/PJONModuleInterfaceSet.h

@@ -258,8 +258,10 @@ class PJONModuleInterfaceSet : public ModuleInterfaceSet {
     char buf[5];
     buf[0] = (char) mcSetTime;
     uint32_t t = miTime::Get();
+    int16_t offset = miTime::GetTimeZoneOffsetMinutes();
     memcpy(&buf[1], &t, 4);
-    pjon->send_packet(id, bus_id, buf, 5, MI_REDUCED_SEND_TIMEOUT);
+    memcpy(&buf[5], &offset, 2);
+    pjon->send_packet(id, bus_id, buf, 7, MI_REDUCED_SEND_TIMEOUT);
     pjon->receive(); // Just called regularly to be responsive to events
   }
   #endif

src/utils/MITime.cpp

@@ -3,4 +3,4 @@
 uint32_t miTimeS = 0,                 // current time in UTC seconds, maintained by update()
          miLastUpdatedTimeMs = 0,     // system time in ms for last update()
          miLastSyncedMs = 0;          // system time in ms() for last setTime() call from external time source
- 
+int16_t  miTimeOffsetMinutes = 0;     // Time zone + DST current offset from UTC

src/utils/MITime.h

@@ -8,7 +8,7 @@
 extern uint32_t miTimeS,              // current time in UTC seconds, maintained by update()
                 miLastUpdatedTimeMs,  // system time in ms for last update()
                 miLastSyncedMs;       // system time in ms() for last setTime() call from external time source
- 
+ extern int16_t miTimeOffsetMinutes;  // Time zone + DST current offset from UTC
 
  struct miTime {
 
@@ -40,6 +40,23 @@ extern uint32_t miTimeS,              // current time in UTC seconds, maintained
   #endif
   }
 
+  // Return second count since 1970 local time
+  static uint32_t GetLocal() { return Get() + GetTimeZoneOffsetMinutes()*60L; }
+
+  static void SetTimeZoneOffsetMinutes(int16_t offset_minutes) { miTimeOffsetMinutes = offset_minutes; }
+
+  static int16_t GetTimeZoneOffsetMinutes() {
+  #ifdef MI_USE_SYSTEMTIME
+    // Do not keep track of time, just use the system time functions
+    time_t t = time(NULL);
+    struct tm lt;
+    localtime_r(&t, &lt);
+    return (int16_t) (lt.tm_gmtoff/60);
+  #else
+    return miTimeOffsetMinutes;
+  #endif
+  }
+
   static bool IsSynced() {
   #ifdef MI_USE_SYSTEMTIME
     return MI_SECONDS_YEAR_2017 < time(0);