Introduced new TimeManager class with much better offline handling. Refactoring.

include/time_manager.h

@@ -0,0 +1,52 @@
+#ifndef TIME_MANAGER_H
+#define TIME_MANAGER_H
+
+#include <Arduino.h>
+#include <time.h>
+#include "udp_logger.h"
+
+#define NTP_MAX_UPDATE_TIME_US (500 * 1000) // 500ms max update time
+
+class TimeManager
+{
+public:
+    struct tm time_info(void);
+    bool ntp_sync_successful(void) const; // was there a NTP sync once?
+    bool ntp_time_update(bool init = false);
+    bool ntp_update_failed_prolonged(void) const; // indicates if maximum time since last NTP update was too long
+    void log_time(struct tm time_info) const;     // log local_time
+    void increment_time_now_local(void);
+
+    int tm_min(void);
+    int tm_hour(void);
+    int tm_year(void);
+    bool tm_isdst(void); // true if summertime
+
+    TimeManager(const char *tz,
+                const char *ntp_server,
+                uint32 ntp_update_period_s,
+                uint32 ntp_retry_delay_us,
+                uint32 ntp_max_offline_time_s,
+                UDPLogger *logger);
+
+private:
+    void set_up_ntp(void) const;       // set up NTP server
+    void set_up_timer_isr(void) const; // set up timer interrupt
+    const char *_tz;                   // timezone
+    const char *_ntp_server;           // used ntp server
+    UDPLogger *_logger;                // logger instance
+    struct tm _time_info;              // structure tm holds time information
+    time_t _time_now_local = 0;        // local timer value, updated by timer interrupt and synced by NTP when needed
+    time_t _time_now_ntp = 0;          // NTP timer value, seconds since Epoch (1970) - UTC, only synced by NTP request.
+    uint32 _ntp_max_offline_time_s;    // maximum time in seconds which is considered ok since last NTP update
+    uint32 _ntp_update_period_s;       // NTP request update period in seconds
+    uint32 _ntp_retry_delay_us;        // minimum retry delay in us between two NTP requests
+    uint32 _ntp_sync_timestamp_us = 0; // timestamp of last successful ntp update
+};
+
+inline void TimeManager::increment_time_now_local(void)
+{
+    _time_now_local++;
+}
+
+#endif /* TIME_MANAGER_H */

include/wordclock_constants.h

@@ -33,17 +33,18 @@
 #define NIGHTMODE_END_MIN (0)
 
 // Timings in us
-#define PERIOD_ANIMATION_US (200 * 1000)             // 200ms
-#define PERIOD_CLOCK_UPDATE_US (1 * 1000 * 1000)     // 1s
-#define PERIOD_HEARTBEAT_US (1 * 1000 * 1000)        // 1s
-#define PERIOD_MATRIX_UPDATE_US (100 * 1000)         // 100ms
-#define PERIOD_NIGHTMODE_CHECK_US (20 * 1000 * 1000) // 20s
-#define PERIOD_NTP_UPDATE_US (30 * 1000 * 1000)      // 30s
-#define PERIOD_PONG_US (10 * 1000)                   // 10ms
-#define PERIOD_SNAKE_US (50 * 1000)                  // 50ms
-#define PERIOD_STATE_CHANGE_US (10 * 1000 * 1000)    // 10s
-#define PERIOD_TETRIS_US (50 * 1000)                 // 50ms
-#define TIMEOUT_LEDDIRECT_US (5 * 1000 * 1000)       // 5s
+#define PERIOD_ANIMATION_US (200 * 1000)                   // 200ms
+#define PERIOD_CLOCK_UPDATE_US (1 * 1000 * 1000)           // 1s
+#define PERIOD_HEARTBEAT_US (1 * 1000 * 1000)              // 1s
+#define PERIOD_MATRIX_UPDATE_US (100 * 1000)               // 100ms
+#define PERIOD_NIGHTMODE_CHECK_US (20 * 1000 * 1000)       // 20s
+#define PERIOD_TIME_UPDATE_US (500 * 1000)                 // 500ms
+#define PERIOD_PONG_US (10 * 1000)                         // 10ms
+#define PERIOD_SNAKE_US (50 * 1000)                        // 50ms
+#define PERIOD_STATE_CHANGE_US (10 * 1000 * 1000)          // 10s
+#define PERIOD_TETRIS_US (50 * 1000)                       // 50ms
+#define TIMEOUT_LEDDIRECT_US (5 * 1000 * 1000)             // 5s
+#define PERIOD_BRIGHTNESS_UPDATE_US (5 * 60 * 1000 * 1000) // 300s
 
 #define SHORT_PRESS_US (100 * 1000)           // 100ms
 #define LONG_PRESS_US (2 * 1000 * 1000)       // 2s
@@ -68,11 +69,11 @@
 #define MATRIX_HEIGHT (11)
 
 // NTP macros
-#define BUILD_YEAR (__DATE__ + 7)                  /* Will expand to current year at compile time as string. */
-#define NTP_MININUM_RX_YEAR (atoi(BUILD_YEAR) - 1) /* Will expand to current year at compile time minus one. */
+#define BUILD_YEAR (__DATE__ + 7)                  // Will expand to current year at compile time as string.
+#define NTP_MININUM_RX_YEAR (atoi(BUILD_YEAR) - 1) // Will expand to current year minus one at compile time.
 #define NTP_MININUM_YEAR (1900)                    // NTP minimum year is 1900
-#define NTP_MAX_UPDATE_TIME_US (500000)    // 500ms max update time
-#define NTP_NEXT_UPDATE_DELAY_US (10000000)        // 10s delay time between updates
-#define NTP_WATCHDOG_COUNTER_INIT (30)             // Watchdog value, count of retries before restart
+#define NTP_UPDATE_PERIOD_S (12 * 3600)            // 12h period between updates
+#define NTP_RETRY_DELAY_US (10 * 1000 * 1000)      // 10s retry delay time between failed NTP requests
+#define NTP_MAX_OFFLINE_TIME_S (7 * 24 * 3600)     // Watchdog value, maxmimum offline time before a restart is triggered
 
 #endif /* WORDCLOCK_CONSTANTS_H */

include/wordclock_esp8266.h

@@ -61,12 +61,11 @@ typedef enum
 // ----------------------------------------------------------------------------------
 //                             FUNCTIONS DECLARATIONS
 // ----------------------------------------------------------------------------------
-bool get_ntp_time(uint32 timeout);
+bool check_wifi_status(void);
 String leading_zero2digit(int value);
 uint8_t calculate_dynamic_brightness(uint8_t min_brightness, uint8_t max_brightness, int hours, int minutes, bool summertime);
 uint8_t update_brightness(void);
 void check_night_mode(void);
-void check_wifi_status(void);
 void cold_start_setup(void);
 void draw_main_color(void);
 void handle_button(void);
@@ -76,8 +75,6 @@ void handle_data_request(void);
 void handle_led_direct(void);
 void limit_value_ranges(void);
 void log_data(void);
-void log_time(tm local_time);
-void ntp_time_update(uint32 max_update_time);
 void on_state_entry(uint8_t state);
 void read_settings_from_EEPROM(void);
 void reset_wifi_credentials(void);