timekeeper once again reworked and shortened

include/globals.h

@@ -41,9 +41,9 @@
 #define SCREEN_MODE (0x80)
 
 // I2C bus access control
-#define I2C_MUTEX_LOCK()                                                       \
+#define I2C_MUTEX_LOCK()
-  xSemaphoreTake(I2Caccess, (3 * DISPLAYREFRESH_MS / portTICK_PERIOD_MS)) ==   \
+xSemaphoreTake(I2Caccess,
-      pdTRUE
+               (3 * DISPLAYREFRESH_MS / portTICK_PERIOD_MS)) == pdTRUE
 #define I2C_MUTEX_UNLOCK() xSemaphoreGive(I2Caccess)
 
     // Struct holding devices's runtime configuration
@@ -108,7 +108,8 @@ extern char display_line6[], display_line7[]; // screen buffers
 extern uint8_t volatile channel;              // wifi channel rotation counter
 extern uint16_t volatile macs_total, macs_wifi, macs_ble,
     batt_voltage;                   // display values
-extern bool volatile TimePulseTick; // one-pulse-per-second flags set by GPS or RTC
+extern bool volatile TimePulseTick; // one-pulse-per-second flags set by GPS or
+                                    // RTC
 extern hw_timer_t *sendCycle, *displaytimer, *clockCycle;
 extern SemaphoreHandle_t I2Caccess, TimePulse;
 extern TaskHandle_t irqHandlerTask, ClockTask;

include/gpsread.h

@@ -3,6 +3,7 @@
 
 #include <TinyGPS++.h> // library for parsing NMEA data
 #include <RtcDateTime.h>
+#include "timekeeper.h"
 
 #ifdef GPS_I2C // Needed for reading from I2C Bus
 #include <Wire.h>

include/if482.h

@@ -2,6 +2,7 @@
 #define _IF482_H
 
 #include "globals.h"
+#include "timekeeper.h"
 
 #define IF482_FRAME_SIZE (17)
 #define IF482_PULSE_LENGTH (1000)
@@ -10,7 +11,5 @@ extern HardwareSerial IF482;
 
 void IF482_Pulse(time_t t);
 String IRAM_ATTR IF482_Frame(time_t tt);
-TickType_t tx_Ticks(unsigned long baud, uint32_t config, int8_t rxPin,
-                   int8_t txPins);
 
 #endif

include/timekeeper.h

@@ -20,12 +20,13 @@ void clock_init(void);
 void clock_loop(void *pvParameters);
 time_t time_sync(void);
 void timepulse_start(void);
-time_t syncTime(getExternalTime getTimeFunction, timesource_t const caller);
 uint8_t timepulse_init(void);
-uint8_t TimeIsValid(time_t const t);
+time_t TimeIsValid(time_t const t);
 time_t syncProvider_CB(void);
 time_t compiledUTC(void);
 time_t tmConvert(uint16_t YYYY, uint8_t MM, uint8_t DD, uint8_t hh, uint8_t mm,
                  uint8_t ss);
+TickType_t tx_Ticks(uint32_t framesize, unsigned long baud, uint32_t config,
+                    int8_t rxPin, int8_t txPins);
 
 #endif // _timekeeper_H

src/gpsread.cpp

@@ -75,22 +75,29 @@ void gps_read() {
 
 // function to fetch current time from gps
 time_t get_gpstime(void) {
+
+#define NMEA_FRAME_SIZE 80 // NEMA has a maxium of 80 bytes per record
+#define NMEA_BUFFER 50     // 50ms safety time regardless
+
   time_t t = 0;
 
-  if ((gps.time.age() < 950) && (gps.time.isValid())) {
+// set timeout for reading recent time from GPS
+#ifdef GPS_SERIAL // serial GPS
+  static const TickType_t txDelay =
+      pdMS_TO_TICKS(1000 - NMEA_BUFFER - tx_Ticks(NMEA_FRAME_SIZE, GPS_SERIAL));
+#else // I2C GPS
+  static const TickType_t txDelay = 1000 - NMEA_BUFFER;
+#endif
+
+  if ((gps.time.age() < txDelay) && (gps.time.isValid())) {
 
     ESP_LOGD(TAG, "GPS time age: %dms, is valid: %s", gps.time.age(),
              gps.time.isValid() ? "yes" : "no");
 
-    // use recent gps time
     t = tmConvert(gps.date.year(), gps.date.month(), gps.date.day(),
                   gps.time.hour(), gps.time.minute(), gps.time.second());
-
-    // ESP_LOGD(TAG, "GPS time: %02d.%02d.%04d %02d:%02d:%02d", gps.date.day(),
-    //         gps.date.month(), gps.date.year(), gps.time.hour(),
-    //         gps.time.minute(), gps.time.second());
   }
-  return t;
+  return TimeIsValid(t);
 } // get_gpstime()
 
 // GPS serial feed FreeRTos Task

src/if482.cpp

@@ -90,7 +90,7 @@ HardwareSerial IF482(2); // use UART #2 (note: #1 may be in use for serial GPS)
 void IF482_Pulse(time_t t) {
 
   static const TickType_t txDelay =
-      pdMS_TO_TICKS(IF482_PULSE_LENGTH) - tx_Ticks(HAS_IF482);
+      pdMS_TO_TICKS(IF482_PULSE_LENGTH - tx_Ticks(IF482_FRAME_SIZE, HAS_IF482));
 
   TickType_t startTime = xTaskGetTickCount();
 
@@ -124,17 +124,4 @@ String IRAM_ATTR IF482_Frame(time_t startTime) {
   return out;
 }
 
-// calculate serial tx time from IF482 serial settings
-TickType_t tx_Ticks(unsigned long baud, uint32_t config, int8_t rxPin,
-                    int8_t txPins) {
-
-  uint32_t databits = ((config & 0x0c) >> 2) + 5;
-  uint32_t stopbits = ((config & 0x20) >> 5) + 1;
-  uint32_t txTime =
-      (databits + stopbits + 2) * IF482_FRAME_SIZE * 1000.0 / baud;
-  // +2 ms margin for the startbit and the clock's processing time
-
-  return pdMS_TO_TICKS(round(txTime));
-}
-
 #endif // HAS_IF482

src/lorawan.cpp

@@ -474,6 +474,7 @@ void user_request_network_time_callback(void *pVoidUserUTCTime,
   // Update system time with time read from the network
   if (TimeIsValid(*pUserUTCTime)) {
     setTime(*pUserUTCTime);
+    timeSource = _lora;
     ESP_LOGI(TAG, "Received recent time from LoRa");
     }
   else

src/rtctime.cpp

@@ -67,7 +67,7 @@ time_t get_rtctime(void) {
     }
     I2C_MUTEX_UNLOCK();
   }
-  return t;
+  return TimeIsValid(t);
 } // get_rtctime()
 
 float get_rtctemp(void) {

src/timekeeper.cpp

@@ -13,18 +13,26 @@ time_t time_sync() {
 
   time_t t = 0;
 
-#ifdef TIME_SYNC_INTERVAL
-
 #ifdef HAS_GPS
-  t = syncTime(get_gpstime, _gps);
+  xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
-  if (t)
+  ESP_LOGD(TAG, "micros = %d", micros());
-    return t; // attempt sync with GPS time
+  t = get_gpstime();
+  if (t) {
+    t++; // gps time concerns past second, so we add one second
+#ifdef HAS_RTC
+    set_rtctime(t); // calibrate RTC
+#endif
+    timeSource = _gps;
+    goto exit;
+  }
 #endif
 
 // no GPS -> fallback to RTC time while trying lora sync
 #ifdef HAS_RTC
-  t = syncTime(get_rtctime, _rtc); // sync with RTC time
+  t = get_rtctime();
-  if (!t)
+  if (t)
+    timeSource = _rtc;
+  else
     ESP_LOGW(TAG, "no confident RTC time");
 #endif
 
@@ -33,45 +41,18 @@ time_t time_sync() {
   LMIC_requestNetworkTime(user_request_network_time_callback, &userUTCTime);
 #endif
 
-#endif // TIME_SYNC_INTERVAL
+exit:
+  ESP_LOGD(TAG, "micros = %d", micros());
+  if (t)
+    ESP_LOGD(TAG, "Time was set by %c to %02d:%02d:%02d",
+             timeSetSymbols[timeSource], hour(t), minute(t), second(t));
+  else
+    timeSource = _unsynced;
 
   return t;
+
 } // time_sync()
 
-// sync time on start of next second from GPS or RTC
-time_t syncTime(getExternalTime getTimeFunction, timesource_t const caller) {
-
-  time_t t;
-  TimeSourcePtr = getTimeFunction;
-  if (!TimeSourcePtr)
-    goto error;
-
-  xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
-
-  t = TimeSourcePtr(); // get time from given timesource
-
-  if (TimeIsValid(t)) {
-    if (caller == _gps) // gps time concerns past second
-      t++;
-    timeSource = caller;
-    ESP_LOGD(TAG, "Time source %c set time to %02d:%02d:%02d",
-             timeSetSymbols[timeSource], hour(t), minute(t), second(t));
-
-#ifdef HAS_RTC
-    if (caller != _rtc)
-      set_rtctime(t);
-#endif
-
-    return t; // success
-  }
-
-error:
-  ESP_LOGD(TAG, "Time source %c sync attempt failed", timeSetSymbols[caller]);
-  timeSource = _unsynced;
-  return 0; // failure
-
-} // syncTime()
-
 // helper function to setup a pulse per second for time synchronisation
 uint8_t timepulse_init() {
 
@@ -136,11 +117,11 @@ void IRAM_ATTR CLOCKIRQ(void) {
 }
 
 // helper function to check plausibility of a time
-uint8_t TimeIsValid(time_t const t) {
+time_t TimeIsValid(time_t const t) {
   // is it a time in the past? we use compile date to guess
   ESP_LOGD(TAG, "t=%d, tt=%d, valid: %s", t, compiledUTC(),
            (t >= compiledUTC()) ? "yes" : "no");
-  return (t >= compiledUTC());
+  return (t >= compiledUTC() ? t : 0);
 }
 
 // helper function to convert compile time to UTC time
@@ -162,6 +143,18 @@ time_t tmConvert(uint16_t YYYY, uint8_t MM, uint8_t DD, uint8_t hh, uint8_t mm,
   return makeTime(tm);
 }
 
+// helper function to calculate serial transmit time
+TickType_t tx_Ticks(uint32_t framesize, unsigned long baud, uint32_t config,
+                    int8_t rxPin, int8_t txPins) {
+
+  uint32_t databits = ((config & 0x0c) >> 2) + 5;
+  uint32_t stopbits = ((config & 0x20) >> 5) + 1;
+  uint32_t txTime = (databits + stopbits + 2) * framesize * 1000.0 / baud;
+  // +1 ms margin for the startbit +1 ms for pending processing time
+
+  return round(txTime);
+}
+
 #if defined HAS_IF482 || defined HAS_DCF77
 
 #if defined HAS_DCF77 && defined HAS_IF482