v1.7.31 (clockcontroller deeply reworked)

include/clockcontroller.h

@@ -11,5 +11,6 @@
 
 void clock_init(void);
 void clock_loop(void *pvParameters);
+time_t telegram_time(void);
 
 #endif // _CLOCKCONTROLLER_H

include/cyclic.h

@@ -5,15 +5,14 @@
 #include "senddata.h"
 #include "rcommand.h"
 #include "spislave.h"
+#include "rtctime.h"
 #include <lmic.h>
 
 #ifdef HAS_BME
 #include "bme680mems.h"
 #endif
 
-#ifdef HAS_RTC
+
-#include "rtctime.h"
-#endif
 
 void doHousekeeping(void);
 uint64_t uptime(void);

include/dcf77.h

@@ -3,11 +3,16 @@
 
 #include "globals.h"
 
+#define DCF77_FRAME_SIZE (60)
+#define DCF77_PULSE_LENGTH (100)
+
+extern uint8_t DCFpulse[];
+
 enum dcf_pulses { dcf_off, dcf_zero, dcf_one };
 enum dcf_pinstate { dcf_low, dcf_high };
 
-void DCF_Pulse(time_t startTime);
+void DCF_Pulse(time_t t);
-void DCF77_Frame(time_t t);
+void IRAM_ATTR DCF77_Frame(time_t t);
 void set_DCF77_pin(dcf_pinstate state);
 uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos, uint8_t pArray[]);
 

include/globals.h

@@ -45,13 +45,6 @@
       pdTRUE
 #define I2C_MUTEX_UNLOCK() xSemaphoreGive(I2Caccess)
 
-// Clock controller settings
-#define PPS (1000) // on board time pulse frequency in ms
-#define IF482_FRAME_SIZE (17)
-#define IF482_PULSE_LENGTH (1000)
-#define DCF77_FRAME_SIZE (60)
-#define DCF77_PULSE_LENGTH (100)
-
 // Struct holding devices's runtime configuration
 typedef struct {
   uint8_t lorasf;      // 7-12, lora spreadfactor
@@ -104,20 +97,19 @@ typedef struct {
 
 enum sendprio_t { prio_low, prio_normal, prio_high };
 
-// global variables
+extern std::set<uint16_t, std::less<uint16_t>, Mallocator<uint16_t>> macs;
+extern std::array<uint64_t, 0xff>::iterator it;
+extern std::array<uint64_t, 0xff> beacons;
+
 extern configData_t cfg;                      // current device configuration
 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;
 extern hw_timer_t *sendCycle, *displaytimer;
 extern SemaphoreHandle_t I2Caccess, TimePulse;
-
+extern TaskHandle_t irqHandlerTask, ClockTask;
-extern std::set<uint16_t, std::less<uint16_t>, Mallocator<uint16_t>> macs;
-extern std::array<uint64_t, 0xff>::iterator it;
-extern std::array<uint64_t, 0xff> beacons;
-
-extern TaskHandle_t irqHandlerTask;
 extern TimerHandle_t WifiChanTimer;
 extern Timezone myTZ;
 

include/if482.h

@@ -3,10 +3,13 @@
 
 #include "globals.h"
 
+#define IF482_FRAME_SIZE (17)
+#define IF482_PULSE_LENGTH (1000)
+
 extern HardwareSerial IF482; 
 
 void IF482_Pulse(time_t t);
-String IF482_Frame(time_t tt);
+String IRAM_ATTR IF482_Frame(time_t tt);
 TickType_t tx_Ticks(unsigned long baud, uint32_t config, int8_t rxPin,
                    int8_t txPins);
 

include/lorawan.h

@@ -10,16 +10,14 @@
 #include <SPI.h>
 #include <arduino_lmic_hal_boards.h>
 #include "loraconf.h"
+#include "rtctime.h"
 
 // Needed for 24AA02E64, does not hurt anything if included and not used
 #ifdef MCP_24AA02E64_I2C_ADDRESS
 #include <Wire.h>
 #endif
 
-// Needed for RTC time sync if RTC present on board
+
-#ifdef HAS_RTC
-#include "rtctime.h"
-#endif
 
 extern QueueHandle_t LoraSendQueue;
 

include/main.h

@@ -17,5 +17,6 @@
 #include "led.h"
 #include "spislave.h"
 #include "lorawan.h"
+#include "rtctime.h"
 #include "clockcontroller.h"
 #endif

include/rtctime.h

@@ -11,20 +11,17 @@
 
 extern RtcDS3231<TwoWire> Rtc; // make RTC instance globally available
 
-extern TaskHandle_t ClockTask;
-extern hw_timer_t *clockCycle;
-extern bool volatile TimePulseTick;
-
 int rtc_init(void);
 int set_rtctime(uint32_t t);
 int set_rtctime(time_t t);
 void sync_rtctime(void);
 time_t get_rtctime(void);
 float get_rtctemp(void);
-void IRAM_ATTR CLOCKIRQ();
+void IRAM_ATTR CLOCKIRQ(void);
 int timepulse_init(void);
-void timepulse_start();
+void timepulse_start(void);
 int sync_TimePulse(void);
 int sync_SysTime(time_t);
+int sync_SysTime(uint32_t t);
 
 #endif // _RTCTIME_H

platformio.ini

@@ -30,7 +30,7 @@ description = Paxcounter is a proof-of-concept ESP32 device for metering passeng
 
 [common]
 ; for release_version use max. 10 chars total, use any decimal format like "a.b.c"
-release_version = 1.7.24
+release_version = 1.7.31
 ; DEBUG LEVEL: For production run set to 0, otherwise device will leak RAM while running!
 ; 0=None, 1=Error, 2=Warn, 3=Info, 4=Debug, 5=Verbose
 debug_level = 0
@@ -67,7 +67,7 @@ lib_deps_all =
 build_flags_basic =
     -include "src/hal/${PIOENV}.h"
     -include "src/paxcounter.conf"
-    -w
+ ;   -w
     '-DARDUINO_LMIC_PROJECT_CONFIG_H=../../../src/lmic_config.h'
     '-DCORE_DEBUG_LEVEL=${common.debug_level}'
     '-DLOG_LOCAL_LEVEL=${common.debug_level}'

src/clockcontroller.cpp

@@ -6,25 +6,16 @@
 #error You must define at most one of IF482 or DCF77!
 #endif
 
-#if (PPS < IF482_PULSE_LENGTH) || (PPS < DCF77_PULSE_LENGTH)
-#error On board timepulse too fast for clockcontroller
-#endif
-
 // Local logging tag
 static const char TAG[] = "main";
 
-void clock_init(void) { // ClockTask
+void clock_init(void) {
 
-  timepulse_init(); // setup timepulse
+// setup clock output interface
-
-// setup output interface
 #ifdef HAS_IF482
-  // initialize and configure IF482 Generator
   IF482.begin(HAS_IF482);
 #elif defined HAS_DCF77
-  // initialize and configure DCF77 output
   pinMode(HAS_DCF77, OUTPUT);
-  set_DCF77_pin(dcf_low);
 #endif
 
   xTaskCreatePinnedToCore(clock_loop,  // task function
@@ -36,37 +27,68 @@ void clock_init(void) { // ClockTask
                           0);          // CPU core
 
   assert(ClockTask); // has clock task started?
-  timepulse_start(); // start pulse
 } // clock_init
 
 void clock_loop(void *pvParameters) { // ClockTask
 
   configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check
 
-  TickType_t wakeTime, txDelay;
+  TickType_t wakeTime;
-  uint32_t pulseCycle;
+  time_t t;
-  void (*pTimeTx)(time_t); // pointer to time telegram output function
 
-#ifdef HAS_IF482
+#define t1(t) (t + DCF77_FRAME_SIZE + 1) // future time for next frame
-  txDelay = pdMS_TO_TICKS(1000) - tx_Ticks(HAS_IF482);
+
-  pulseCycle = PPS / IF482_PULSE_LENGTH;
+// preload first DCF frame before start
-  pTimeTx = IF482_Pulse;
+#ifdef HAS_DCF77
-#elif defined HAS_DCF77
+  DCF77_Frame(t1(telegram_time()));
-  txDelay = pdMS_TO_TICKS(DCF77_PULSE_LENGTH);
-  pulseCycle = PPS / DCF77_PULSE_LENGTH;
-  pTimeTx = DCF_Pulse;
 #endif
 
-  // output time telegram triggered by timepulse
+  // output time telegram for second following sec beginning with timepulse
   for (;;) {
-    if (timeStatus() == timeSet) // do we have valid time?
+    xTaskNotifyWait(0x00, ULONG_MAX, &wakeTime,
-      xTaskNotifyWait(0x00, ULONG_MAX, &wakeTime,
+                    portMAX_DELAY); // wait for timepulse
-                      portMAX_DELAY); // wait for timepulse
+
-    for (uint8_t i = 1; i <= pulseCycle; i++) {
+    if (timeStatus() == timeNotSet) // do we have valid time?
-      pTimeTx(now());
+      continue;
-      vTaskDelayUntil(&wakeTime, txDelay);
+
-    }
+    t = telegram_time(); // time to send to clock
+
+#if defined HAS_IF482
+
+    IF482_Pulse(t + 1); // next second
+
+#elif defined HAS_DCF77
+
+    if (ts == DCF77_FRAME_SIZE - 1) // moment to reload frame?
+      DCF77_Frame(t1(t));           // generate next frame
+
+    if (DCFpulse[DCF77_FRAME_SIZE] ==
+        minute(t1(t)))  // do he have a recent frame?
+      DCF_Pulse(t + 1); // then output next second of current frame
+
+#endif
+
   } // for
 } // clock_loop()
 
-#endif // HAS_DCF77 || HAS_IF482
+// helper function to fetch current second from most precise time source
+time_t telegram_time(void) {
+  time_t t;
+
+#ifdef HAS_GPS // gps is our primary time source if present
+  t = get_gpstime();
+  if (t) // did we get a valid time?
+    return t;
+#endif
+
+#ifdef HAS_RTC // rtc is our secondary time source if present
+  t = get_rtctime();
+  if (t)
+    return t;
+#endif
+
+  // else we use systime as fallback source
+  return now();
+}
+
+#endif // HAS_IF482 || defined HAS_DCF77

src/cyclic.cpp

@@ -9,7 +9,7 @@ static const char TAG[] = "main";
 
 time_t userUTCTime; // Seconds since the UTC epoch
 unsigned long nextLoraTimeSync = millis();
-unsigned long nextRTCTimeSync = millis() + TIME_WRITE_INTERVAL_RTC * 60000;
+unsigned long nextGPSTimeSync = millis();
 
 // do all housekeeping
 void doHousekeeping() {
@@ -24,8 +24,26 @@ void doHousekeeping() {
   spi_housekeeping();
   lora_housekeeping();
 
-// do cyclic time sync with LORA network
+// do cyclic sync of systime with GPS timepulse, if present
-#ifdef TIME_SYNC_INTERVAL_LORA
+#if defined HAS_GPS && defined TIME_SYNC_INTERVAL_GPS
+  if (millis() >= nextGPSTimeSync) {
+    nextGPSTimeSync = millis() + TIME_SYNC_INTERVAL_GPS *
+                                     60000; // set up next time sync period
+
+    // sync systime on next timepulse
+    if (sync_SysTime(get_gpstime())) {
+      //setSyncProvider(get_gpstime);
+#ifdef HAS_RTC
+      set_rtctime(now()); // epoch time
+#endif
+      ESP_LOGI(TAG, "GPS has set the system time");
+    } else
+      ESP_LOGI(TAG, "Unable to sync system time with GPS");
+  } // if
+#endif
+
+// do cyclic time sync with LORA network, if present
+#if defined HAS_LORA && defined TIME_SYNC_INTERVAL_LORA
   if (millis() >= nextLoraTimeSync) {
     nextLoraTimeSync = millis() + TIME_SYNC_INTERVAL_LORA *
                                       60000; // set up next time sync period
@@ -35,20 +53,6 @@ void doHousekeeping() {
   }
 #endif
 
-// do cyclic write back system time to RTC if we have an external time source
-#if (defined TIME_SYNC_INTERVAL_LORA || defined TIME_SYNC_INTERVAL_GPS) &&     \
-    defined HAS_RTC
-  if ((millis() >= nextRTCTimeSync) && (timeStatus() == timeSet)) {
-    nextRTCTimeSync = millis() + TIME_WRITE_INTERVAL_RTC *
-                                     60000; // set up next time sync period
-    sync_TimePulse();                       // wait for next start of second
-    if (!set_rtctime(now()))                // epoch time
-      ESP_LOGE(TAG, "RTC set time failure");
-    else
-      ESP_LOGI(TAG, "RTC time updated");
-  }
-#endif
-
   // task storage debugging //
   ESP_LOGD(TAG, "IRQhandler %d bytes left | Taskstate = %d",
            uxTaskGetStackHighWaterMark(irqHandlerTask),

src/dcf77.cpp

@@ -1,5 +1,5 @@
 /*
-// Emulate a DCF77 radio receiver
+// Emulate a DCF77 radio receiver to control an external clock
 //
 // a nice & free logic test program for DCF77 can be found here:
 https://www-user.tu-chemnitz.de/~heha/viewzip.cgi/hs/Funkuhr.zip/
@@ -13,36 +13,32 @@ https://www-user.tu-chemnitz.de/~heha/viewzip.cgi/hs/Funkuhr.zip/
 // Local logging tag
 static const char TAG[] = "main";
 
-// array of dcf pulses for three minutes
+// array of dcf pulses for one minute
-uint8_t DCFpulse[DCF77_FRAME_SIZE];
+uint8_t DCFpulse[DCF77_FRAME_SIZE + 1];
 
-// called by timepulse interrupt to ticker out DCF signal
+// triggered by 1 second timepulse to ticker out DCF signal
-void DCF_Pulse(time_t startTime) {
+void DCF_Pulse(time_t t) {
 
-  static uint8_t current_second = second(startTime);
+  uint8_t sec = second(t);
-  static uint8_t pulse = 0;
-  static bool SecondsPending = false;
 
-  if (!SecondsPending) {
+  TickType_t startTime = xTaskGetTickCount();
-    // prepare dcf timeframe to send for next minute
-    DCF77_Frame(now() + DCF77_FRAME_SIZE + 1);
-    ESP_LOGD(TAG, "DCF77 minute %d", minute(now() + DCF77_FRAME_SIZE + 1));
-    // begin output of dcf timeframe
-    SecondsPending = true;
-  }
 
-  // ticker out current DCF frame
+  ESP_LOGD(TAG, "DCF77 sec %d", sec);
-  if (SecondsPending) {
+
-    switch (pulse++) {
+  // induce 10 pulses
+  for (uint8_t pulse = 0; pulse <= 9; pulse++) {
+
+    switch (pulse) {
 
     case 0: // start of second -> start of timeframe for logic signal
-      if (DCFpulse[current_second] != dcf_off)
+      if (DCFpulse[sec] != dcf_off)
         set_DCF77_pin(dcf_low);
-      ESP_LOGD(TAG, "DCF77 bit %d", current_second);
+      else // 59th second reached, nothing more to do
+        return;
       break;
 
     case 1: // 100ms after start of second -> end of timeframe for logic 0
-      if (DCFpulse[current_second] == dcf_zero)
+      if (DCFpulse[sec] == dcf_zero)
         set_DCF77_pin(dcf_high);
       break;
 
@@ -50,22 +46,69 @@ void DCF_Pulse(time_t startTime) {
       set_DCF77_pin(dcf_high);
       break;
 
-    case 9: // 900ms after start -> last pulse before next second starts
+    case 9: // 900ms after start -> last pulse
-      pulse = 0;
+      return;
-      if (current_second++ >=
-          (DCF77_FRAME_SIZE - 1)) // end of DCF77 frame (59th second)
-      {
-        current_second = 0;
-        SecondsPending = false;
-      };
-      break;
 
-    }; // switch
+    } // switch
-  };   // if
+
+    vTaskDelayUntil(&startTime, pdMS_TO_TICKS(DCF77_PULSE_LENGTH));
+
+  } // for
 } // DCF_Pulse()
 
+void IRAM_ATTR DCF77_Frame(time_t tt) {
+
+  uint8_t Parity;
+  time_t t = myTZ.toLocal(tt); // convert to local time
+
+  ESP_LOGD(TAG, "DCF77 minute %d", minute(t));
+
+  // ENCODE HEAD
+  // secs 0..19 initialized with zeros
+  for (int n = 0; n <= 19; n++)
+    DCFpulse[n] = dcf_zero;
+  // secs 17..18: adjust for DayLightSaving
+  DCFpulse[18 - (myTZ.locIsDST(t) ? 1 : 0)] = dcf_one;
+  // sec 20: must be 1 to indicate time active
+  DCFpulse[20] = dcf_one;
+
+  // ENCODE MINUTE (secs 21..28)
+  Parity = dec2bcd(minute(t), 21, 27, DCFpulse);
+  DCFpulse[28] = (Parity & 1) ? dcf_one : dcf_zero;
+
+  // ENCODE HOUR (secs 29..35)
+  Parity = dec2bcd(hour(t), 29, 34, DCFpulse);
+  DCFpulse[35] = (Parity & 1) ? dcf_one : dcf_zero;
+
+  // ENCODE DATE (secs 36..58)
+  Parity = dec2bcd(day(t), 36, 41, DCFpulse);
+  Parity += dec2bcd((weekday(t) - 1) ? (weekday(t) - 1) : 7, 42, 44, DCFpulse);
+  Parity += dec2bcd(month(t), 45, 49, DCFpulse);
+  Parity += dec2bcd(year(t) - 2000, 50, 57,
+                    DCFpulse); // yes, we have a millenium 3000 bug here ;-)
+  DCFpulse[58] = (Parity & 1) ? dcf_one : dcf_zero;
+
+  // ENCODE TAIL (sec 59)
+  DCFpulse[59] = dcf_off;
+  // !! missing code here for leap second !!
+
+  // timestamp the frame with minute pointer
+  DCFpulse[60] = minute(t);
+
+  /*
+    // for debug: print the DCF77 frame buffer
+    char out[DCF77_FRAME_SIZE + 1];
+    uint8_t i;
+    for (i = 0; i < DCF77_FRAME_SIZE; i++) {
+      out[i] = DCFpulse[i] + '0'; // convert int digit to printable ascii
+    }
+    out[DCF77_FRAME_SIZE] = '\0'; // string termination char
+    ESP_LOGD(TAG, "DCF minute %d = %s", DCFpulse[DCF77_FRAME_SIZE], out);
+  */
+}
+
 // helper function to convert decimal to bcd digit
-uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos,
+uint8_t IRAM_ATTR dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos,
                 uint8_t pArray[]) {
 
   uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
@@ -80,52 +123,6 @@ uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos,
   return parity;
 }
 
-void DCF77_Frame(time_t tt) {
-
-  uint8_t Parity;
-  time_t t = myTZ.toLocal(tt); // convert to local time
-
-  // ENCODE HEAD
-  // bits 0..19 initialized with zeros
-  for (int n = 0; n <= 19; n++)
-    DCFpulse[n] = dcf_zero;
-  // bits 17..18: adjust for DayLightSaving
-  DCFpulse[18 - (myTZ.locIsDST(t) ? 1 : 0)] = dcf_one;
-  // bit 20: must be 1 to indicate time active
-  DCFpulse[20] = dcf_one;
-
-  // ENCODE MINUTE (bits 21..28)
-  Parity = dec2bcd(minute(t), 21, 27, DCFpulse);
-  DCFpulse[28] = (Parity & 1) ? dcf_one : dcf_zero;
-
-  // ENCODE HOUR (bits 29..35)
-  Parity = dec2bcd(hour(t), 29, 34, DCFpulse);
-  DCFpulse[35] = (Parity & 1) ? dcf_one : dcf_zero;
-
-  // ENCODE DATE (bits 36..58)
-  Parity = dec2bcd(day(t), 36, 41, DCFpulse);
-  Parity += dec2bcd((weekday(t) - 1) ? (weekday(t) - 1) : 7, 42, 44, DCFpulse);
-  Parity += dec2bcd(month(t), 45, 49, DCFpulse);
-  Parity += dec2bcd(year(t) - 2000, 50, 57,
-                    DCFpulse); // yes, we have a millenium 3000 bug here ;-)
-  DCFpulse[58] = (Parity & 1) ? dcf_one : dcf_zero;
-
-  // ENCODE TAIL (bit 59)
-  DCFpulse[59] = dcf_off;
-  // !! missing code here for leap second !!
-
-  /*
-    // for debug: print the DCF77 frame buffer
-    char out[DCF77_FRAME_SIZE + 1];
-    uint8_t i;
-    for (i = 0; i < DCF77_FRAME_SIZE; i++) {
-      out[i] = DCFpulse[i] + '0'; // convert int digit to printable ascii
-    }
-    out[DCF77_FRAME_SIZE] = '\0'; // string termination char
-    ESP_LOGD(TAG, "DCF Timeframe = %s", out);
-  */
-}
-
 // helper function to switch GPIO line with DCF77 signal
 void set_DCF77_pin(dcf_pinstate state) {
   switch (state) {
@@ -146,6 +143,4 @@ void set_DCF77_pin(dcf_pinstate state) {
   } // switch
 } // DCF77_pulse
 
-// helper function calculates next minute
-
 #endif // HAS_DCF77

src/gpsread.cpp

@@ -96,8 +96,6 @@ time_t get_gpstime(void) {
     time_t t =
         tmConvert_t(gps.date.year(), gps.date.month(), gps.date.day(),
                     gps.time.hour(), gps.time.minute(), gps.time.second());
-    ESP_LOGD(TAG, "GPS time: %4d/%02d/%02d %02d:%02d:%02d", year(t), month(t),
-             day(t), hour(t), minute(t), second(t));
     return t;
   } else {
     ESP_LOGW(TAG, "GPS has no confident time");

src/if482.cpp

@@ -86,12 +86,16 @@ static const char TAG[] = "main";
 
 HardwareSerial IF482(2); // use UART #2 (note: #1 may be in use for serial GPS)
 
-// called by timepulse interrupt to ticker out DCF signal
+// triggered by timepulse to ticker out DCF signal
-void IF482_Pulse(time_t startTime) {
+void IF482_Pulse(time_t t) {
-  IF482.print(IF482_Frame(startTime + 1)); // if482 telegram for next second
+
+  TickType_t startTime = xTaskGetTickCount();
+  static const TickType_t txDelay = pdMS_TO_TICKS(IF482_PULSE_LENGTH) - tx_Ticks(HAS_IF482);
+  vTaskDelayUntil(&startTime, txDelay);
+  IF482.print(IF482_Frame(t+1)); // note: if482 telegram for *next* second
 }
 
-String IF482_Frame(time_t startTime) {
+String IRAM_ATTR IF482_Frame(time_t startTime) {
 
   time_t t = myTZ.toLocal(startTime);
   char mon, buf[14], out[IF482_FRAME_SIZE];
@@ -103,19 +107,14 @@ String IF482_Frame(time_t startTime) {
   case timeNeedsSync: // time had been set but sync attempt did not succeed
     mon = 'M';
     break;
-  default: // time not set, no valid time
+  default: // unknown time status (should never be reached)
     mon = '?';
     break;
   } // switch
 
-  // do we have confident time/date?
+  // generate IF482 telegram
-  if (timeStatus() == timeSet)
+  snprintf(buf, sizeof(buf), "%02u%02u%02u%1u%02u%02u%02u", year(t) - 2000,
-    snprintf(buf, sizeof(buf), "%02u%02u%02u%1u%02u%02u%02u", year(t) - 2000,
+           month(t), day(t), weekday(t), hour(t), minute(t), second(t));
-             month(t), day(t), weekday(t), hour(t), minute(t), second(t));
-  else
-    snprintf(buf, sizeof(buf), "000000F000000"); // no confident time/date
-
-  // output IF482 telegram
   snprintf(out, sizeof(out), "O%cL%s\r", mon, buf);
   ESP_LOGD(TAG, "IF482 = %s", out);
   return out;
@@ -127,8 +126,11 @@ TickType_t tx_Ticks(unsigned long baud, uint32_t config, int8_t rxPin,
 
   uint32_t datenbits = ((config & 0x0c) >> 2) + 5;
   uint32_t stopbits = ((config & 0x20) >> 5) + 1;
-  return pdMS_TO_TICKS(
+  uint32_t tx_delay =
-      round(((1 + datenbits + stopbits) * IF482_FRAME_SIZE * 1000.0 / baud)));
+      (2 + datenbits + stopbits) * IF482_FRAME_SIZE * 1000.0 / baud;
+  // +2 ms margin for the startbit and the clock's processing time
+
+  return pdMS_TO_TICKS(round(tx_delay));
 }
 
 #endif // HAS_IF482

src/lorawan.cpp

@@ -399,7 +399,7 @@ esp_err_t lora_stack_init() {
   }
 
   return ESP_OK; // continue main program
-#endif
+#endif // HAS_LORA
 }
 
 void lora_enqueuedata(MessageBuffer_t *message, sendprio_t prio) {
@@ -439,6 +439,7 @@ void lora_housekeeping(void) {
 
 void user_request_network_time_callback(void *pVoidUserUTCTime,
                                         int flagSuccess) {
+#ifdef HAS_LORA
   // Explicit conversion from void* to uint32_t* to avoid compiler errors
   uint32_t *pUserUTCTime = (uint32_t *)pVoidUserUTCTime;
   lmic_time_reference_t lmicTimeReference;
@@ -468,11 +469,14 @@ void user_request_network_time_callback(void *pVoidUserUTCTime,
   *pUserUTCTime += requestDelaySec;
 
   // Update system time with time read from the network
-  setTime(*pUserUTCTime);
+  if (sync_TimePulse()) {              // wait for start of next second
-  ESP_LOGI(TAG, "LoRaWAN network has set the system time");
+    if (sync_SysTime(*pUserUTCTime)) { // do we have a valid time?
 #ifdef HAS_RTC
-  sync_TimePulse();                // wait for next start of second
+      set_rtctime(now()); // epoch time
-  if (!set_rtctime(*pUserUTCTime+1)) // epoch time
-    ESP_LOGE(TAG, "RTC set time failure");
 #endif
-}
+      ESP_LOGI(TAG, "LORA has set the system time");
+    }
+  } else
+    ESP_LOGI(TAG, "Unable to sync system time with LORA");
+#endif // HAS_LORA
+} // user_request_network_time_callback

src/main.cpp

@@ -27,9 +27,8 @@ Uused tasks and timers:
 
 Task          Core  Prio  Purpose
 ====================================================================================
+clockloop     0     4     generates realtime telegrams for external clock
 ledloop       0     3     blinks LEDs
-if482loop     0     3     generates serial feed of IF482 time telegrams
-dcf77loop     0     3     generates DCF77 timeframe pulses
 spiloop       0     2     reads/writes data on spi interface
 IDLE          0     0     ESP32 arduino scheduler -> runs wifi sniffer
 
@@ -71,8 +70,9 @@ hw_timer_t *sendCycle = NULL, *homeCycle = NULL;
 hw_timer_t *displaytimer = NULL;
 #endif
 
-TaskHandle_t irqHandlerTask;
+TaskHandle_t irqHandlerTask, ClockTask;
 SemaphoreHandle_t I2Caccess, TimePulse;
+bool volatile TimePulseTick = false;
 
 // container holding unique MAC address hashes with Memory Alloctor using PSRAM,
 // if present
@@ -334,24 +334,17 @@ void setup() {
   strcat_P(features, " LPPPKD");
 #endif
 
-// initialize RTC
+  // initialize RTC
 #ifdef HAS_RTC
   strcat_P(features, " RTC");
   assert(rtc_init());
-  sync_TimePulse();             // wait for next start of second
+#endif
-  setSyncProvider(get_rtctime); // sync time now and then
-  if (timeStatus() != timeSet)
-    ESP_LOGI(TAG, "Unable to sync system time with RTC");
-  else
-    ESP_LOGI(TAG, "RTC has set the system time");
-  setSyncInterval(TIME_SYNC_INTERVAL_RTC * 60);
-#endif // HAS_RTC
 
 #if defined HAS_DCF77
   strcat_P(features, " DCF77");
 #endif
 
-#if defined HAS_IF482 && defined RTC_INT
+#if defined HAS_IF482
   strcat_P(features, " IF482");
 #endif
 
@@ -365,6 +358,13 @@ void setup() {
 #endif
 #endif
 
+  // start pps timepulse
+  ESP_LOGI(TAG, "Starting timepulse...");
+  if (timepulse_init()) // setup timepulse
+    timepulse_start();  // start pulse
+  else
+    ESP_LOGE(TAG, "No timepulse, systime will not be synced!");
+
   // start wifi in monitor mode and start channel rotation timer
   ESP_LOGI(TAG, "Starting Wifi...");
   wifi_sniffer_init();
@@ -417,19 +417,29 @@ void setup() {
 #endif // HAS_BUTTON
 
 #ifdef HAS_GPS
-  sync_TimePulse();             // wait for next start of second
+  // sync systime on next timepulse
-  setSyncProvider(get_gpstime); // sync time now and then
+  ESP_LOGI(TAG, "GPS is setting system time");
-  if (timeStatus() != timeSet)
+  if (sync_SysTime(get_gpstime())) {
-    ESP_LOGI(TAG, "Unable to sync system time with GPS");
+    //setSyncProvider(get_gpstime); // reset sync cycle on top of second
-  else {
+    //setSyncInterval(TIME_SYNC_INTERVAL_GPS * 60);
-    ESP_LOGI(TAG, "GPS has set the system time");
+    // calibrate RTC
 #ifdef HAS_RTC
-    if (!set_rtctime(now())) // epoch time
+    set_rtctime(now()); // epoch time
-      ESP_LOGE(TAG, "RTC set time failure");
-#endif
-  }
-  setSyncInterval(TIME_SYNC_INTERVAL_GPS * 60);
 #endif
+  } else
+    ESP_LOGI(TAG, "Unable to sync system time with GPS");
+#endif // HAS_GPS
+
+    // initialize systime from timesource
+#ifdef HAS_RTC
+  // sync systime on next timepulse
+  ESP_LOGI(TAG, "RTC is setting system time");
+  if (sync_SysTime(get_rtctime())) {
+    //setSyncProvider(get_rtctime); // reset sync cycle on top of second
+    //setSyncInterval(TIME_SYNC_INTERVAL_RTC * 60);
+  } else
+    ESP_LOGI(TAG, "Unable to sync system time with RTC");
+#endif // HAS_RTC
 
 #if defined HAS_IF482 || defined HAS_DCF77
   ESP_LOGI(TAG, "Starting Clock Controller...");
@@ -439,7 +449,6 @@ void setup() {
 } // setup()
 
 void loop() {
-
   while (1) {
 #ifdef HAS_LORA
     os_runloop_once(); // execute lmic scheduled jobs and events

src/paxcounter.conf

@@ -84,7 +84,6 @@
 // settings for syncing time of node and external time sources
 #define TIME_SYNC_INTERVAL_GPS          5       // sync time each .. minutes from GPS [default = 5], comment out means off          
 #define TIME_SYNC_INTERVAL_RTC          60      // sync time each .. minutes from RTC [default = 60], comment out means off          
-#define TIME_WRITE_INTERVAL_RTC         60      // write time each .. minutes from GPS/LORA to RTC [default = 60], comment out means off          
 //#define TIME_SYNC_INTERVAL_LORA       60      // sync time each .. minutes from LORA network [default = 60], comment out means off
 
 // time zone, see https://github.com/JChristensen/Timezone/blob/master/examples/WorldClock/WorldClock.ino

src/rtctime.cpp

@@ -3,9 +3,7 @@
 // Local logging tag
 static const char TAG[] = "main";
 
-TaskHandle_t ClockTask;
 hw_timer_t *clockCycle = NULL;
-bool volatile TimePulseTick = false;
 
 // helper function to setup a pulse per second for time synchronisation
 int timepulse_init() {
@@ -41,7 +39,6 @@ int timepulse_init() {
 #else
   // use ESP32 hardware timer as time base with adjustable frequency
   clockCycle = timerBegin(1, 8000, true); // set 80 MHz prescaler to 1/10000 sec
-  //timerAttachInterrupt(clockCycle, &CLOCKIRQ, true);
   timerAlarmWrite(clockCycle, 10000, true); // 1000ms
   ESP_LOGI(TAG, "Time base: internal (ESP32 hardware timer)");
   return 1; // success
@@ -60,31 +57,10 @@ void timepulse_start(void) {
 #endif
 }
 
-// helper function to sync systime on start of next second
+// interrupt service routine triggered by either pps or esp32 hardware timer
-int sync_SysTime(time_t t) {
+void IRAM_ATTR CLOCKIRQ(void) {
-  if (sync_TimePulse()) {
+  if (ClockTask != NULL)
-    setTime(t + 1);
+    xTaskNotifyFromISR(ClockTask, xTaskGetTickCountFromISR(), eSetBits, NULL);
-    ESP_LOGD(TAG, "Systime synced on timepulse");
-    return 1; // success
-  } else
-    return 0; // failure
-}
-
-// helper function to sync moment on timepulse
-int sync_TimePulse(void) {
-  // sync on top of next second by timepulse
-  if (xSemaphoreTake(TimePulse, pdMS_TO_TICKS(PPS)) == pdTRUE) {
-    return 1;
-  } // success
-  else
-    ESP_LOGW(TAG, "Missing timepulse, time not synced");
-  return 0; // failure
-}
-
-// interrupt service routine triggered by either rtc pps or esp32 hardware
-// timer
-void IRAM_ATTR CLOCKIRQ() {
-  xTaskNotifyFromISR(ClockTask, xTaskGetTickCountFromISR(), eSetBits, NULL);
 #if defined GPS_INT || defined RTC_INT
   xSemaphoreGiveFromISR(TimePulse, NULL);
   TimePulseTick = !TimePulseTick; // flip ticker
@@ -92,6 +68,31 @@ void IRAM_ATTR CLOCKIRQ() {
   portYIELD_FROM_ISR();
 }
 
+// helper function to sync systime on start of next second
+int sync_SysTime(time_t t) {
+  if (sync_TimePulse() && (t)) { // wait for start of next second by timepulse
+    setTime(t + 1);
+    ESP_LOGD(TAG, "Systime synced on second");
+    return 1; // success
+  } else
+    return 0; // failure
+}
+
+int sync_SysTime(uint32_t t) { // t is epoch seconds starting 1.1.1970
+  return sync_SysTime(static_cast<time_t>(t));
+}
+
+// helper function to sync moment on timepulse
+int sync_TimePulse(void) {
+  // sync on top of next second by timepulse
+  if (xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1100)) == pdTRUE) {
+    return 1;
+  } // success
+  else
+    ESP_LOGW(TAG, "Missing timepulse, time not synced");
+  return 0; // failure
+}
+
 #ifdef HAS_RTC // we have hardware RTC
 
 RtcDS3231<TwoWire> Rtc(Wire); // RTC hardware i2c interface
@@ -153,6 +154,7 @@ int set_rtctime(time_t t) { // t is seconds epoch time starting 1.1.1970
     ESP_LOGI(TAG, "RTC calibrated");
     return 1; // success
   }
+  ESP_LOGE(TAG, "RTC set time failure");
   return 0; // failure
 } // set_rtctime()