interrupt timing issues (not fully solved yet)

include/if482.h

@@ -2,13 +2,9 @@
 #define _IF482_H
 
 #include "globals.h"
-#include "timekeeper.h"
 
 #define IF482_FRAME_SIZE (17)
 
-extern HardwareSerial IF482;
-
-void IF482_Pulse(time_t t);
 String IRAM_ATTR IF482_Frame(time_t tt);
 
 #endif

include/timekeeper.h

@@ -6,9 +6,10 @@
 #include "TimeLib.h"
 #include "irqhandler.h"
 
-#if(HAS_GPS)
+#ifdef HAS_GPS
 #include "gpsread.h"
 #endif
+
 #ifdef HAS_IF482
 #include "if482.h"
 #elif defined HAS_DCF77

src/if482.cpp

@@ -84,18 +84,6 @@ not evaluated by model BU-190, use "F" instead for this model
 // Local logging tag
 static const char TAG[] = __FILE__;
 
-HardwareSerial IF482(2); // use UART #2 (note: #1 may be in use for serial GPS)
-
-// triggered by timepulse to send IF482 signal
-void IF482_Pulse(time_t t) {
-
-  static const TickType_t txDelay =
-      pdMS_TO_TICKS(1000) - tx_Ticks(IF482_FRAME_SIZE, HAS_IF482);
-
-  vTaskDelay(txDelay);             // wait until moment to fire
-  IF482.print(IF482_Frame(t + 1)); // note: if482 telegram for *next* second
-}
-
 String IRAM_ATTR IF482_Frame(time_t printTime) {
 
   time_t t = myTZ.toLocal(printTime);

src/irqhandler.cpp

@@ -3,6 +3,8 @@
 // Local logging tag
 static const char TAG[] = __FILE__;
 
+static portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
+
 // irq handler task, handles all our application level interrupts
 void irqHandler(void *pvParameters) {
 
@@ -54,12 +56,13 @@ void irqHandler(void *pvParameters) {
 
 #ifdef HAS_DISPLAY
 void IRAM_ATTR DisplayIRQ() {
+  portENTER_CRITICAL_ISR(&mux);
   BaseType_t xHigherPriorityTaskWoken;
   xHigherPriorityTaskWoken = pdFALSE;
 
   xTaskNotifyFromISR(irqHandlerTask, DISPLAY_IRQ, eSetBits,
                      &xHigherPriorityTaskWoken);
-
+  portEXIT_CRITICAL_ISR(&mux);
   if (xHigherPriorityTaskWoken)
     portYIELD_FROM_ISR();
 }
@@ -67,11 +70,13 @@ void IRAM_ATTR DisplayIRQ() {
 
 #ifdef HAS_BUTTON
 void IRAM_ATTR ButtonIRQ() {
+  portENTER_CRITICAL_ISR(&mux);
   BaseType_t xHigherPriorityTaskWoken;
   xHigherPriorityTaskWoken = pdFALSE;
 
   xTaskNotifyFromISR(irqHandlerTask, BUTTON_IRQ, eSetBits,
                      &xHigherPriorityTaskWoken);
+  portEXIT_CRITICAL_ISR(&mux);
 
   if (xHigherPriorityTaskWoken)
     portYIELD_FROM_ISR();

src/main.cpp

@@ -36,7 +36,7 @@ looptask      1     1     arduino core -> runs the LMIC LoRa stack
 irqhandler    1     1     executes tasks triggered by timer irq
 gpsloop       1     2     reads data from GPS via serial or i2c
 bmeloop       1     1     reads data from BME sensor via i2c
-timesync_req  1     4     temporary task for processing time sync requests
+timesync_req  1     2     temporary task for processing time sync requests
 IDLE          1     0     ESP32 arduino scheduler -> runs wifi channel rotator
 
 Low priority numbers denote low priority tasks.

src/timekeeper.cpp

@@ -14,8 +14,14 @@ static const char TAG[] = __FILE__;
 // symbol to display current time source
 const char timeSetSymbols[] = {'G', 'R', 'L', '?'};
 
+#ifdef HAS_IF482
+HardwareSerial IF482(2); // use UART #2 (#1 may be in use for serial GPS)
+#endif
+
 Ticker timesyncer;
 
+static portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
+
 void timeSync() { xTaskNotify(irqHandlerTask, TIMESYNC_IRQ, eSetBits); }
 
 time_t timeProvider(void) {
@@ -115,18 +121,22 @@ void timepulse_start(void) {
 // interrupt service routine triggered by either pps or esp32 hardware timer
 void IRAM_ATTR CLOCKIRQ(void) {
 
+  portENTER_CRITICAL_ISR(&mux);
   BaseType_t xHigherPriorityTaskWoken;
-  SyncToPPS(); // calibrates UTC systime, see microTime.h
   xHigherPriorityTaskWoken = pdFALSE;
 
+  SyncToPPS(); // calibrates UTC systime, see microTime.h
+
   if (ClockTask != NULL)
     xTaskNotifyFromISR(ClockTask, uint32_t(now()), eSetBits,
                        &xHigherPriorityTaskWoken);
 
-#if defined GPS_INT || defined RTC_INT
+#if (defined GPS_INT || defined RTC_INT)
-  TimePulseTick = !TimePulseTick; // flip ticker
+  TimePulseTick = !TimePulseTick; // flip pulse ticker
 #endif
 
+  portEXIT_CRITICAL_ISR(&mux);
+
   // yield only if we should
   if (xHigherPriorityTaskWoken)
     portYIELD_FROM_ISR();
@@ -163,8 +173,8 @@ TickType_t tx_Ticks(uint32_t framesize, unsigned long baud, uint32_t config,
 
   uint32_t databits = ((config & 0x0c) >> 2) + 5;
   uint32_t stopbits = ((config & 0x20) >> 5) + 1;
-  uint32_t txTime = (databits + stopbits + 2) * framesize * 1000.0 / baud;
+  uint32_t txTime = (databits + stopbits + 1) * framesize * 1000.0 / baud;
-  // +1 ms margin for the startbit +1 ms for pending processing time
+  // +1 for the startbit
 
   return round(txTime);
 }
@@ -207,10 +217,13 @@ void clock_loop(void *taskparameter) { // ClockTask
   uint32_t printtime;
   time_t t = *((time_t *)taskparameter); // UTC time seconds
 
-  // preload first DCF frame before start
 #ifdef HAS_DCF77
-  uint8_t *DCFpulse; // pointer on array with DCF pulse bits
+  uint8_t *DCFpulse;                  // pointer on array with DCF pulse bits
-  DCFpulse = DCF77_Frame(nextmin(t));
+  DCFpulse = DCF77_Frame(nextmin(t)); // load first DCF frame before start
+#elif defined HAS_IF482
+  static TickType_t txDelay =
+      pdMS_TO_TICKS(1000 - 2) - tx_Ticks(IF482_FRAME_SIZE, HAS_IF482);
+  // 2ms margin for processing time
 #endif
 
   // output the next second's pulse after timepulse arrived
@@ -226,7 +239,8 @@ void clock_loop(void *taskparameter) { // ClockTask
 
 #if defined HAS_IF482
 
-    IF482_Pulse(t);
+    vTaskDelay(txDelay);             // wait until moment to fire
+    IF482.print(IF482_Frame(t + 1)); // note: if482 telegram for *next* second
 
 #elif defined HAS_DCF77
 

src/timesync.cpp

@@ -54,7 +54,7 @@ void send_timesync_req() {
                               "timesync_req",       // name of task
                               2048,                 // stack size of task
                               (void *)1,            // task parameter
-                              4,                    // priority of the task
+                              2,                    // priority of the task
                               &timeSyncReqTask,     // task handle
                               1);                   // CPU core
   }
@@ -129,10 +129,14 @@ void process_timesync_req(void *taskparameter) {
   // calculate absolute time offset with millisecond precision using time base
   // of LMIC os, since we use LMIC's ostime_t txEnd as tx timestamp
   time_offset += milliseconds(osticks2ms(os_getTime()));
+
   // apply calibration factor for processing time
   time_offset += milliseconds(TIME_SYNC_FIXUP);
-  // convert to seconds
+  // convert to whole seconds
   time_to_set = static_cast<time_t>(myClock_secTick(time_offset).count());
+  // time_to_set =
+  // static_cast<time_t>(duration_cast<seconds>(time_offset).count());
+
   // calculate fraction milliseconds
   time_to_set_fraction_msec = static_cast<uint16_t>(time_offset.count() % 1000);
 
@@ -145,15 +149,14 @@ void process_timesync_req(void *taskparameter) {
         TIME_SYNC_TRIGGER) { // milliseconds threshold
 
       // wait until top of second
-      uint16_t const wait_ms = 1000 - time_to_set_fraction_msec;
+      vTaskDelay(pdMS_TO_TICKS(1000 - time_to_set_fraction_msec));
-      ESP_LOGD(TAG, "[%0.3f] waiting %d ms", millis() / 1000.0, wait_ms);
-      vTaskDelay(pdMS_TO_TICKS(wait_ms));
 
-#if !defined(GPS_INT) && !defined(RTC_INT)
+      time_to_set++; // advance time the one waited second
+
+#if (!defined GPS_INT && !defined RTC_INT)
       // sync esp32 hardware timer based pps to top of second
       timerRestart(ppsIRQ); // reset pps timer
       CLOCKIRQ();           // fire clock pps interrupt
-      time_to_set++;        // advance time 1 second
 #endif
 
       setTime(time_to_set); // set the time on top of second
@@ -193,6 +196,21 @@ void store_time_sync_req(uint32_t t_txEnd_ms) {
            t_txEnd_ms % 1000);
 }
 
+/*
+// called from lorawan.cpp after time_sync_req was sent
+void store_time_sync_req_pwm(void) {
+
+  uint8_t k = time_sync_seqNo % TIME_SYNC_SAMPLES;
+
+  time_sync_tx[k] += milliseconds(t_txEnd_ms);
+
+  ESP_LOGD(TAG, "[%0.3f] Timesync request #%d sent at %d.%03d",
+           millis() / 1000.0, time_sync_seqNo, t_txEnd_ms / 1000,
+           t_txEnd_ms % 1000);
+}
+*/
+
+
 // process timeserver timestamp answer, called from lorawan.cpp
 int recv_timesync_ans(uint8_t buf[], uint8_t buf_len) {
 
@@ -229,7 +247,7 @@ int recv_timesync_ans(uint8_t buf[], uint8_t buf_len) {
     // construct the timepoint when message was seen on gateway
     time_sync_rx[k] += seconds(timestamp_sec) + milliseconds(timestamp_msec);
 
-    // guess if the timepoint is recent by comparing with code compile date
+    // guess timepoint is recent if newer than code compile date
     if (timeIsValid(myClock::to_time_t(time_sync_rx[k]))) {
       ESP_LOGD(TAG, "[%0.3f] Timesync request #%d rcvd at %d.%03d",
                millis() / 1000.0, seq_no, timestamp_sec, timestamp_msec);