time accuracy improvement

include/globals.h

@@ -112,7 +112,7 @@ extern uint16_t volatile macs_total, macs_wifi, macs_ble,
 extern bool volatile TimePulseTick; // 1sec pps flag set by GPS or RTC
 extern timesource_t timeSource;
 extern hw_timer_t *displayIRQ, *ppsIRQ;
-extern SemaphoreHandle_t I2Caccess, TimePulse;
+extern SemaphoreHandle_t I2Caccess;
 extern TaskHandle_t irqHandlerTask, ClockTask;
 extern TimerHandle_t WifiChanTimer;
 extern Timezone myTZ;

src/lorawan.cpp

@@ -498,6 +498,6 @@ void user_request_network_time_callback(void *pVoidUserUTCTime,
       ESP_LOGI(TAG, "Received recent time from LoRa");
     } else
       ESP_LOGI(TAG, "Invalid time received from LoRa");
-} // user_request_network_time_callback
+  } // user_request_network_time_callback
 
 #endif // HAS_LORA

src/main.cpp

@@ -84,7 +84,7 @@ uint16_t volatile macs_total = 0, macs_wifi = 0, macs_ble = 0,
 hw_timer_t *ppsIRQ = NULL, *displayIRQ = NULL;
 
 TaskHandle_t irqHandlerTask, ClockTask;
-SemaphoreHandle_t I2Caccess, TimePulse;
+SemaphoreHandle_t I2Caccess;
 bool volatile TimePulseTick = false;
 time_t userUTCTime = 0;
 timesource_t timeSource = _unsynced;
@@ -113,8 +113,6 @@ void setup() {
   if (I2Caccess)
     xSemaphoreGive(I2Caccess); // Flag the i2c bus available for use
 
-  TimePulse = xSemaphoreCreateBinary(); // as signal that shows time pulse flip
-
   // disable brownout detection
 #ifdef DISABLE_BROWNOUT
   // register with brownout is at address DR_REG_RTCCNTL_BASE + 0xd4

src/rtctime.cpp

@@ -49,6 +49,10 @@ uint8_t rtc_init(void) {
 uint8_t set_rtctime(time_t t) { // t is UTC in seconds epoch time
   if (I2C_MUTEX_LOCK()) {
     Rtc.SetDateTime(RtcDateTime(t - SECS_YR_2000)); // epoch -> sec2000
+#ifdef RTC_INT // sync rtc 1Hz pulse on top of second
+    Rtc.SetSquareWavePin(DS3231SquareWavePin_ModeNone); // off
+    Rtc.SetSquareWavePin(DS3231SquareWavePin_ModeClock); // start
+#endif
     I2C_MUTEX_UNLOCK();
     ESP_LOGI(TAG, "RTC time synced");
     return 1; // success

src/timekeeper.cpp

@@ -124,7 +124,6 @@ void IRAM_ATTR CLOCKIRQ(void) {
                        &xHigherPriorityTaskWoken);
 
 #if defined GPS_INT || defined RTC_INT
-  xSemaphoreGiveFromISR(TimePulse, &xHigherPriorityTaskWoken);
   TimePulseTick = !TimePulseTick; // flip ticker
 #endif
 

src/timesync.cpp

@@ -109,10 +109,14 @@ void process_timesync_req(void *taskparameter) {
         // wait until next cycle
         vTaskDelay(pdMS_TO_TICKS(TIME_SYNC_CYCLE * 1000));
       } else {
-        // send flush to open a receive window for last time_sync_ans
-        payload.reset();
-        payload.addByte(0x99);
-        SendPayload(RCMDPORT, prio_high);
+        // send flush to open a receive window for last time_sync_answer
+        // payload.reset();
+        // payload.addByte(0x99);
+        // SendPayload(RCMDPORT, prio_high);
+
+        // Send a payload-less message to open a receive window for last
+        // time_sync_answer
+        void LMIC_sendAlive();
       }
     }
   } // for
@@ -145,13 +149,15 @@ void process_timesync_req(void *taskparameter) {
       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)
       // sync timer pps to top of second
-      if (ppsIRQ) {
       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
 
-      setTime(++time_to_set); // +1 sec after waiting for top of seceond
 #ifdef HAS_RTC
       set_rtctime(time_to_set); // calibrate RTC if we have one
 #endif
@@ -162,8 +168,7 @@ void process_timesync_req(void *taskparameter) {
       ESP_LOGI(TAG, "[%0.3f] Timesync finished, time adjusted by %.3f sec",
                millis() / 1000.0, myClock_secTick(time_offset).count());
     } else
-      ESP_LOGI(TAG,
-               "[%0.3f] Timesync finished, time is up to date",
+      ESP_LOGI(TAG, "[%0.3f] Timesync finished, time is up to date",
                millis() / 1000.0);
   } else
     ESP_LOGW(TAG, "[%0.3f] Timesync failed, outdated time calculated",
@@ -212,9 +217,9 @@ int recv_timesync_ans(uint8_t buf[], uint8_t buf_len) {
     uint16_t timestamp_msec; // convert 1/250th sec fractions to ms
     uint32_t timestamp_sec;
 
-    // fetch timeserver time from 4 bytes containing the UTC seconds since unix
-    // epoch. Octet order is big endian. Casts are necessary, because buf is an
-    // array of single byte values, and they might overflow when shifted
+    // fetch timeserver time from 4 bytes containing the UTC seconds since
+    // unix epoch. Octet order is big endian. Casts are necessary, because buf
+    // is an array of single byte values, and they might overflow when shifted
     timestamp_sec = ((uint32_t)buf[4]) | (((uint32_t)buf[3]) << 8) |
                     (((uint32_t)buf[2]) << 16) | (((uint32_t)buf[1]) << 24);