diff --git a/include/display.h b/include/display.h
index d4a873c2..38d503a9 100644
--- a/include/display.h
+++ b/include/display.h
@@ -5,7 +5,6 @@
 #include "cyclic.h"
 
 extern uint8_t DisplayState;
-extern timesource_t timeSource;
 
 extern HAS_DISPLAY u8x8;
 
diff --git a/include/globals.h b/include/globals.h
index 24d34865..72036687 100644
--- a/include/globals.h
+++ b/include/globals.h
@@ -41,13 +41,13 @@
 #define SCREEN_MODE (0x80)
 
 // I2C bus access control
-#define I2C_MUTEX_LOCK()
-xSemaphoreTake(I2Caccess,
-               (3 * DISPLAYREFRESH_MS / portTICK_PERIOD_MS)) == pdTRUE
+#define I2C_MUTEX_LOCK()                                                       \
+  xSemaphoreTake(I2Caccess, (3 * DISPLAYREFRESH_MS / portTICK_PERIOD_MS)) ==   \
+      pdTRUE
 #define I2C_MUTEX_UNLOCK() xSemaphoreGive(I2Caccess)
 
-    // Struct holding devices's runtime configuration
-    typedef struct {
+// Struct holding devices's runtime configuration
+typedef struct {
   uint8_t lorasf;      // 7-12, lora spreadfactor
   uint8_t txpower;     // 2-15, lora tx power
   uint8_t adrmode;     // 0=disabled, 1=enabled
@@ -108,8 +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; // 1sec pps flag set by GPS or RTC
+extern timesource_t timeSource;
 extern hw_timer_t *sendCycle, *displaytimer, *clockCycle;
 extern SemaphoreHandle_t I2Caccess, TimePulse;
 extern TaskHandle_t irqHandlerTask, ClockTask;
diff --git a/include/gpsread.h b/include/gpsread.h
index e96e2531..62eb1a15 100644
--- a/include/gpsread.h
+++ b/include/gpsread.h
@@ -9,10 +9,14 @@
 #include <Wire.h>
 #endif
 
+#define NMEA_FRAME_SIZE 80 // NEMA has a maxium of 80 bytes per record
+#define NMEA_BUFFERTIME 50 // 50ms safety time regardless
+
 extern TinyGPSPlus gps; // Make TinyGPS++ instance globally availabe
 extern gpsStatus_t
     gps_status; // Make struct for storing gps data globally available
 extern TaskHandle_t GpsTask;
+extern TickType_t const gpsDelay_ticks; // time to NMEA arrival
 
 int gps_init(void);
 void gps_read(void);
diff --git a/include/irqhandler.h b/include/irqhandler.h
index cc8d15ac..64cb12fe 100644
--- a/include/irqhandler.h
+++ b/include/irqhandler.h
@@ -9,6 +9,7 @@
 #include "globals.h"
 #include "cyclic.h"
 #include "senddata.h"
+#include "timekeeper.h"
 
 void irqHandler(void *pvParameters);
 void IRAM_ATTR homeCycleIRQ();
diff --git a/include/payload.h b/include/payload.h
index d8fe468b..159dcfc4 100644
--- a/include/payload.h
+++ b/include/payload.h
@@ -1,7 +1,8 @@
 #ifndef _PAYLOAD_H_
 #define _PAYLOAD_H_
 
-// MyDevices CayenneLPP channels for dynamic sensor payload format
+// MyDevices CayenneLPP 1.0 channels for Synamic sensor payload format
+// all payload goes out on LoRa FPort 1
 #if (PAYLOAD_ENCODER == 3)
 
 #define LPP_GPS_CHANNEL 20
@@ -19,7 +20,7 @@
 
 #endif
 
-// MyDevices CayenneLPP types
+// MyDevices CayenneLPP 2.0 types for Packed Sensor Payload, not using channels, but different FPorts
 #define LPP_GPS 136          // 3 byte lon/lat 0.0001 °, 3 bytes alt 0.01m
 #define LPP_TEMPERATURE 103  // 2 bytes, 0.1°C signed MSB
 #define LPP_DIGITAL_INPUT 0  // 1 byte
diff --git a/include/timekeeper.h b/include/timekeeper.h
index b4afb1b7..ae58df3d 100644
--- a/include/timekeeper.h
+++ b/include/timekeeper.h
@@ -18,7 +18,7 @@ extern const char timeSetSymbols[];
 void IRAM_ATTR CLOCKIRQ(void);
 void clock_init(void);
 void clock_loop(void *pvParameters);
-time_t time_sync(void);
+void timeSync(void);
 void timepulse_start(void);
 uint8_t timepulse_init(void);
 time_t TimeIsValid(time_t const t);
diff --git a/src/cyclic.cpp b/src/cyclic.cpp
index 3d170eb1..c9341f03 100644
--- a/src/cyclic.cpp
+++ b/src/cyclic.cpp
@@ -5,7 +5,7 @@
 #include "cyclic.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 // do all housekeeping
 void doHousekeeping() {
@@ -17,8 +17,12 @@ void doHousekeeping() {
   if (cfg.runmode == 1)
     do_reset();
 
+#ifdef HAS_SPI
   spi_housekeeping();
+#endif
+#ifdef HAS_LORA
   lora_housekeeping();
+#endif
 
   // task storage debugging //
   ESP_LOGD(TAG, "IRQhandler %d bytes left | Taskstate = %d",
diff --git a/src/dcf77.cpp b/src/dcf77.cpp
index be5a1b0b..1c27235e 100644
--- a/src/dcf77.cpp
+++ b/src/dcf77.cpp
@@ -14,7 +14,7 @@ https://github.com/udoklein/dcf77
 #include "dcf77.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 // triggered by second timepulse to ticker out DCF signal
 void DCF77_Pulse(time_t t, uint8_t const *DCFpulse) {
diff --git a/src/display.cpp b/src/display.cpp
index d5e2b382..047c233e 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -46,7 +46,6 @@ const char *printmonth[] = {"xxx", "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                             "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 
 uint8_t DisplayState = 0;
-timesource_t timeSource = _unsynced;
 
 // helper function, prints a hex key on display
 void DisplayKey(const uint8_t *key, uint8_t len, bool lsb) {
diff --git a/src/gpsread.cpp b/src/gpsread.cpp
index 2ef5d84d..9c34049d 100644
--- a/src/gpsread.cpp
+++ b/src/gpsread.cpp
@@ -3,7 +3,7 @@
 #include "globals.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 TinyGPSPlus gps;
 gpsStatus_t gps_status;
@@ -11,6 +11,10 @@ TaskHandle_t GpsTask;
 
 #ifdef GPS_SERIAL
 HardwareSerial GPS_Serial(1); // use UART #1
+TickType_t const gpsDelay_ticks = pdMS_TO_TICKS(1000 - NMEA_BUFFERTIME) -
+                                  tx_Ticks(NMEA_FRAME_SIZE, GPS_SERIAL);
+#else
+TickType_t const gpsDelay_ticks = pdMS_TO_TICKS(1000 - NMEA_BUFFERTIME);
 #endif
 
 // initialize and configure GPS
@@ -23,6 +27,13 @@ int gps_init(void) {
     return 0;
   }
 
+// set timeout for reading recent time from GPS
+#ifdef GPS_SERIAL // serial GPS
+
+#else // I2C GPS
+
+#endif
+
 #if defined GPS_SERIAL
   GPS_Serial.begin(GPS_SERIAL);
   ESP_LOGI(TAG, "Using serial GPS");
@@ -76,20 +87,12 @@ 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
+  // set time to wait for arrive next recent NMEA time record
+  static const uint32_t gpsDelay_ms = gpsDelay_ticks / portTICK_PERIOD_MS;
 
   time_t t = 0;
 
-// 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())) {
+  if ((gps.time.age() < gpsDelay_ms) && (gps.time.isValid())) {
 
     ESP_LOGD(TAG, "GPS time age: %dms, is valid: %s", gps.time.age(),
              gps.time.isValid() ? "yes" : "no");
diff --git a/src/if482.cpp b/src/if482.cpp
index a0d93182..a532fdaa 100644
--- a/src/if482.cpp
+++ b/src/if482.cpp
@@ -82,19 +82,19 @@ not evaluated by model BU-190
 #include "if482.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 HardwareSerial IF482(2); // use UART #2 (note: #1 may be in use for serial GPS)
 
-// triggered by timepulse to ticker out DCF signal
+// triggered by timepulse to send IF482 signal
 void IF482_Pulse(time_t t) {
 
   static const TickType_t txDelay =
       pdMS_TO_TICKS(IF482_PULSE_LENGTH - tx_Ticks(IF482_FRAME_SIZE, HAS_IF482));
 
-  TickType_t startTime = xTaskGetTickCount();
-
-  vTaskDelayUntil(&startTime, txDelay); // wait until moment to fire
+  //TickType_t startTime = xTaskGetTickCount();
+  //vTaskDelayUntil(&startTime, txDelay); // wait until moment to fire
+  vTaskDelay(txDelay); // wait until moment to fire
   IF482.print(IF482_Frame(t + 1)); // note: if482 telegram for *next* second
 }
 
diff --git a/src/irqhandler.cpp b/src/irqhandler.cpp
index 3f680702..1236225c 100644
--- a/src/irqhandler.cpp
+++ b/src/irqhandler.cpp
@@ -1,7 +1,7 @@
 #include "irqhandler.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 // irq handler task, handles all our application level interrupts
 void irqHandler(void *pvParameters) {
@@ -12,11 +12,10 @@ void irqHandler(void *pvParameters) {
 
   // task remains in blocked state until it is notified by an irq
   for (;;) {
-    xTaskNotifyWait(
-        0x00,             // Don't clear any bits on entry
-        ULONG_MAX,        // Clear all bits on exit
-        &InterruptStatus, // Receives the notification value
-        portMAX_DELAY);   // wait forever
+    xTaskNotifyWait(0x00,             // Don't clear any bits on entry
+                    ULONG_MAX,        // Clear all bits on exit
+                    &InterruptStatus, // Receives the notification value
+                    portMAX_DELAY);   // wait forever
 
 // button pressed?
 #ifdef HAS_BUTTON
@@ -31,8 +30,10 @@ void irqHandler(void *pvParameters) {
 #endif
 
     // are cyclic tasks due?
-    if (InterruptStatus & CYCLIC_IRQ)
+    if (InterruptStatus & CYCLIC_IRQ) {
       doHousekeeping();
+      timeSync();
+    }
 
     // is time to send the payload?
     if (InterruptStatus & SENDCOUNTER_IRQ)
diff --git a/src/lorawan.cpp b/src/lorawan.cpp
index 36ffa3ad..df73da4f 100644
--- a/src/lorawan.cpp
+++ b/src/lorawan.cpp
@@ -358,12 +358,7 @@ void lora_send(osjob_t *job) {
                       lora_send);
 }
 
-#endif // HAS_LORA
-
 esp_err_t lora_stack_init() {
-#ifndef HAS_LORA
-  return ESP_OK; // continue main program
-#else
   assert(SEND_QUEUE_SIZE);
   LoraSendQueue = xQueueCreate(SEND_QUEUE_SIZE, sizeof(MessageBuffer_t));
   if (LoraSendQueue == 0) {
@@ -401,12 +396,10 @@ esp_err_t lora_stack_init() {
   }
 
   return ESP_OK; // continue main program
-#endif // HAS_LORA
 }
 
 void lora_enqueuedata(MessageBuffer_t *message, sendprio_t prio) {
   // enqueue message in LORA send queue
-#ifdef HAS_LORA
   BaseType_t ret;
   switch (prio) {
   case prio_high:
@@ -423,27 +416,26 @@ void lora_enqueuedata(MessageBuffer_t *message, sendprio_t prio) {
   } else {
     ESP_LOGW(TAG, "LORA sendqueue is full");
   }
-#endif
 }
 
-void lora_queuereset(void) {
-#ifdef HAS_LORA
-  xQueueReset(LoraSendQueue);
-#endif
-}
+void lora_queuereset(void) { xQueueReset(LoraSendQueue); }
 
 void lora_housekeeping(void) {
-#ifdef HAS_LORA
-// ESP_LOGD(TAG, "loraloop %d bytes left",
-// uxTaskGetStackHighWaterMark(LoraTask));
-#endif
+  // ESP_LOGD(TAG, "loraloop %d bytes left",
+  // uxTaskGetStackHighWaterMark(LoraTask));
 }
 
 void user_request_network_time_callback(void *pVoidUserUTCTime,
                                         int flagSuccess) {
-#ifdef HAS_LORA
   // Explicit conversion from void* to uint32_t* to avoid compiler errors
   time_t *pUserUTCTime = (time_t *)pVoidUserUTCTime;
+
+  // A struct that will be populated by LMIC_getNetworkTimeReference.
+  // It contains the following fields:
+  //  - tLocal: the value returned by os_GetTime() when the time
+  //            request was sent to the gateway, and
+  //  - tNetwork: the seconds between the GPS epoch and the time
+  //              the gateway received the time request
   lmic_time_reference_t lmicTimeReference;
 
   if (flagSuccess != 1) {
@@ -473,11 +465,12 @@ void user_request_network_time_callback(void *pVoidUserUTCTime,
 
   // Update system time with time read from the network
   if (TimeIsValid(*pUserUTCTime)) {
-    setTime(*pUserUTCTime);
+    xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
+    setTime(*pUserUTCTime + 1);
     timeSource = _lora;
     ESP_LOGI(TAG, "Received recent time from LoRa");
-    }
-  else
+  } else
     ESP_LOGI(TAG, "Invalid time received from LoRa");
-#endif // HAS_LORA
-} // user_request_network_time_callback
\ No newline at end of file
+} // user_request_network_time_callback
+
+#endif // HAS_LORA
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index a2a807ab..eb04d063 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -52,7 +52,7 @@ ESP32 hardware irq timers
 
  RTC hardware timer (if present)
 ================================
- triggers IF482 clock signal
+ triggers pps 1 sec impulse
 
 */
 
@@ -72,6 +72,7 @@ TaskHandle_t irqHandlerTask, ClockTask;
 SemaphoreHandle_t I2Caccess, TimePulse;
 bool volatile TimePulseTick = false;
 time_t userUTCTime = 0;
+timesource_t timeSource = _unsynced;
 
 // container holding unique MAC address hashes with Memory Alloctor using PSRAM,
 // if present
@@ -86,7 +87,7 @@ TimeChangeRule mySTD = STANDARD_TIME;
 Timezone myTZ(myDST, mySTD);
 
 // local Tag for logging
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 void setup() {
 
@@ -283,14 +284,14 @@ void setup() {
 // initialize LoRa
 #ifdef HAS_LORA
   strcat_P(features, " LORA");
-#endif
   assert(lora_stack_init() == ESP_OK);
+#endif
 
 // initialize SPI
 #ifdef HAS_SPI
   strcat_P(features, " SPI");
-#endif
   assert(spi_init() == ESP_OK);
+#endif
 
 #ifdef VENDORFILTER
   strcat_P(features, " OUIFLT");
@@ -361,10 +362,7 @@ void setup() {
   ESP_LOGI(TAG, "Starting Timekeeper...");
   assert(timepulse_init()); // setup timepulse
   timepulse_start();
-#ifdef TIME_SYNC_INTERVAL
-  setSyncInterval(TIME_SYNC_INTERVAL * 60); // controls timeStatus() via Time.h
-  setSyncProvider(time_sync); // is called by Time.h
-#endif
+  timeSync();
 
   // start wifi in monitor mode and start channel rotation timer
   ESP_LOGI(TAG, "Starting Wifi...");
diff --git a/src/rtctime.cpp b/src/rtctime.cpp
index 730d4d98..bea2f277 100644
--- a/src/rtctime.cpp
+++ b/src/rtctime.cpp
@@ -1,7 +1,7 @@
 #include "rtctime.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 #ifdef HAS_RTC // we have hardware RTC
 
diff --git a/src/timekeeper.cpp b/src/timekeeper.cpp
index 5a1bcae1..c1a54de1 100644
--- a/src/timekeeper.cpp
+++ b/src/timekeeper.cpp
@@ -1,57 +1,64 @@
 #include "timekeeper.h"
 
 // Local logging tag
-static const char TAG[] = "main";
+static const char TAG[] = __FILE__;
 
 // symbol to display current time source
 const char timeSetSymbols[] = {'G', 'R', 'L', '?'};
 
 getExternalTime TimeSourcePtr; // pointer to time source function
 
-time_t time_sync() {
-  // check synchonization of systime, called by cyclic.cpp
+
+// syncs systime from external time source and sets/reads RTC, called by
+// cyclic.cpp
+void timeSync(void) {
 
   time_t t = 0;
 
 #ifdef HAS_GPS
-  xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
-  ESP_LOGD(TAG, "micros = %d", micros());
-  t = get_gpstime();
-  if (t) {
-    t++; // gps time concerns past second, so we add one second
+    // do we have a valid GPS time?
+    if (get_gpstime()) { // then let's sync GPS time on top of second
+
+      xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
+      vTaskDelay(gpsDelay_ticks);
+      t = get_gpstime(); // fetch time from recent NEMA record
+      if (t) {
+        t++; // gps time concerns past second, so we add one
+        xSemaphoreTake(TimePulse, pdMS_TO_TICKS(1000)); // wait for pps
+        setTime(t);
 #ifdef HAS_RTC
-    set_rtctime(t); // calibrate RTC
+        set_rtctime(t); // calibrate RTC
 #endif
-    timeSource = _gps;
-    goto exit;
-  }
+        timeSource = _gps;
+        goto exit;
+      }
+    }
 #endif
 
 // no GPS -> fallback to RTC time while trying lora sync
 #ifdef HAS_RTC
-  t = get_rtctime();
-  if (t)
-    timeSource = _rtc;
-  else
-    ESP_LOGW(TAG, "no confident RTC time");
+    t = get_rtctime();
+    if (t) {
+      setTime(t);
+      timeSource = _rtc;
+    } else
+      ESP_LOGW(TAG, "no confident RTC time");
 #endif
 
 // try lora sync if we have
 #if defined HAS_LORA && defined TIME_SYNC_LORA
-  LMIC_requestNetworkTime(user_request_network_time_callback, &userUTCTime);
+    LMIC_requestNetworkTime(user_request_network_time_callback, &userUTCTime);
 #endif
 
 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;
+    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;
 
-} // time_sync()
+} // timeSync()
 
 // helper function to setup a pulse per second for time synchronisation
 uint8_t timepulse_init() {
@@ -119,8 +126,6 @@ void IRAM_ATTR CLOCKIRQ(void) {
 // helper function to check plausibility of a time
 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() ? t : 0);
 }