diff --git a/include/lorawan.h b/include/lorawan.h
index 3c207c02..cb4158e0 100644
--- a/include/lorawan.h
+++ b/include/lorawan.h
@@ -36,6 +36,9 @@ void lora_send(osjob_t *job);
 void lora_enqueuedata(MessageBuffer_t *message, sendprio_t prio);
 void lora_queuereset(void);
 void lora_housekeeping(void);
+#if (TIME_SYNC_LORAWAN)
 void user_request_network_time_callback(void *pVoidUserUTCTime,
                                         int flagSuccess);
+#endif
+
 #endif
\ No newline at end of file
diff --git a/include/timesync.h b/include/timesync.h
index 9df72171..232ac541 100644
--- a/include/timesync.h
+++ b/include/timesync.h
@@ -14,6 +14,6 @@ void send_timesync_req(void);
 int recv_timesync_ans(uint8_t buf[], uint8_t buf_len);
 void process_timesync_req(void *taskparameter);
 void store_time_sync_req(uint32_t t_millisec);
-int adjustTime(uint32_t t_sec, uint16_t t_msec);
+void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec);
 
 #endif
\ No newline at end of file
diff --git a/platformio.ini b/platformio.ini
index e4421de0..74bc9871 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -31,7 +31,7 @@ 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 = 1.7.41
+release_version = 1.7.422
 ; 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 = 3
diff --git a/src/hal/generic.h b/src/hal/generic.h
index 1151b57f..7511ffff 100644
--- a/src/hal/generic.h
+++ b/src/hal/generic.h
@@ -62,8 +62,8 @@
 //#define HAS_IF482 9600, SERIAL_7E1, GPIO_NUM_12, GPIO_NUM_14 // IF482 serial port parameters
 
 // Settings for DCF77 interface
-#define HAS_DCF77 GPIO_NUM_1
-#define DCF77_ACTIVE_LOW 1
+//#define HAS_DCF77 GPIO_NUM_1
+//#define DCF77_ACTIVE_LOW 1
 
 // Pins for LORA chip SPI interface, reset line and interrupt lines
 #define LORA_SCK  (5) 
diff --git a/src/lmic_config.h b/src/lmic_config.h
index c35cbd19..9e90a439 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -22,7 +22,7 @@
 //#define LMIC_USE_INTERRUPTS 1
 
 //time sync via LoRaWAN network, is not yet supported by TTN (LoRaWAN spec v1.0.3)
-#define LMIC_ENABLE_DeviceTimeReq 1
+//#define LMIC_ENABLE_DeviceTimeReq 1
 
 // 16 μs per tick
 // LMIC requires ticks to be 15.5μs - 100 μs long
diff --git a/src/lorawan.cpp b/src/lorawan.cpp
index 21fe100b..48781d8c 100644
--- a/src/lorawan.cpp
+++ b/src/lorawan.cpp
@@ -462,6 +462,7 @@ void lora_housekeeping(void) {
   // uxTaskGetStackHighWaterMark(LoraTask));
 }
 
+#if (TIME_SYNC_LORAWAN)
 void IRAM_ATTR user_request_network_time_callback(void *pVoidUserUTCTime,
                                                   int flagSuccess) {
   // Explicit conversion from void* to uint32_t* to avoid compiler errors
@@ -504,11 +505,12 @@ void IRAM_ATTR user_request_network_time_callback(void *pVoidUserUTCTime,
   time_t requestDelaySec = osticks2ms(ticksNow - ticksRequestSent) / 1000;
 
   // Update system time with time read from the network
-  adjustTime(*pUserUTCTime + requestDelaySec, 0);
+  setMyTime(*pUserUTCTime + requestDelaySec, 0);
 
   // end of time critical section: release I2C bus
   I2C_MUTEX_UNLOCK();
 
 } // user_request_network_time_callback
+#endif // TIME_SYNC_LORAWAN
 
 #endif // HAS_LORA
diff --git a/src/main.cpp b/src/main.cpp
index 1d0b82f0..4029cd7f 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -411,6 +411,11 @@ void setup() {
 #endif // HAS_BUTTON
 
 #if (TIME_SYNC_INTERVAL)
+#if (!defined(TIME_SYNC_LORAWAN) && !defined(TIME_SYNC_TIMESERVER) &&          \
+     !defined HAS_GPS && !defined HAS_RTC)
+#warning you did not specify a time source, time will not be synched
+#endif
+#else
   // start pps timepulse
   ESP_LOGI(TAG, "Starting Timekeeper...");
   assert(timepulse_init()); // setup timepulse
diff --git a/src/timesync.cpp b/src/timesync.cpp
index bf141814..b38f8c34 100644
--- a/src/timesync.cpp
+++ b/src/timesync.cpp
@@ -130,7 +130,7 @@ void process_timesync_req(void *taskparameter) {
   // calculate fraction milliseconds
   time_to_set_fraction_msec = (uint16_t)(time_offset_ms.count() % 1000);
 
-  adjustTime(time_to_set, time_to_set_fraction_msec);
+  setMyTime(time_to_set, time_to_set_fraction_msec);
 
   // end of time critical section: release I2C bus
   I2C_MUTEX_UNLOCK();
@@ -213,7 +213,7 @@ int recv_timesync_ans(uint8_t buf[], uint8_t buf_len) {
 }
 
 // adjust system time, calibrate RTC and RTC_INT pps
-int IRAM_ATTR adjustTime(uint32_t t_sec, uint16_t t_msec) {
+void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec) {
 
   time_t time_to_set = (time_t)t_sec;