diff --git a/core/MySensorsCore.cpp b/core/MySensorsCore.cpp
index eb999ad..678b66e 100644
--- a/core/MySensorsCore.cpp
+++ b/core/MySensorsCore.cpp
@@ -686,7 +686,7 @@ void _nodeLock(const char* str)
 		CORE_DEBUG(PSTR("MCO:NLK:TSL\n"));	// sleep transport
 #endif
 		setIndication(INDICATION_SLEEP);
-		(void)hwSleep((unsigned long)1000*60*30); // Sleep for 30 min before resending LOCKED message
+		(void)hwSleep((uint32_t)1000*60*30); // Sleep for 30 min before resending LOCKED message
 		setIndication(INDICATION_WAKEUP);
 	}
 #else
@@ -702,7 +702,7 @@ void _checkNodeLock(void)
 		// Node is locked, check if unlock pin is asserted, else hang the node
 		hwPinMode(MY_NODE_UNLOCK_PIN, INPUT_PULLUP);
 		// Make a short delay so we are sure any large external nets are fully pulled
-		unsigned long enter = hwMillis();
+		uint32_t enter = hwMillis();
 		while (hwMillis() - enter < 2) {}
 		if (hwDigitalRead(MY_NODE_UNLOCK_PIN) == 0) {
 			// Pin is grounded, reset lock counter
diff --git a/core/MySensorsCore.h b/core/MySensorsCore.h
index 78bcfbe..3008e28 100644
--- a/core/MySensorsCore.h
+++ b/core/MySensorsCore.h
@@ -411,7 +411,7 @@ void receive(const MyMessage &message)  __attribute__((weak));
 /**
 * @brief Callback for incoming time messages
 */
-void receiveTime(unsigned long)  __attribute__((weak));
+void receiveTime(uint32_t)  __attribute__((weak));
 /**
 * @brief Node presenation
 */
diff --git a/hal/architecture/MyHw.h b/hal/architecture/MyHw.h
index 3fd9c36..cd45a54 100644
--- a/hal/architecture/MyHw.h
+++ b/hal/architecture/MyHw.h
@@ -65,7 +65,7 @@ typedef uint8_t unique_id_t[16];
  * @param ms         Time to sleep, in [ms].
  * @return MY_WAKE_UP_BY_TIMER.
  */
-int8_t hwSleep(unsigned long ms);
+int8_t hwSleep(uint32_t ms);
 
 /**
  * Sleep for a defined time, using minimum power, or until woken by interrupt.
@@ -74,7 +74,7 @@ int8_t hwSleep(unsigned long ms);
  * @param ms         Time to sleep, in [ms].
  * @return MY_WAKE_UP_BY_TIMER when woken by timer, or interrupt number when woken by interrupt.
  */
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms);
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms);
 
 /**
  * Sleep for a defined time, using minimum power, or until woken by one of the interrupts.
@@ -86,7 +86,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms);
  * @return MY_WAKE_UP_BY_TIMER when woken by timer, or interrupt number when woken by interrupt.
  */
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms);
+               uint32_t ms);
 
 /**
 * Retrieve unique hardware ID
diff --git a/hal/architecture/MyHwAVR.cpp b/hal/architecture/MyHwAVR.cpp
index b23cbf8..b862f92 100644
--- a/hal/architecture/MyHwAVR.cpp
+++ b/hal/architecture/MyHwAVR.cpp
@@ -119,7 +119,7 @@ void hwPowerDown(const uint8_t wdto)
 	ADCSRA |= (1 << ADEN);
 }
 
-void hwInternalSleep(unsigned long ms)
+void hwInternalSleep(uint32_t ms)
 {
 	// Sleeping with watchdog only supports multiples of 16ms.
 	// Round up to next multiple of 16ms, to assure we sleep at least the
@@ -138,19 +138,19 @@ void hwInternalSleep(unsigned long ms)
 	}
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	hwInternalSleep(ms);
 	return MY_WAKE_UP_BY_TIMER;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	return hwSleep(interrupt,mode,INVALID_INTERRUPT_NUM,0u,ms);
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	// ATMega328P supports following modes to wake from sleep: LOW, CHANGE, RISING, FALLING
 	// Datasheet states only LOW can be used with INT0/1 to wake from sleep, which is incorrect.
@@ -208,9 +208,9 @@ inline void hwRandomNumberInit()
 	// This function initializes the random number generator with a seed
 	// of 32 bits.  This method is good enough to earn FIPS 140-2 conform
 	// random data. This should reach to generate 32 Bit for randomSeed().
-	unsigned long seed = 0;
-	unsigned long start = millis();
-	unsigned long timeout = start + 20;
+	uint32_t seed = 0;
+	uint32_t start = millis();
+	uint32_t timeout = start + 20;
 
 	// Trigger floating effect of an unconnected pin
 	pinMode(MY_SIGNING_SOFT_RANDOMSEED_PIN, INPUT_PULLUP);
diff --git a/hal/architecture/MyHwESP8266.cpp b/hal/architecture/MyHwESP8266.cpp
index a11e1da..fcce169 100644
--- a/hal/architecture/MyHwESP8266.cpp
+++ b/hal/architecture/MyHwESP8266.cpp
@@ -89,14 +89,14 @@ ssize_t hwGetentropy(void *__buffer, size_t __length)
 	return __length;
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)ms;
 	return MY_SLEEP_NOT_POSSIBLE;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt;
@@ -106,7 +106,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt1;
diff --git a/hal/architecture/MyHwLinuxGeneric.cpp b/hal/architecture/MyHwLinuxGeneric.cpp
index 8c6649d..6256e66 100644
--- a/hal/architecture/MyHwLinuxGeneric.cpp
+++ b/hal/architecture/MyHwLinuxGeneric.cpp
@@ -68,7 +68,7 @@ void hwWriteConfig(int addr, uint8_t value)
 
 void hwRandomNumberInit()
 {
-	unsigned long seed=0;
+	uint32_t seed=0;
 
 	if (randomFp != NULL) {
 		fclose(randomFp);
@@ -87,7 +87,7 @@ ssize_t hwGetentropy(void *__buffer, size_t __length)
 	return(fread(__buffer, 1, __length, randomFp));
 }
 
-unsigned long hwMillis()
+uint32_t hwMillis()
 {
 	return millis();
 }
@@ -100,7 +100,7 @@ bool hwUniqueID(unique_id_t *uniqueID)
 }
 
 // Not supported!
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	(void)ms;
 
@@ -108,7 +108,7 @@ int8_t hwSleep(unsigned long ms)
 }
 
 // Not supported!
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	(void)interrupt;
 	(void)mode;
@@ -119,7 +119,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
 
 // Not supported!
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	(void)interrupt1;
 	(void)mode1;
diff --git a/hal/architecture/MyHwLinuxGeneric.h b/hal/architecture/MyHwLinuxGeneric.h
index b02e216..3c57b98 100644
--- a/hal/architecture/MyHwLinuxGeneric.h
+++ b/hal/architecture/MyHwLinuxGeneric.h
@@ -1,4 +1,4 @@
-/*
+/*
  * The MySensors Arduino library handles the wireless radio link and protocol
  * between your home built sensors/actuators and HA controller of choice.
  * The sensors forms a self healing radio network with optional repeaters. Each
@@ -59,7 +59,7 @@ inline void hwWriteConfig(int addr, uint8_t value);
 inline void hwRandomNumberInit();
 ssize_t hwGetentropy(void *__buffer, size_t __length);
 #define MY_HW_HAS_GETENTROPY
-inline unsigned long hwMillis();
+inline uint32_t hwMillis();
 
 #ifdef MY_RF24_IRQ_PIN
 static pthread_mutex_t hw_mutex = PTHREAD_MUTEX_INITIALIZER;
diff --git a/hal/architecture/MyHwNRF5.cpp b/hal/architecture/MyHwNRF5.cpp
index 00afe48..024c4eb 100644
--- a/hal/architecture/MyHwNRF5.cpp
+++ b/hal/architecture/MyHwNRF5.cpp
@@ -210,7 +210,7 @@ void hwReboot()
 static volatile bool nrf5_rtc_event_triggered;
 static volatile bool nrf5_pwr_hfclk;
 
-void hwSleepPrepare(unsigned long ms)
+void hwSleepPrepare(uint32_t ms)
 {
 	// Enable low power sleep mode
 	NRF_POWER->TASKS_LOWPWR = 1;
@@ -271,7 +271,7 @@ void hwSleepPrepare(unsigned long ms)
 	}
 }
 
-void hwSleepEnd(unsigned long ms)
+void hwSleepEnd(uint32_t ms)
 {
 	// Start HFCLK
 	if (nrf5_pwr_hfclk) {
@@ -319,7 +319,7 @@ inline void hwSleep()
 	__WFE();
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	hwSleepPrepare(ms);
 	while (nrf5_rtc_event_triggered == false) {
@@ -329,13 +329,13 @@ int8_t hwSleep(unsigned long ms)
 	return MY_WAKE_UP_BY_TIMER;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	return hwSleep(interrupt, mode, INVALID_INTERRUPT_NUM, 0u, ms);
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2,
-               uint8_t mode2, unsigned long ms)
+               uint8_t mode2, uint32_t ms)
 {
 	// Disable interrupts until going to sleep, otherwise interrupts occurring
 	// between attachInterrupt()
diff --git a/hal/architecture/MyHwSAMD.cpp b/hal/architecture/MyHwSAMD.cpp
index c83eca7..2533da6 100644
--- a/hal/architecture/MyHwSAMD.cpp
+++ b/hal/architecture/MyHwSAMD.cpp
@@ -95,14 +95,14 @@ void hwReboot(void)
 	while (true);
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)ms;
 	return MY_SLEEP_NOT_POSSIBLE;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt;
@@ -112,7 +112,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt1;
diff --git a/hal/architecture/MyHwSTM32F1.cpp b/hal/architecture/MyHwSTM32F1.cpp
index f213ba0..ccd7013 100644
--- a/hal/architecture/MyHwSTM32F1.cpp
+++ b/hal/architecture/MyHwSTM32F1.cpp
@@ -89,14 +89,14 @@ void hwWriteConfig(const int addr, uint8_t value)
 	hwWriteConfigBlock(&value, reinterpret_cast<void*>(addr), 1);
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)ms;
 	return MY_SLEEP_NOT_POSSIBLE;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt;
@@ -106,7 +106,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt1;
diff --git a/hal/architecture/MyHwTeensy3.cpp b/hal/architecture/MyHwTeensy3.cpp
index c9e7702..6355ce9 100644
--- a/hal/architecture/MyHwTeensy3.cpp
+++ b/hal/architecture/MyHwTeensy3.cpp
@@ -60,14 +60,14 @@ void hwReboot(void)
 	while (true);
 }
 
-int8_t hwSleep(unsigned long ms)
+int8_t hwSleep(uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)ms;
 	return MY_SLEEP_NOT_POSSIBLE;
 }
 
-int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt;
@@ -77,7 +77,7 @@ int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms)
 }
 
 int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2,
-               unsigned long ms)
+               uint32_t ms)
 {
 	// TODO: Not supported!
 	(void)interrupt1;