diff --git a/core/MyHwATMega328.cpp b/core/MyHwATMega328.cpp
index 349e775..100d7ed 100644
--- a/core/MyHwATMega328.cpp
+++ b/core/MyHwATMega328.cpp
@@ -198,22 +198,21 @@ uint16_t hwFreeMem() {
 
 #ifdef MY_DEBUG
 void hwDebugPrint(const char *fmt, ... ) {
-	char fmtBuffer[300];
+	char fmtBuffer[MY_DEBUG_BUFFER_SIZE];
 	#ifdef MY_GATEWAY_FEATURE
 		// prepend debug message to be handled correctly by controller (C_INTERNAL, I_LOG_MESSAGE)
-		snprintf_P(fmtBuffer, 299, PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
+		snprintf_P(fmtBuffer, sizeof(fmtBuffer), PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
 		MY_SERIALDEVICE.print(fmtBuffer);
 	#endif
 	va_list args;
 	va_start (args, fmt );
-	va_end (args);
 	#ifdef MY_GATEWAY_FEATURE
 		// Truncate message if this is gateway node
 		vsnprintf_P(fmtBuffer, MY_GATEWAY_MAX_SEND_LENGTH, fmt, args);
 		fmtBuffer[MY_GATEWAY_MAX_SEND_LENGTH-1] = '\n';
 		fmtBuffer[MY_GATEWAY_MAX_SEND_LENGTH] = '\0';
 	#else
-		vsnprintf_P(fmtBuffer, 299, fmt, args);
+		vsnprintf_P(fmtBuffer, sizeof(fmtBuffer), fmt, args);
 	#endif
 	va_end (args);
 	MY_SERIALDEVICE.print(fmtBuffer);
diff --git a/core/MyHwATMega328.h b/core/MyHwATMega328.h
index 157ecb1..8d6c102 100644
--- a/core/MyHwATMega328.h
+++ b/core/MyHwATMega328.h
@@ -35,6 +35,8 @@
 #endif
 
 #define MY_SERIALDEVICE Serial
+#define MY_DEBUG_BUFFER_SIZE 300
+
 #if defined __AVR_ATmega328P__
 #ifndef sleep_bod_disable
 #define sleep_bod_disable() 										\
diff --git a/core/MyHwESP8266.cpp b/core/MyHwESP8266.cpp
index 1e50156..3c10105 100644
--- a/core/MyHwESP8266.cpp
+++ b/core/MyHwESP8266.cpp
@@ -132,22 +132,21 @@ uint16_t hwFreeMem() {
 
 #ifdef MY_DEBUG
 void hwDebugPrint(const char *fmt, ... ) {
-	char fmtBuffer[300];
+	char fmtBuffer[MY_DEBUG_BUFFER_SIZE];
 	#ifdef MY_GATEWAY_FEATURE
 		// prepend debug message to be handled correctly by controller (C_INTERNAL, I_LOG_MESSAGE)
-		snprintf_P(fmtBuffer, 299, PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
+		snprintf_P(fmtBuffer, sizeof(fmtBuffer), PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
 		MY_SERIALDEVICE.print(fmtBuffer);
 	#endif
 	va_list args;
 	va_start (args, fmt );
-	va_end (args);
 	#ifdef MY_GATEWAY_FEATURE
 		// Truncate message if this is gateway node
 		vsnprintf_P(fmtBuffer, MY_GATEWAY_MAX_SEND_LENGTH, fmt, args);
 		fmtBuffer[MY_GATEWAY_MAX_SEND_LENGTH-1] = '\n';
 		fmtBuffer[MY_GATEWAY_MAX_SEND_LENGTH] = '\0';
 	#else
-		vsnprintf_P(fmtBuffer, 299, fmt, args);
+		vsnprintf_P(fmtBuffer, sizeof(fmtBuffer), fmt, args);
 	#endif
 	va_end (args);
 	MY_SERIALDEVICE.print(fmtBuffer);
diff --git a/core/MyHwESP8266.h b/core/MyHwESP8266.h
index 1495e69..ffbcb69 100644
--- a/core/MyHwESP8266.h
+++ b/core/MyHwESP8266.h
@@ -26,6 +26,8 @@
 #endif
 
 #define MY_SERIALDEVICE Serial
+#define MY_DEBUG_BUFFER_SIZE 300
+
 #define min(a,b) ((a)<(b)?(a):(b))
 #define max(a,b) ((a)>(b)?(a):(b))
 
diff --git a/core/MyHwSAMD.cpp b/core/MyHwSAMD.cpp
index 264da9c..2d85501 100644
--- a/core/MyHwSAMD.cpp
+++ b/core/MyHwSAMD.cpp
@@ -156,22 +156,21 @@ uint16_t hwFreeMem() {
 #ifdef MY_DEBUG
 void hwDebugPrint(const char *fmt, ... ) {
   if (MY_SERIALDEVICE) {
-	char fmtBuffer[300];
+	char fmtBuffer[MY_DEBUG_BUFFER_SIZE];
 	#ifdef MY_GATEWAY_FEATURE
 		// prepend debug message to be handled correctly by controller (C_INTERNAL, I_LOG_MESSAGE)
-		snprintf(fmtBuffer, 299, PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
+		snprintf(fmtBuffer, sizeof(fmtBuffer), PSTR("0;255;%d;0;%d;"), C_INTERNAL, I_LOG_MESSAGE);
 		MY_SERIALDEVICE.print(fmtBuffer);
 	#endif
 	va_list args;
 	va_start (args, fmt );
-	va_end (args);
 	#ifdef MY_GATEWAY_FEATURE
 		// Truncate message if this is gateway node
 		vsnprintf(fmtBuffer, 60, fmt, args);
 		fmtBuffer[59] = '\n';
 		fmtBuffer[60] = '\0';
 	#else
-		vsnprintf(fmtBuffer, 299, fmt, args);
+		vsnprintf(fmtBuffer, sizeof(fmtBuffer), fmt, args);
 	#endif
 	va_end (args);
 	MY_SERIALDEVICE.print(fmtBuffer);
diff --git a/core/MyHwSAMD.h b/core/MyHwSAMD.h
index dcb783c..dce2dba 100644
--- a/core/MyHwSAMD.h
+++ b/core/MyHwSAMD.h
@@ -50,6 +50,7 @@ void hwWriteConfig(int adr, uint8_t value);
 uint8_t hwReadConfig(int adr);
 
 #define MY_SERIALDEVICE SerialUSB
+#define MY_DEBUG_BUFFER_SIZE 300
 
 
 /*