Make debug prints portable (#929)

hal/architecture/MyHwSTM32F1.cpp

@@ -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
@@ -173,8 +173,8 @@ void hwDebugPrint(const char *fmt, ...)
 	char fmtBuffer[MY_SERIAL_OUTPUT_SIZE];
 #ifdef MY_GATEWAY_SERIAL
 	// prepend debug message to be handled correctly by controller (C_INTERNAL, I_LOG_MESSAGE)
-	snprintf_P(fmtBuffer, sizeof(fmtBuffer), PSTR("0;255;%d;0;%d;%lu "), C_INTERNAL, I_LOG_MESSAGE,
-	           hwMillis());
+	snprintf_P(fmtBuffer, sizeof(fmtBuffer), PSTR("0;255;%" PRIu8 ";0;%" PRIu8 ";%" PRIu32 " "),
+	           C_INTERNAL, I_LOG_MESSAGE, hwMillis());
 	MY_SERIALDEVICE.print(fmtBuffer);
 #else
 	// prepend timestamp
@@ -194,5 +194,7 @@ void hwDebugPrint(const char *fmt, ...)
 	// Disable flush since current STM32duino implementation performs a reset
 	// instead of an actual flush
 	//MY_SERIALDEVICE.flush();
+#else
+	(void)fmt;
 #endif
 }