Added software serial platform macro

src/Module.cpp

@@ -7,8 +7,8 @@ Module::Module(int rx, int tx, HardwareSerial* useSer) {
   _int0 = -1;
   _int1 = -1;
 
-#if defined(ESP32) || defined(SAMD_SERIES) || defined (ARDUINO_ARCH_STM32)
-    ModuleSerial = useSer;
+#if SOFTWARE_SERIAL_UNSUPPORTED
+  ModuleSerial = useSer;
 #else
   ModuleSerial = new SoftwareSerial(_rx, _tx);
 #endif
@@ -33,7 +33,7 @@ Module::Module(int cs, int int0, int int1, int rx, int tx, SPIClass& spi, SPISet
   _spi = &spi;
   _spiSettings = spiSettings;
 
-#if defined(ESP32) || defined(SAMD_SERIES) || defined (ARDUINO_ARCH_STM32)
+#if SOFTWARE_SERIAL_UNSUPPORTED
   ModuleSerial = useSer;
 #else
   ModuleSerial = new SoftwareSerial(_rx, _tx);

src/TypeDef.h

@@ -7,6 +7,9 @@
   #error "Unsupported Arduino version (< 1.0.0)"
 #endif
 
+// the following platforms do not support SoftwareSerial library
+#define SOFTWARE_SERIAL_UNSUPPORTED (defined(ESP32) || defined(SAMD_SERIES) || defined (ARDUINO_ARCH_STM32))
+
 #define RADIOLIB_DEBUG_PORT  Serial
 
 //#define RADIOLIB_DEBUG