diff --git a/DCC.cpp b/DCC.cpp
index 71a09c7..f8ca7b1 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -62,11 +62,7 @@ byte DCC::globalSpeedsteps=128;
 
 void DCC::begin(const FSH * motorShieldName) {
   shieldName=(FSH *)motorShieldName;
-#if defined(ARDUINO_ARCH_SAMD)
-  StringFormatter::send(SerialUSB,F("<iDCC-EX V-%S / %S / %S G-%S>\n"), F(VERSION), F(ARDUINO_TYPE), shieldName, F(GITHUB_SHA));
-#else
-  StringFormatter::send(Serial,F("<iDCC-EX V-%S / %S / %S G-%S>\n"), F(VERSION), F(ARDUINO_TYPE), shieldName, F(GITHUB_SHA));
-#endif
+  StringFormatter::send(&USB_SERIAL,F("<iDCC-EX V-%S / %S / %S G-%S>\n"), F(VERSION), F(ARDUINO_TYPE), shieldName, F(GITHUB_SHA));
 #ifndef DISABLE_EEPROM
   // Load stuff from EEprom
   (void)EEPROM; // tell compiler not to warn this is unused
diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index d264281..d1630c2 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -183,7 +183,7 @@ void DCCEXParser::parse(const FSH * cmd) {
       int size=strlen_P((char *)cmd)+1; 
       char buffer[size];
       strcpy_P(buffer,(char *)cmd);
-      parse(&Serial,(byte *)buffer,NULL);
+      parse(&USB_SERIAL,(byte *)buffer,NULL);
 }
 
 // See documentation on DCC class for info on this section
diff --git a/SerialManager.cpp b/SerialManager.cpp
index 93dc1bb..4b6bcf5 100644
--- a/SerialManager.cpp
+++ b/SerialManager.cpp
@@ -22,6 +22,7 @@
 
 #include "SerialManager.h"
 #include "DCCEXParser.h"
+#include "StringFormatter.h"
 
 SerialManager * SerialManager::first=NULL;
 
@@ -34,14 +35,10 @@ SerialManager::SerialManager(Stream * myserial) {
 } 
 
 void SerialManager::init() {
-#if defined(ARDUINO_ARCH_SAMD)
-  SerialUSB.begin(115200);
-  new SerialManager(&SerialUSB);
-#else
-  Serial.begin(115200);
-  while (!Serial && millis() < 5000); // wait max 5s for Serial to start
-  new SerialManager(&Serial);
-#endif
+  USB_SERIAL.begin(115200);
+  while (!USB_SERIAL && millis() < 5000); // wait max 5s for Serial to start
+  new SerialManager(&USB_SERIAL);
+  
 #ifdef SERIAL3_COMMANDS
   Serial3.begin(115200);
   new SerialManager(&Serial3);
diff --git a/StringFormatter.cpp b/StringFormatter.cpp
index ff5a96a..ccb6ef3 100644
--- a/StringFormatter.cpp
+++ b/StringFormatter.cpp
@@ -18,15 +18,6 @@
  */
 #include "StringFormatter.h"
 #include <stdarg.h>
-
-#if defined(ARDUINO_ARCH_SAMD)
-   // Some processors use a gcc compiler that renames va_list!!!
-  #include <cstdarg>
-  Print * StringFormatter::diagSerial= &SerialUSB; 
-#else
-  Print * StringFormatter::diagSerial=&Serial;
-#endif
-
 #include "LCDDisplay.h"
 
 bool Diag::ACK=false;
@@ -38,22 +29,21 @@ bool Diag::LCN=false;
 
  
 void StringFormatter::diag( const FSH* input...) {
-  if (!diagSerial) return; 
-  diagSerial->print(F("<* "));   
+ USB_SERIAL.print(F("<* "));   
   va_list args;
   va_start(args, input);
-  send2(diagSerial,input,args);
-  diagSerial->print(F(" *>\n"));
+  send2(&USB_SERIAL,input,args);
+  USB_SERIAL.print(F(" *>\n"));
 }
 
 void StringFormatter::lcd(byte row, const FSH* input...) {
   va_list args;
 
   // Issue the LCD as a diag first
-  send(diagSerial,F("<* LCD%d:"),row);
+  send(&USB_SERIAL,F("<* LCD%d:"),row);
   va_start(args, input);
-  send2(diagSerial,input,args);
-  send(diagSerial,F(" *>\n"));
+  send2(&USB_SERIAL,input,args);
+  send(&USB_SERIAL,F(" *>\n"));
   
   if (!LCDDisplay::lcdDisplay) return;
   LCDDisplay::lcdDisplay->setRow(row);    
@@ -164,7 +154,7 @@ void StringFormatter::printEscapes(Print * stream, const FSH * input) {
 }
 
 void StringFormatter::printEscape( char c) {
-  printEscape(diagSerial,c);
+  printEscape(&USB_SERIAL,c);
 }
 
 void StringFormatter::printEscape(Print * stream, char c) {
diff --git a/StringFormatter.h b/StringFormatter.h
index 1e225b5..4787715 100644
--- a/StringFormatter.h
+++ b/StringFormatter.h
@@ -21,12 +21,6 @@
 #include <Arduino.h>
 #include "FSH.h"
 #include "RingStream.h"
- 
-#if defined(ARDUINO_ARCH_SAMD)
-   // Some processors use a gcc compiler that renames va_list!!!
-  #include <cstdarg>  
-#endif
-
 #include "LCDDisplay.h"
 class Diag {
   public:
@@ -50,7 +44,6 @@ class StringFormatter
     static void printEscape(Print * serial, char c);
 
     // DIAG support
-    static Print * diagSerial;
     static void diag( const FSH* input...);
     static void lcd(byte row, const FSH* input...);
     static void printEscapes(char * input);
diff --git a/WifiInterface.cpp b/WifiInterface.cpp
index b7b059e..5f3b8e6 100644
--- a/WifiInterface.cpp
+++ b/WifiInterface.cpp
@@ -381,7 +381,7 @@ bool WifiInterface::checkForOK( const unsigned int timeout, const FSH * waitfor,
       int ch = wifiStream->read();
       if (echo) {
         if (escapeEcho) StringFormatter::printEscape( ch); /// THIS IS A DIAG IN DISGUISE
-        else StringFormatter::diagSerial->print((char)ch); 
+        else USB_SERIAL.print((char)ch); 
       }
       if (ch != GETFLASH(locator)) locator = (char *)waitfor;
       if (ch == GETFLASH(locator)) {
diff --git a/defines.h b/defines.h
index a51f41f..d2aba22 100644
--- a/defines.h
+++ b/defines.h
@@ -41,6 +41,7 @@
 // figure out if we have enough memory for advanced features
 // so define HAS_ENOUGH_MEMORY until proved otherwise.
 #define HAS_ENOUGH_MEMORY
+#define USB_SERIAL Serial
 
 #if defined(ARDUINO_AVR_UNO)
 #define ARDUINO_TYPE "UNO"
@@ -71,6 +72,8 @@
 #define ARDUINO_TYPE "ESP32"
 #elif defined(ARDUINO_ARCH_SAMD)
 #define ARDUINO_TYPE "SAMD21"
+#undef USB_SERIAL
+#define USB_SERIAL SerialUSB
 // SAMD support for I2C is awaiting development 
 #ifndef DISABLE_EEPROM
   #define DISABLE_EEPROM