diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index 218291b4cf..86d4bb0337 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -39,19 +39,7 @@
 #include "types.h"
 #include "fastio.h"
 #include "utility.h"
-
-#ifdef USBCON
-  #include "HardwareSerial.h"
-  #if ENABLED(BLUETOOTH)
-    #define MYSERIAL bluetoothSerial
-  #else
-    #define MYSERIAL Serial
-  #endif // BLUETOOTH
-#else
-  #include "MarlinSerial.h"
-  #define MYSERIAL customizedSerial
-#endif
-
+#include "serial.h"
 #include "WString.h"
 
 #if ENABLED(PRINTCOUNTER)
@@ -60,54 +48,6 @@
   #include "stopwatch.h"
 #endif
 
-extern const char echomagic[] PROGMEM;
-extern const char errormagic[] PROGMEM;
-
-#define SERIAL_CHAR(x) (MYSERIAL.write(x))
-#define SERIAL_EOL SERIAL_CHAR('\n')
-
-#define SERIAL_PROTOCOLCHAR(x)              SERIAL_CHAR(x)
-#define SERIAL_PROTOCOL(x)                  (MYSERIAL.print(x))
-#define SERIAL_PROTOCOL_F(x,y)              (MYSERIAL.print(x,y))
-#define SERIAL_PROTOCOLPGM(x)               (serialprintPGM(PSTR(x)))
-#define SERIAL_PROTOCOLLN(x)                do{ MYSERIAL.print(x); SERIAL_EOL; }while(0)
-#define SERIAL_PROTOCOLLNPGM(x)             (serialprintPGM(PSTR(x "\n")))
-#define SERIAL_PROTOCOLPAIR(name, value)    (serial_echopair_P(PSTR(name),(value)))
-#define SERIAL_PROTOCOLLNPAIR(name, value)  do{ SERIAL_PROTOCOLPAIR(name, value); SERIAL_EOL; }while(0)
-
-#define SERIAL_ECHO_START             (serialprintPGM(echomagic))
-#define SERIAL_ECHO(x)                 SERIAL_PROTOCOL(x)
-#define SERIAL_ECHOPGM(x)              SERIAL_PROTOCOLPGM(x)
-#define SERIAL_ECHOLN(x)               SERIAL_PROTOCOLLN(x)
-#define SERIAL_ECHOLNPGM(x)            SERIAL_PROTOCOLLNPGM(x)
-#define SERIAL_ECHOPAIR(name,value)    SERIAL_PROTOCOLPAIR(name, value)
-#define SERIAL_ECHOLNPAIR(name, value) SERIAL_PROTOCOLLNPAIR(name, value)
-#define SERIAL_ECHO_F(x,y)             SERIAL_PROTOCOL_F(x,y)
-
-#define SERIAL_ERROR_START            (serialprintPGM(errormagic))
-#define SERIAL_ERROR(x)                SERIAL_PROTOCOL(x)
-#define SERIAL_ERRORPGM(x)             SERIAL_PROTOCOLPGM(x)
-#define SERIAL_ERRORLN(x)              SERIAL_PROTOCOLLN(x)
-#define SERIAL_ERRORLNPGM(x)           SERIAL_PROTOCOLLNPGM(x)
-
-void serial_echopair_P(const char* s_P, const char *v);
-void serial_echopair_P(const char* s_P, char v);
-void serial_echopair_P(const char* s_P, int v);
-void serial_echopair_P(const char* s_P, long v);
-void serial_echopair_P(const char* s_P, float v);
-void serial_echopair_P(const char* s_P, double v);
-void serial_echopair_P(const char* s_P, unsigned int v);
-void serial_echopair_P(const char* s_P, unsigned long v);
-FORCE_INLINE void serial_echopair_P(const char* s_P, uint8_t v) { serial_echopair_P(s_P, (int)v); }
-FORCE_INLINE void serial_echopair_P(const char* s_P, uint16_t v) { serial_echopair_P(s_P, (int)v); }
-FORCE_INLINE void serial_echopair_P(const char* s_P, bool v) { serial_echopair_P(s_P, (int)v); }
-FORCE_INLINE void serial_echopair_P(const char* s_P, void *v) { serial_echopair_P(s_P, (unsigned long)v); }
-
-// Things to write to serial from Program memory. Saves 400 to 2k of RAM.
-FORCE_INLINE void serialprintPGM(const char* str) {
-  while (char ch = pgm_read_byte(str++)) MYSERIAL.write(ch);
-}
-
 void idle(
   #if ENABLED(FILAMENT_CHANGE_FEATURE)
     bool no_stepper_sleep = false  // pass true to keep steppers from disabling on timeout
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 27ef4f6105..79771ae06b 100755
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -447,8 +447,6 @@ volatile bool wait_for_heatup = true;
   volatile bool wait_for_user = false;
 #endif
 
-const char errormagic[] PROGMEM = "Error:";
-const char echomagic[] PROGMEM = "echo:";
 const char axis_codes[XYZE] = {'X', 'Y', 'Z', 'E'};
 
 // Number of characters read in the current line of serial input
@@ -696,14 +694,6 @@ void set_current_from_steppers_for_axis(const AxisEnum axis);
   void plan_cubic_move(const float offset[4]);
 #endif
 
-void serial_echopair_P(const char* s_P, const char *v)   { serialprintPGM(s_P); SERIAL_ECHO(v); }
-void serial_echopair_P(const char* s_P, char v)          { serialprintPGM(s_P); SERIAL_CHAR(v); }
-void serial_echopair_P(const char* s_P, int v)           { serialprintPGM(s_P); SERIAL_ECHO(v); }
-void serial_echopair_P(const char* s_P, long v)          { serialprintPGM(s_P); SERIAL_ECHO(v); }
-void serial_echopair_P(const char* s_P, float v)         { serialprintPGM(s_P); SERIAL_ECHO(v); }
-void serial_echopair_P(const char* s_P, double v)        { serialprintPGM(s_P); SERIAL_ECHO(v); }
-void serial_echopair_P(const char* s_P, unsigned long v) { serialprintPGM(s_P); SERIAL_ECHO(v); }
-
 void tool_change(const uint8_t tmp_extruder, const float fr_mm_s=0.0, bool no_move=false);
 static void report_current_position();
 
diff --git a/Marlin/serial.cpp b/Marlin/serial.cpp
new file mode 100644
index 0000000000..9b5ae139e4
--- /dev/null
+++ b/Marlin/serial.cpp
@@ -0,0 +1,34 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "serial.h"
+
+const char errormagic[] PROGMEM = "Error:";
+const char echomagic[] PROGMEM = "echo:";
+
+void serial_echopair_P(const char* s_P, const char *v)   { serialprintPGM(s_P); SERIAL_ECHO(v); }
+void serial_echopair_P(const char* s_P, char v)          { serialprintPGM(s_P); SERIAL_CHAR(v); }
+void serial_echopair_P(const char* s_P, int v)           { serialprintPGM(s_P); SERIAL_ECHO(v); }
+void serial_echopair_P(const char* s_P, long v)          { serialprintPGM(s_P); SERIAL_ECHO(v); }
+void serial_echopair_P(const char* s_P, float v)         { serialprintPGM(s_P); SERIAL_ECHO(v); }
+void serial_echopair_P(const char* s_P, double v)        { serialprintPGM(s_P); SERIAL_ECHO(v); }
+void serial_echopair_P(const char* s_P, unsigned long v) { serialprintPGM(s_P); SERIAL_ECHO(v); }
diff --git a/Marlin/serial.h b/Marlin/serial.h
new file mode 100644
index 0000000000..864a9d8f66
--- /dev/null
+++ b/Marlin/serial.h
@@ -0,0 +1,88 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef __SERIAL_H__
+#define __SERIAL_H__
+
+#ifdef USBCON
+  #include "HardwareSerial.h"
+  #if ENABLED(BLUETOOTH)
+    #define MYSERIAL bluetoothSerial
+  #else
+    #define MYSERIAL Serial
+  #endif // BLUETOOTH
+#else
+  #include "MarlinSerial.h"
+  #define MYSERIAL customizedSerial
+#endif
+
+extern const char echomagic[] PROGMEM;
+extern const char errormagic[] PROGMEM;
+
+#define SERIAL_CHAR(x) (MYSERIAL.write(x))
+#define SERIAL_EOL SERIAL_CHAR('\n')
+
+#define SERIAL_PROTOCOLCHAR(x)              SERIAL_CHAR(x)
+#define SERIAL_PROTOCOL(x)                  (MYSERIAL.print(x))
+#define SERIAL_PROTOCOL_F(x,y)              (MYSERIAL.print(x,y))
+#define SERIAL_PROTOCOLPGM(x)               (serialprintPGM(PSTR(x)))
+#define SERIAL_PROTOCOLLN(x)                do{ MYSERIAL.print(x); SERIAL_EOL; }while(0)
+#define SERIAL_PROTOCOLLNPGM(x)             (serialprintPGM(PSTR(x "\n")))
+#define SERIAL_PROTOCOLPAIR(name, value)    (serial_echopair_P(PSTR(name),(value)))
+#define SERIAL_PROTOCOLLNPAIR(name, value)  do{ SERIAL_PROTOCOLPAIR(name, value); SERIAL_EOL; }while(0)
+
+#define SERIAL_ECHO_START             (serialprintPGM(echomagic))
+#define SERIAL_ECHO(x)                 SERIAL_PROTOCOL(x)
+#define SERIAL_ECHOPGM(x)              SERIAL_PROTOCOLPGM(x)
+#define SERIAL_ECHOLN(x)               SERIAL_PROTOCOLLN(x)
+#define SERIAL_ECHOLNPGM(x)            SERIAL_PROTOCOLLNPGM(x)
+#define SERIAL_ECHOPAIR(name,value)    SERIAL_PROTOCOLPAIR(name, value)
+#define SERIAL_ECHOLNPAIR(name, value) SERIAL_PROTOCOLLNPAIR(name, value)
+#define SERIAL_ECHO_F(x,y)             SERIAL_PROTOCOL_F(x,y)
+
+#define SERIAL_ERROR_START            (serialprintPGM(errormagic))
+#define SERIAL_ERROR(x)                SERIAL_PROTOCOL(x)
+#define SERIAL_ERRORPGM(x)             SERIAL_PROTOCOLPGM(x)
+#define SERIAL_ERRORLN(x)              SERIAL_PROTOCOLLN(x)
+#define SERIAL_ERRORLNPGM(x)           SERIAL_PROTOCOLLNPGM(x)
+
+void serial_echopair_P(const char* s_P, const char *v);
+void serial_echopair_P(const char* s_P, char v);
+void serial_echopair_P(const char* s_P, int v);
+void serial_echopair_P(const char* s_P, long v);
+void serial_echopair_P(const char* s_P, float v);
+void serial_echopair_P(const char* s_P, double v);
+void serial_echopair_P(const char* s_P, unsigned int v);
+void serial_echopair_P(const char* s_P, unsigned long v);
+FORCE_INLINE void serial_echopair_P(const char* s_P, uint8_t v) { serial_echopair_P(s_P, (int)v); }
+FORCE_INLINE void serial_echopair_P(const char* s_P, uint16_t v) { serial_echopair_P(s_P, (int)v); }
+FORCE_INLINE void serial_echopair_P(const char* s_P, bool v) { serial_echopair_P(s_P, (int)v); }
+FORCE_INLINE void serial_echopair_P(const char* s_P, void *v) { serial_echopair_P(s_P, (unsigned long)v); }
+
+//
+// Functions for serial printing from PROGMEM. (Saves loads of SRAM.)
+//
+FORCE_INLINE void serialprintPGM(const char* str) {
+  while (char ch = pgm_read_byte(str++)) MYSERIAL.write(ch);
+}
+
+#endif // __SERIAL_H__