Update example configurations

Marlin/src/config/default/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/AlephObjects/TAZ4/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/AliExpress/CL-260/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Anet/A6/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Anet/A8/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Azteeg/X5GT/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/BQ/Hephestos/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/BQ/Hephestos_2/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/BQ/WITBOX/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Cartesio/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Creality/CR-10/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Felix/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Felix/DUAL/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Geeetech/GT2560/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Geeetech/I3_Pro_X-GT2560/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Infitary/i3-M508/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Malyan/M150/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Micromake/C1/basic/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Micromake/C1/enhanced/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Mks/Sbase/Configuration.h

  *
  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-#define SERIAL_PORT -1
+#define SERIAL_PORT 0
+
+/**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
 
 /**
  * This setting determines the communication speed of the printer.

Marlin/src/config/examples/RepRapWorld/Megatronics/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/RigidBot/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/SCARA/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/STM32F10/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Sanguinololu/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/TinyBoy2/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Velleman/K8200/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Velleman/K8400/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/Velleman/K8400/Dual-head/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/adafruit/ST7565/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/generic/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/kossel_mini/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/kossel_pro/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/delta/kossel_xl/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/makibox/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/tvrrug/Round2/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if

Marlin/src/config/examples/wt150/Configuration.h

 #define SERIAL_PORT 0
 
 /**
+  * Select a secondary serial port on the board to use for communication with the host.
+  * This allows the connection of wireless adapters (for instance) to non-default port pins.
+  * Serial port -1 is the USB emulated serial port, if avaialble.
+  *
+  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
+  */
+#define SERIAL_PORT_2 -1
+
+/**
  * This setting determines the communication speed of the printer.
  *
  * 250000 works in most cases, but you might try a lower speed if