CONFIG.txt

Configuration and command set
+++++++++++++++++++++++++++++

There are a variety of commands that can be sent to the Mega over a serial terminal. 
The easiest is to install the Arduino IDE (available from the arduino site) and use the Serial terminal in that program.

I am assuming your mega is probably connected to your computer with a USB cable at this point. Open the serial 
terminal program on the Mega's port (COM4 or similar in Windows, probably /dev/ttyUSB? in linux). The default baud rate
etc is 38400, 8, N, 1.

You should see a few boot messages, then recurring $IIMVW... NMEA messages, and !!VER:1.9,.. messages.

The default configuration is:
	GPS Model= GPS_EM_406A
	config.serial0 Baud=38400
	serial1 Baud=38400
	serial2 Baud=9600
	serial3 Baud=9600
	seaTalk on serial2 = OFF;
	
You can now send commands to the Mega to alter the configuration:

A command is #, 3 letters, : , and the value to be set. eg '#GPS=1'. Multiple commands 
are separated with a comma, eg #GPS=1,#SB1=9600,

The #CFG command with no parameters will cause the current config to be printed to the serial port.

The default GPS model is EM406A, at 38400 on Serial1
Options are #GPS=0 for generic GPS 
Options are #GPS=1 for EM406A GPS  - also recommend switching to 38400bps
Options are #GPS=2 for MTEK_3329 GPS  - also recommend switching to 38400bps

Changing baud rates:

Possible baud rates are 4800, 9600, 19200, 38400, 57600
eg for baud rate 38400 #SB0=38400
Main serial0 (shared with USB) #SB0 - (WARNING: if you change this and reboot, you will need to reconnect at the new speed.)
Serial1 - usually GPS #SB1
Serial2 - optionally used for Seatalk #SB2
Serial3 #SB3

Use Serial2 for SEATALK, also sets baud at 4800: #STK=1
Dont use Serial2 for SEATALK:  #STK=0  (set baud with #SB2 above)

Examples:
Print out current config:

#CFG  hit [ENTER]

Set an existing generic gps on serial1 at 4800bps

#GPS=0,#SB1=4800, hit [ENTER]

To make serial2 listen for Seatalk at 4800bps

#STK=1, Hit [Enter]

To listen for AIS on serial 3 at 38400bps (default for AIS)

#SB3=38400, hit [Enter]

The changes are saved immediately, but wont take effect till the next reboot.