GPS not responding to $PSRF1xx commands

Projects Networking, Protocols, and Devices
1

Hi,

I use a Globalsat EM-408 GPS with my Mega 1280.
I have no problems about reading NMEA data and/or parsing them with TinyGPS library.
Nonetheless I would change some settings in setup (baud, sampling freq...). Here's a piece of my code to change the baud.

Serial1.begin(9600) ;
Serial1.print('$PSRF100,1,9600,8,1,0*38<CR><LF>') ; //

but the GPS continues to transmit at 4800.
I read this old topic (it's read only...) http://arduino.cc/forum/index.php/topic,10812.0.html but the solution is not posted.
Can anybody help me?

Thank you so much!

2

Sorry,
I'm a newbie of the forum and I didn't see that my topic was locked..now it's OK!

Anyhow, with the important collaboration of wayneft, I found the solution.

Serial1.begin(BAUD1) ;
delay(300) ;
Serial1.print("$PSRF103,0,0,0,0*25\r\n") ; // GGA off
delay(300) ;

This is an example code that sends to the GPS the NMEA message to turn the GGA option off.
Neglecting the mistakes I did before with single/double quotes, the most important parts are the delay().
Without them the code doesn't work: I think that it is due to the fact that they give the time to the GPS to receive the whole message and change status.

NOTE ABOUT THE CHECKSUM:
I expected that disabling the checkSum (the zero in "025"), the second number (the 25 of "025") should be useless..that's not true, but I did not find the reason.

See you!