GPS not responding to $PSRF1xx commands

Hi,

I have a USGlobalStat EM-402 GPS. It uses the SiRFStarII chipset (http://www.sparkfun.com/commerce/product_info.php?products_id=576). It's spewing out so much data that it's overwhelming my arduino's software serial port. I'm trying to throttle back the amount of data that it's sending using the $PSRF1xx commands from the NMEA protocol.

But... it's ignoring me. I've tried putting it into debug mode, but it ignores that too. :frowning: I have the GPS connected to the USB to serial converter used to program a lillypad. I can see the NMEA sentences fine. What am I doing wrong?!?!?

Here are the commands I'm trying to send:

$PSRF103,00,00,05,0020
$PSRF103,01,00,10,00
25
$PSRF103,02,00,10,0026
$PSRF103,03,00,10,00
27
$PSRF103,04,00,10,0020
$PSRF103,05,00,10,00
21

And here's the command to turn debug on that I'm trying:

$PSRF105,1*3E

Any help at all would be appreciated! :smiley:
Jules.

anyone? beauler?

Check your checksum, (I'm too lazy to do it for you) as i have found that this is the most common reason for commands not being accepted.

I haven't tried this on arduino BUT when I try and use a GPS I have to have a CR and LF at the end of each request

"$PSRF103,00,00,00,0124",CR,LF 'GGA
"$PSRF103,01,00,00,01
25",CR,LF 'GLL
"$PSRF103,02,00,00,0126",CR,LF 'GSA
"$PSRF103,03,00,00,01
27",CR,LF 'GSV
"$PSRF103,04,00,00,0120",CR,LF 'RMC
"$PSRF103,05,00,00,01
21",CR,LF

hope this helps