[time-nuts] TU60-D120-041 power up

Hal Murray hmurray at megapathdsl.net
Wed Oct 22 16:20:25 EDT 2014


sjdehaven at gmail.com said:
> I think you pointed out that this GPS unit defaults to the Navman Binary
> mode.  I have tried to use HyperTerminal via a serial port and about all  I
> see is @@EA followed by a burst of random characters every second.  I  tried
> 4800 and 9600 baud.  I would like to be able to read the NMEA  sentences
> (GPGSA, etc) so I can use Day, Date, Time and 3D Fix for other  purposes.
> To do that I think I need to change the format of the GPS  output data.
> (From Navman Binary to ????)

Things like @@Ea are probably Motorola/Oncore rather than Navman.  I'm not 
familiar with Navman, but I found one web page on their site about the SiRF 
binary protocol.

For things like this, my first try is usually gpsmon from the gpsd package.  
It's very good at figuring out what type of device you have.

By default, "gpsmon /dev/ttyXXX" (for whatever the filename is on your setup) 
will try various baud rates and such until it recognizes something.  Then it 
decodes and displays the data.  By default it doesn't change the speed or 
mode.

There is a command to switch to/from NMEA and binary modes, and a command to 
change the baud rate.

There is another command to try harder to discover the device type.  That 
sends commands that might confuse/break some devices.

Switching to NMEA mode may get lost when you reset or power cycle the device. 
 It will probably stick around long enough for you to debug the next layer of 
software.  You can probably find the command to switch-to-NMEA in the gpsd 
sources.

-- 
These are my opinions.  I hate spam.






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