[gpsd-users] An endian problem?

[Chris Howard]

Hi,

I am new to gpsd and this may turn out to be the wrong place for my question.

I have a Trimble Resolution-T GPS which I have incorporated into a gps 
disciplined
oscillator, sort of a home-brewed Thunderbolt.

I'm looking at the TSIP data coming out of the thing.

First, let me say that the windows program which I downloaded from Trimble
appears to talk to it just fine.  That's on my windows PC.

But my problem comes when I try to use a BeagleBone single board computer
which is running debian linux.

So my lash-up is the Trimble Resolution-T GPS talking to the BeagleBone.
The BeagleBone has multiple serial ports.  I am successful in talking
to various other boxes through this same serial port.  I can use minicom,
or other programs, seems to work ok.

I have two programs on the BB which claim to understand TSIP: ntpd and gpsd.
Neither will talk to this GPS.

So I decided to drill down into the TSIP protocol a bit and see what's wrong.

I gathered some data directly from the serial port using cat into a file.
I look at the file with 'od -x'.

Here's where we are getting to the strange part.  My packets only look right
if I swap bytes:

dd if=<serial port>  of=gps.datafile  conv=swab

I am flummoxed.  Is there some config on the Resolution-T which will send
data in swapped format?  Is there something really wrong with my BB serial
port (seems unlikely)?

Ok... so I'm wondering if there is some way to do this byte swapping on
the fly.  I created a named pipe (fifo) and put my dd command output
there.  Gpsd didn't want to read from that because it's not a serial port.

Is there some way to get gpsd to read from a stream?

Resolution-T config?
Can gpsd read from a stream?
My own ignorance?

Thanks

Chris