Re: [gpsd-users] Speeding up autobauding

[Alexander Carver]

On 10/19/2012 11:14, Alexander Carver wrote:
> On 10/19/2012 05:40, Eric S. Raymond wrote:
> > Jonathan Fewtrell <address@hidden>:
> > > My app is primarily for AIS (so normally 38400 baud) but also handles
> > > GPS (normally 4800). Ideally I'd like to be able to start the
> > > autobauding at 38400, as 90+% of the time this will be the right
> > > value. Is this possible via the API?
> >
> > Not at rutine.
> >
> > > Alternatively, can I tweak the code myself to produce this result? I
> > > don't really want to do this as it would mean my having to distribute
> > > my own version of gpsd to users, when they might already be using the
> > > standard version. But I'll do it if necessary. Pointers on how to do
> > > so without messing up the code would be appreciated. Would it be as
> > > simple as changing the order of the members of the rates[] array in
> > > serial.c (around line 529)?
> >
> > Easier than that.  Build from souece; with fixed_port_speed=38400.
> >
> > But it would be more useful if we can figure out why autobauding slowed
> > down and how to fix it.  Could you run a bisection between 3.1 and 3.7?
> I can narrow that range down a bit for you.  I'm still running 3.4 with
> my receiver set for 38400.  Autobaud takes about five to six seconds
> before it captures the port data.

I should make one clarification that I forgot:  I removed many of the 
drivers that I don't use when I compiled.  In my case I only have 
Unknown, Generic NMEA, SiRF binary, and JSON slave compiled in.