Re: [gpsd-users] 1 PPS and Ubuntu11.10 serial port problem

[Robert Livingston]

Gary,

The PPS is there (driving a rubidium standard and a timing interface) 
but the Resolution-T output level is CMOS, approximately 2 V.  That is 
undoubtedly the problem with the RS232, and it is relatively simple to 
remedy in hardware.  II had hoped that an industrial computer RS232 UART 
might be more forgiving, but I just tested it using a +-5V (short run) 
RS232, and it does not even respond to that.

Thanks for the tip.  GPSD is an amazing piece of work, and your user 
group support is extraordinary.

Regards,
Robert

Gary E. Miller wrote:
> Yo Robert!
>
> On Wed, 01 Feb 2012 19:46:11 -0800
> Robert Livingston <address@hidden> wrote:
>
>   
> > Thanks for the comments.  Swiping the testing version of 3.4.1 from 
> > Debian testing (along with a couple of other packages) runs on Ubuntu 
> > 11.10 and the "not-online" errors disappear.
> >     
>
> Good.
>
>   
> > NTP works with the GPS as before, and as Hamish points out, that may
> > be sufficient.  However, I'd like to use the 1 PPS in addition but
> > the serial port never seems to see the CD pin signal.  In previous
> > (older version) cases, the CD interrupt was noted in the -D5 list,
> > and I see none now.  Have you seen cases where the UART is masking
> > the interrupts, an is there a way to see if that is the case?
> >     
>
> The most common problem is the PPS level is not real RS-232.  Are
> you sure your output is going from -12V to 12V and back again?
>
> Also some GPS need to be told to output PPS signals.
>
> So best to put an oscilloscope on the pin if you can.
>
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
>         address@hidden  Tel:+1(541)382-8588
>