James Hartley wrote:
On 4/11/07, Marc Balmer <[EMAIL PROTECTED]> wrote:
When you use cu or tip directly on the serial line, do you see any NMEA
0183 sentences?
Thanks to both you Marc & Otto. Your comments have helped with a number of
questions. I'm currently questioning the power supplied to the Garmin
which
The Garmin GPS18 LVC needs 5V power supply. I used a free USB port to
"steal" it.
I will get to tomorrow. For now, I've gone back to my T43 laptop where I
have a USB Delorme GPS LT-20. I can now see the sensor as well as NMEA
sentences through cu there.
Three questions.
I'm still not seeing anything appear in /var/log/daemon. How soon should
log messages appear?
From the archives, I remember a statement made that without a pulse per
second (PPS) signal, a GPS unit would only be able to minimally coordinate
the time through ntpd. This statement was also made in reference to a USB
unit. Are PPS signals inherent to all GPS units but are lost through an
USB
interface? Is there something within the NMEA sentence traffic which
should
tell me that I have a PPS signal?
Not all GPS receivers have a PPS signal. If you use -current, the time
information is quite precise, even w/o PPS (you will be off by 100-200
ms). And no, you will not see in NMEA traffic if there is a PPS signal.
And one last thing: You need to program you GPS unit to actually issue
the PPS signal.
Thanks again for your clarifications.
You're welcome, but make sure you read the documentation of your Garmin
unit.
