[ntp:questions] What is the NTP recovery time from 16s step in GPS server?
david-taylor at blueyonder.co.uk.invalid
Wed Oct 31 18:29:15 UTC 2012
On 31/10/2012 17:22, Rob wrote:
> I see errors that are related to permission.
I had wondered about that as well...
> I would recommend to type in the session before you do anything else:
> sudo sh
> or: sudo bash
OK, I can try that.
> When it works ok you should have a shell running as root, and then
> you can stop the service and start gpsd without the risk that you
> start to run it as user 1000 (which appears to be happening according
> to the logs), and this user probably is not allowed to use the serial
> There are various things you could do to allow serial port access for
> the user, but it should not be required as gpsd normally starts as
> root to open the port and then changes to user nobody for its server
> Is /dev/ttyACM0 the name for the USB serial port? Is there a
> /dev/ttyUSB0? Maybe you could try that.
> Using USB ports in a service started at boot time should normally
> work ok, but when it has issues on the Raspberry maybe it could
> be solved by delaying the startup of gpsd a bit. But don't try to
> tackle all issues at the same time.
> The log output of the Time with offset 16 is OK. What does it
> show when you powercycle the receiver?
I appreciate you taking the time to comment, Rob.
Ignoring the offset for the moment, if I power up the Rasberry Pi from
cold while it sees the PPS signals (to an interrupt-driver GPIO pin) is
never sees gpsd data ( and trying cgps -s also times out with a can't
connect). I've left it for about 30 minutes but gpsd never sees data.
When I then do a warm reboot NTP sees data from gpsd right away and cgps
-s works as well.
My feeling is that I should concentrate on getting the PC to see GPS
cold from a cold boot first, and then worry about any 16-second step.
Would you not agree? If so, what magic file to I have to edit and how
to delay gpsd starting?
Actually, I'm not even sure myself, as I recall that from a cold boot,
stopping and restarting gpsd isn't enough to start the data flow, the
GPS receiver itself has to be plugged out and back in, but I'm happy to
try a delayed gpsd start.
What do you think?
More information about the questions