Re: LF: Octo-soundcard for the Raspi, another question

[Paul Nicholson <vlf0403@abelian.org>]

Looks like you got a result on the dropouts.  Worth feeding back to
the manufacturer - if anyone is still there.

48k/sec sampling should be fine, I haven't tested it on the Octo yet.

Does the problem appear at 48k/sec when it gets hot enough?
It probably needs to work up to 40C or more to be robust in the field.

The DC/DC converter sounds marvelous - please tell us the part number!

> Still need to manage to set the clok by gpsd,

If not done already, install ntp with

 sudo apt-get install ntp ntpdate

and gpsd with

 sudo apt-get install gpsd

Then you just need some magic entries in the config file
/etc/ntp.conf, find the bit that lists the servers, comment
them all out with a # and put in

 server 127.127.28.0 minpoll 4 maxpoll 4
 fudge 127.127.28.0 time1 0.051 refid GPS

The time1 parameter is in seconds, tells gpsd roughly what
the serial/USB comms delay is so that it can correct for it.
You can tune that number after you get vttime running but it
is not very important.

Reboot for the change to take effect.  Then the command

 ntpq -p

to list the time sources, will show the GPS and time offset and jitter.

It should have a '*' against it which indicates that ntp is using it.

--
Paul Nicholson
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