[time-nuts] Lucent KS-24361 REF 0 standalone
paulswedb at gmail.com
Fri Feb 10 12:24:04 EST 2017
There was a fellow time nut that created an Arduino that would control the
unit. It faked out what the GPS sent so the unit thought it was connected
to a complete system. It works very well the the quality of the unit simply
depends on the quality of the 1 pps from the GPS receiver chosen. I used
some NEOs but it sounds like there are better receivers.
On Tue, Feb 7, 2017 at 5:39 PM, Thomas Petig <thomas at petig.eu> wrote:
> Thank you for your reply.
> As always, the solution appears after sending the mail on the list. I
> send a wrong character for terminating the message and therefore the REF
> 0 was confused when the message ends (it expected 0x0D 0x0A, but got
> 0x0D 0xA0 from me).
> It seems that in pForth, pr_gps_debug will count this as frame error.
> Regarding my setup, I am sending the Oncore messages from Python via a
> USB cable. I just trigger the Python script on the PPS, I don't read the
> actual what the skytraq sends. It seems the REF 0 is happy with the
> timing of my Oncore messages.
> On Mon, Feb 06, 2017 at 03:40:23PM -0500, Bob Camp wrote:
> > Hi
> > The only serial dialog between the two units is a repeat of the output
> of the
> > GPS module. My guess is that there is some subtle difference between
> > the Oncore data and they skytraq….
> > Bob
> > > On Feb 6, 2017, at 1:23 PM, Thomas Petig <thomas at petig.eu> wrote:
> > >
> > > Hi everyone,
> > > I am currently trying to repeat previous work of members of this list
> > > convincing the REF 0, to run standalone with a given 1PPS signal from a
> > > gps. Similar to:
> > > https://syncchannel.blogspot.se/2015/08/standalone-
> > >
> > > I am using a skytraq gps with 100ms, 74AC04 for inverting and level
> > > shifting and I added the jumper wires on J5. I simulate the Oncore
> > > messages with a python script using a usb->uart cable and triggering on
> > > the 1PPS pulse on the CTS line. I am sending @@Ea, @@En, @@Bb, @@Ap,
> > > @@Aw, @@Ag, @@At, @@Az, @@Bj, @@Bo with a delay of 75 ms, as suggested
> > > in the blog above:
> > > https://github.com/thpe/oncore/blob/master/oncore_emu.py
> > >
> > > Surprisingly, I have a constant delay of 0.8 ms, and only a jitter of
> > > +/-0.1 ms for the oncore messages compared to the pulse on the CTS
> > >
> > > Short everything is working and if I force external 1PPS usage it locks
> > > to it (NO GPS light goes off). Using pForth:
> > > 1 force_ext_1pps
> > > 1 force_gps_1pps
> > >
> > > But, it does not do it on its own, since it ignores the tracking mode
> > > for the satellites and, I guess after reading the Z3801A manual,
> > > therefore it claims the GPS 1PPS signal as invalid. E.g., for the entry
> > > with @@Ea:
> > > 0x02, 0x08, 0xFF, 0x82
> > > meaning satellite 2 in mode 8 (used for positioning) it assumes mode 0.
> > > The other values, like signal strength 0xFF and channel status 0x82 are
> > > taken, even if I change them to something else. The mode value is
> > > ignored no matter what it says.
> > >
> > > In the attached files on sees that "GPS 1PPS Invalid: not tracking",
> > > the mode of the is 0. I forced it to use the external 1PPS signal.
> > >
> > > So, the question what tiny detail did I miss while reading the mailing
> > > list archive and those blogs on how to set the REF 0 up for standalone
> > > operation just using the Oncore messages?
> > >
> > > Does someone has dump of the communication between REF 1 and
> > > REF 0, until the REF 0 is happy (I don't have a REF 1)?
> > >
> > > Regards,
> > > Thomas
> > > DK6KD
> > > SA6CID
> > > <pstat.txt><print_stat.txt>_________________________________
> > > time-nuts mailing list -- time-nuts at febo.com
> > > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > > and follow the instructions there.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> and follow the instructions there.
More information about the time-nuts