Hi Stefan thanks for the advice.
I also found online those additional steps to stop and disable
the gpsd socket and then to start manually. I found a lot of info
for using the RaPi as an NTP server in David Taylor's satsignal.eu
website. I'm assuming when installing ntp and gpsd, autostart
commands were placed in a boot configuration file - I'm still
looking for it....
I see from ntpq - p that you left the on-line ntp servers
operational, in addition to your gps (I understood Paul's email to
disable external ntp by removing these lines as part of the
ntp.conf modification)
My gps USB id =ACM0.
Unfortunately, even with all this advice, still no sign of gps
synchronisation....but this has helped confirm I have set-up the
basic system correctly, so it must be a simple error..and I have
plenty of time!
In your photo of the complete assembly, it is interesting to see
your modifications. I can see clearly the gps interface connected
to the RaPi gpio pins extended through the Octo board. It looks as
though you have made your own interface plug for the input of the
Octo and using only Ch1, Ch2 with Ch3 as PPS?.
What are the two vertical boards on the left? the smaller one
looks like (but not exactly) the DC/DC inverter. Also a direct
power connection to the RaPi, as you are not using the microUSB
power connector.
Have you added the modifications to give the RaPi a "soft" on/off
switch (to protect the SDCard) and a reset button?
Finally, I see you have a USB plug connected - is this for the
wifi? I think you are using a RaPi2 without an onboard wifi..and I
remember from your earlier posts that you are using 2.4 GHz WiFi
to link from your remote forest listening post back to your main
site in the University. This must be a LoS path? Even so, quite
impressive to work with the interference from the mass of other
Wifi in the city... It gives me the thought to run a RaPi system
at my local radio club which is in a relatively radio-quiet site
outside the City of Doncaster. But this is about 12km away and not
LoS. It would be a good LF/VLF education for the members as their
main interest is microwave and nanowaves (light
transmissions).....
73 Terry
On 07/08/2017 14:49, DK7FC wrote:
Hi Terry,
Am 06.08.2017 13:07, schrieb Terry G0EZY:
Hi Stefan
Did you get gpsd and ntp working by following Paul's info (email
21/07)?
No, but his advice was an important step forward. I took
additional
advice from the web and after some time i got it working.
I have a UBlox NEO 7M connected to the RasPi by USB
and I
can run xgps or cgps and see that the NMEA is being read. But
ntp is
not being updated by the gps...
I'm using a NEO 6M and i used the serial interface on the GPIO
board.
You just need two short wires to realise the communication.
Like that:
http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/20170807_152938.jpg
I have been at the point where you are hanging now. The main steps
i
did to get it running were:
sudo
systemctl stop gpsd.socket
sudo
systemctl disable gpsd.socket
then start the service manually with:
sudo gpsd –n
-F
/var/run/gpsd.sock /dev/ttyAMA0
Replace AMA0
by your individual ID of the USB serial interface if you want
to use
that.
I added:
server 127.127.28.0 prefer
fudge
127.127.28.0 time1 0.055 refid GPS
to
/etc/ntp.conf
Afterwards
sudo
service ntp restart is required.
I checked if it works by running
ntpq
–p and
got this
result:
pi3@Pi8:~/script $ ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
*SHM(0) .GPS. 0 l 47 64 377 0.000 297.483 137.453
v20819.php-frie .STEP. 16 u - 1024 0 0.000 0.000 0.000
ole.klickmich.o .STEP. 16 u - 1024 0 0.000 0.000 0.000
ntp.fanlin.de .STEP. 16 u - 1024 0 0.000 0.000 0.000
+ptbtime1.ptb.de .PTB. 1 u 134 64 336 15.411 356.851 150.343
For my portable recorder i'm running a script that checks the
difference between system time and GPS time. It is running a while
loop
until the time difference becomes less than 2 seconds. This tells
that
the clock has been set by GPS. Then the script continues to start
all
the vt processes.
Soon i'm going to run an EbNaut transmission on 3675 Hz to see if
i can
decode it only by using vlfrx tools and EbNaut.
Once I have that problem solved and built the PPS
shaper,
I can make progress with the Octo soundcard project.
Paul made it seem so easy...!
Yes, if you know how it works then it appears to be easy. Like
driving
a car, or solving mathematic equations...
I followed your recommendation and bought some of
the
DC/DC converters from Amazon. Do they require any additional
filtering?
No additional filtering is required (i can't know about your
individual
situation however). Anyway i put 1000 uF onto the output, just to
be
prepared for any eventualities.
After years i did not discover QRM on LF/MF/VLF. I'm using this
converter on the tree as well.
73, Stefan
73 Terry
