I did a tutorial a while back for Oleg's 0.19 firmware to get the GPS to sync the internal time to the GPS. it is in Message:
Basically, the linux operating system compares the current system time with the received GPS time. If the times are too different, linux will not update the system time when a new GPS time is received. I presume this is so linux will not change the time at all to the GPS time if it seems the GPS time is too far out of sync.
There is a minor change that can be made to the NTP time syncing software parameters that will force the system time to be synced with the GPS time, no matter how far off the GPS time is.
Here is a copy of the tutorial I posted for Oleg's 0.19 version. Hopefully, it will also work for George's firmware:
I had the GPS working with the X6100 with Version 0.18, months
back. I just installed Version 0.19, and it works with both of my GPS
Dongles. Here are some hints and requirements on getting the GPS to sync
the time in Oleg's software:
1) First, the GPS
must be plugged into the X6100 before powering it up. I believe Oleg
indicated this is so the software can detect that there is a GPS
installed during power up, so it can configure the Linux system to
handle GPS signals. So, first install the GPS Dongle in the Host USB
port with power off.
2) Next, check that the
X6100 is properly receiving the GPS signals from the GPS Dongle. Turn on
power, and wait for the display to show the spectrum, indicating the
X6100 is powered up and operating normally. Press the APP button. Select
the? GPS button. On the screen, you will see several fields for the
GPS. There are two important ones, "Fix" and "Date, time." If there is
no data in the Date/Time field, the GPS is not receiving even one
satellite, or the GPS hasn't warmed up yet, or the software is not
receiving the time/location message from the GPS. If the Date/Time field
has today's UTC (Zulu) date and the UTC time looks about correct, the
GPS and the software are probably working correctly.
3)
Next, the Fix field can have one of three values, "None," "2D" and
"3D." With a good UTC time, None probably indicates that the GPS has not
received enough satellites yet to do even an approximate location. When
the Fix field indicates None, the software time will not update the
System Time to the GPS UTC time. The Fix field must show 2D or 3D to
allow the GPS time to update the system time. There are several reasons
the Fix field may indicate None. The most common are that either the GPS
is still initializing, or that it can't see enough satellites. So,
first move the GPS/X6100 to a place where it has a good view of the sky.
Then, wait for the GPS to indicate a GPS Fix of 2D or 3D. It may take a
while for the GPS to initialize, so give it several minutes, and
depending on the GPS, it may take the same time to initialize every time
you turn on power, though it is usually a lot faster after the first
time.
4) Once the GPS app indicates a good UTC
time and a Fix of 2D or 3D, the software sends the UTC time from the GPS
to the Linux system. The Linux system will compare the GPS time against
its own internal system time. If the times are "close," within several
hundred seconds or so, it will initialize the system time to the GPS
time, then start tracking the GPS time, so the system time is always
"synced" with the GPS time. So generally, you should see the system time
in the upper right of the screen sync a few seconds after the Fix shows
2D/3D. And, the GPS time should track within one displayed second of
system time until you turn off the system.
5)
Finally, Linux has one "gotcha" for the time syncing. Linux is set up so
that a bad GPS time doesn't set the system time to the wrong value, if
the system and GPS times are way off. So finally, if the system time
doesn't sync with the GPS time, check that the system time is close to
the GPS time. First, still on the GPS App screen, write down the UTC
Date and Time. Then, press the APP button, then the APP 1:2 button to
get to the APP 2:2 screen. Then press the Settings button. Change the
Day, Month, Year and Hour, Min fields to the GPS UTC values you wrote
down (you don't have to update the Sec field, as the times will be close
enough). Linux will then try to sync the system time to the GPS time,
usually within a few seconds. If they don't sync, try turning off the
power and then turn it on again.
So, to summarize:
Turn off power
Plug in the GPS Dongle
Turn on power
Go to the GPS App
Wait for the GPS to get a 2D or 3D fix
If the times don't sync, manually update the System time to agree with the GPS time
If this doesn't work, you will probably need to ask for help from Oleg.
One
final thing: A while back, when Oleg first installed the GPS function, I
couldn't get my GPS to sync the system time. Oleg and I had a
discussion about this on this Forum. That's when I/we found out about
the times not syncing if the times are too far apart (see above). I dug
into Linux and found a parameter I could change in a Linux configuration
file that would allow Linux to force an initial sync of the times once
the Fix is 2D/3D, no matter how far apart the times are. I just tried
patching the configuration file and the patch still seems to be working.
However, I don't know enough Linux to know if there are any side
effects to this change.
I hope some of the above (long) descriptions/instructions are helpful to someone else.
Jerry K6ANI
