what is needed for Vk-172/Vk-162 Cold Boot

[klintkrossa]

Hello,
Well back to start, AAAAAAGGG. I am trying to make a stratum style clock with a Vk172 dongle. This dongle uses a uBlox7 chip. That chip is in the Adafruit gps /w pps. I did a warm start it worked with the program that I have. I did a warm start to test it.
Now I can not even get the GPS to start. I have even tried to do a warm start, to know effect.

What commands are needed to "cold start" the uBlox7 chip?
(Please be kind with the description, as I know very little on what to send and what coding is needed.)

I did find some stuff on the chip in one of the forums but no cold start.
viewtopic.php?f=28&t=123989
Klint

[scruss]

How many satellites was it seeing the last time you used it? If it can't see enough satellites, it won't cold boot.

[klintkrossa]

Hello,
I think 6 satellites. the time is not set either it is at epoch.

[IanS]

This is how I got mine working, which is certainly UBlox, and I think a VK-172. The systemd controlled gpsd does not seem to cooperate very well

/etc/default/gpsd:
Set start_daemon to false to deactivate this activation method.

Code: Select all

# Default settings for the gpsd init script and the hotplug wrapper.

# Start the gpsd daemon automatically at boot time
START_DAEMON="false"

# Use USB hotplugging to add new USB devices automatically to the daemon
USBAUTO="true"

# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
DEVICES="/dev/ttyACM0"

GPSD_SOCKET="/var/run/gpsd.sock"

# Other options you want to pass to gpsd
GPSD_OPTIONS="-n"

Within /etc/rc.local:
The -n option is important, as this activates the daemon without needing some other GPS client to send it a query first. This might be what you need to restart the device.

Code: Select all

/bin/systemctl stop gpsd.socket
/bin/sleep 1
/usr/sbin/gpsd /dev/ttyACM0 -n -F /var/run/gpsd.sock
/bin/sleep 1
/usr/sbin/service ntp restart

Within /etc/ntp.conf

Code: Select all

# Use GPS receiver
server 127.127.28.0 prefer
fudge 127.127.28.0 time1 0.0 refid GPS
# GPS PPS reference, if provided by GPS device
server 127.127.28.1 prefer
fudge 127.127.28.1 refid PPS

The ntp.conf section came at least partly from https://blog.logentries.com/2015/07/add ... e-to-ntpd/, but I cannot remember where I got the info about not using systemd for gpsd. I do know that the tell-tale symptoms of systemd getting it wrong is that the gpsd port was owned by the wrong process. i.e. 'sudo netstat -pant' would show that port 2947 was owned by process 1 (init) instead of by gpsd.

[klintkrossa]

Thanks,
I'll try that.