Help With Getting PPS( Pulse Per Second) Working With Chrony

The Doktor

New Member
Mar 12, 2024
1
0
1
Hi, I'm very new to proxmox and kind of new to Linux, and I need a bit of help. I am setting up an N 100 based mini computer(often referred to as firewall appliance) using the recently released Tomato64 https://tomato64.org/ router firmware. I have already got the VM's for tomato, as well as FreePBX Set up and operating perfectly. I was kind of amazed just how easy proxmox was to set up. But now I've got something I'm having trouble with.

I wish to use Chrony on the host as my network time server, this proved to be no problem. I also wish to synchronize this time server with my GPSDO, which I have been attempting for several days now with no success. I've got the signal converted to serial port levels, and I'm feeding both the PPS and the NMEA data into the serial port located at /dev/ttyS0. The data is coming in okay, If I run gpsmon it gives a bunch of data, although the PPS field is left blank. If I run ppscheck, I get the following.

root@Proxmox:~# ppscheck /dev/ttyS0
# Seconds nanoSecs Signals
1710519439.933917435 TIOCM_CD
1710519440.001331406
1710519440.101356544 TIOCM_CD
1710519441.001316803

I have edited /etc/default/gpsd to include DEVICES="/dev/ttyS0" And then rebooted, but trying to run ppstest /dev/pps0 receives a bunch of timeouts. I have also tried pps1 with the same results. If I "stop systemctl stop gpsd.socket gpsd.service" And then try "gpsd -D 5 -N -n /dev/ttyS0", I get a bunch of data which includes

gpsd:ERROR: unable to connect to the DBUS system bus
gpsd:pROG: shmget(0x47505344, 24512, 0666) for SHM export succeeded
gpsd:pROG: shmat() for SHM export succeeded, segment 8
gpsd:INFO: stashing device /dev/ttyS0 at slot 0
gpsd:pROG: no /etc/gpsd/device-hook present, skipped running ACTIVATE hook
gpsd:INFO: SER: opening GPS data source type 2 at '/dev/ttyS0'
gpsd:INFO: SER: speed 9600, 8N1


I believe the "gpsd:ERROR: unable to connect to the DBUS system bus" Is because I have no desktop present, if I understand that correctly.
I am not sure what "gpsd:pROG: no /etc/gpsd/device-hook present, skipped running ACTIVATE hook" is all about, is this a problem?

and Further down in the output

gpsd:INFO: startup at 2024-03-15T16:29:12.000Z (1710520152)
gpsd:pROG: KPPS:/dev/ttyS0 assert 0.000000000, sequence: 0, clear 1710520153.001330528, sequence: 1 - using: clear
gpsd:pROG: KPPS:/dev/ttyS0 Clear cycle: 1710520153001330, duration: 1710520153001330 @ 1710520153.001330528
gpsd:pROG: PPS:/dev/ttyS0 Clear cycle: 1710520153001330, duration: 1710520153001330 @ 1710520153.001330528
gpsd:pROG: KPPS:/dev/ttyS0 assert 1710520153.101386295, sequence: 1, clear 1710520153.001330528, sequence: 1 - using: assert
gpsd:pROG: KPPS:/dev/ttyS0 Assert cycle: 1710520153101386, duration: 100055 @ 1710520153.101386295
gpsd:pROG: PPS:/dev/ttyS0 Assert cycle: 1710520153101386, duration: 100055 @ 1710520153.101386295
gpsd:pROG: PPS:/dev/ttyS0 Assert ignored missing last_fixtime
gpsd:IO: UBX: len 60

This seems to indicate to me that the kernel PPS module is loaded and sees /dev/ttyS0. And yes, I believe the signal high and low are reversed coming into the port. That needs to be fixed, but I don't think it's a problem with getting it working. At some point during the output, I get a timeout error, after that all the outputs is a timeout error every few seconds. Not sure what to make of this.

Nothing I have tried gets me to see a signal at /dev/pps0, and I have had no luck getting any information into Chrony except by synchronizing to online servers or a raspberry pi NTP server I currently have running.

I would appreciate any help any of you can give with getting the time data and PPS into Chrony (or ntpd). I also wish to make GPSD accessible over the network, As I need to connect a program called "Lady Heather" http://www.ke5fx.com/heather/readme.htm so it can get information about the GPSDO.


Any help or nudge in the proper direction appreciated.
Ed
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!