Precision Timekeeping Fuckery

How it works

Services

• gpsd
• chrony
• telegraf
• influxdb
• grafana-server
• syslog-ng

Testing

Status (Everything)

• bash ~/Precision-Timekeeping-Fuckery/full_status.sh

Status (Services)

• bash ~/Precision-Timekeeping-Fuckery/status_services.sh

Test PPS

• sudo ppstest /dev/pps0

Logs Stuff

Chrony Logs

• sudo tail -f /var/log/chrony/tracking.log
• sudo tail -f /var/log/chrony/statistics.log
• sudo tail -f /var/log/chrony/measurements.log

Telegraf Logs

• sudo tail -f /var/log/telegraf/telegraf.log

Grafana Logs

• sudo tail -f /var/log/grafana/grafana.log

Influxdb Logs

• sudo tail -f /var/log/syslog

Root Crontab Logs

• sudo tail -f /var/log/root-crontab.log

Setup

Requirements

1. Raspberry Pi with
   1. Raspberry Pi OS Light Version Installed
   2. SSH Access
   3. sudo permissions
2. A timing specific GPS module, wired to the Raspberry Pi GPIOs:
   1. GPS GND to RPi Physical Pin 6 (GND)
   2. GPS RX to RPi Physical Pin 8 (GPIO 14 / TX (UART))
   3. GPS TX to RPi Physical Pin 10 (GPIO 15 / RX (UART))
   4. GPS PPS to RPi Physical Pin 12 (GPIO 18)
   5. GPS VIN to RPi Physical Pin 27 (3.3 volts)
3. I2C RTC Module
   1. RTC GND to Rpi Physical Pin 9 (GND)
   2. RTC SDA to RPi Physical Pin 3 (GPIO 2 / SDA1 (I2C))
   3. RTC RCL to RPi Physical Pin 5 (GPIO 4 / SCL1 (I2C))
   4. RTC VCC to RPi Physical Pin 1 (3.3 volts)

Install

Hardware

1. pi4/5 and stuff for it
2. gps timing module
3. rtc
4. battery for rtc
5. wires

Wiring

Pins and Wiring Guide

OS

1. Raspberry Pi OS 64 bit lite
   1. Raspberry Pi imager
   2. Configure in imager
      1. hostname: grandmasterclock
      2. enable ssh
      3. ssh key
      4. username
      5. password
      6. locale
      7. keyboard

Software (Auto)

WILL REBOOT IN BETWEEN EACH COMMAND

1. curl -s https://raw.githubusercontent.com/PrincessPi3/Precision-Timekeeping-Fuckery/refs/heads/main/installer_auto.sh?nocache=$RANDOM | $SHELL
2. git -C ~/Precision-Timekeeping-Fuckery pull; bash ~/Precision-Timekeeping-Fuckery/installer_auto.sh
3. git -C ~/Precision-Timekeeping-Fuckery pull; bash ~/Precision-Timekeeping-Fuckery/installer_auto.sh
4. git -C ~/Precision-Timekeeping-Fuckery pull; bash ~/Precision-Timekeeping-Fuckery/installer_auto.sh
5. git -C ~/Precision-Timekeeping-Fuckery pull; bash ~/Precision-Timekeeping-Fuckery/installer_auto.sh
6. git -C ~/Precision-Timekeeping-Fuckery pull; bash ~/Precision-Timekeeping-Fuckery/test.sh

Software (Manual)

Clone the repo
git clone https://github.com/PrincessPi3/Precision-Timekeeping-Fuckery.git ~/Precision-Timekeping-Fuckery

Run raspi-config

1. Interface Options->Serial Port
   1. Would you like a login shell to be accessible over serial?
   2. Would you like the serial port hardware to be enabled?
2. Advanced Options 1. A1 Expand Filesystem

update os and packages (will reboot when finished)
bash ~/Precision-Timekeeping-Fuckery/update.sh

install packages (will reboot when finished)
bash ~/Precision-Timekeeping-Fuckery/packages.sh

finish install (will reboot when finished)
bash ~/Precision-Timekeeping-Fuckery/installer.sh

check status of everything and test bash ~/Precision-Timekeeping-Fuckery/test.sh

navigate to http://<ip's ip>:3000
Upload ~/Garfana-Visualization.json to create dashboard

Clients

Windows

1. Open the Control Panel and navigate to the Date and Time settings.
2. Click on "Internet Time" and then "Change settings".
3. Enable the option to "Synchronize with an Internet time server".
4. Choose a time server from the available list or enter a custom one.
5. Click "OK" to save the changes.

Links

Helpful Guide https://austinsnerdythings.com/2025/02/14/revisiting-microsecond-accurate-ntp-for-raspberry-pi-with-gps-pps-in-2025/

Current Module

• Chipset https://www.u-blox.com/en/product/neo-f10n-module
• Breakout https://docs.sparkfun.com/SparkFun_u-blox_NEO-F10N/single_page/

Next Module

• Chipset https://www.u-blox.com/en/product/neolea-m8t-series
• Breakout https://www.ebay.com/itm/134243322249

U-Blox Software (U-Center) https://www.u-blox.com/en/product/u-center

todo

• case
• gps sma antenna adaptor
• change gps settings
  • use 5v
  • adjust time delay to be closer to
  • higher baudrate
    1. 460800
• README
  • installer1-4.sh
    • sudo apt update && sudo apt install -y git
    • git clone https://github.com/PrincessPi3/Precision-Timekeeping-Fuckery.git ~/Precision-Timekeeping-Fuckery
    • cd ~/Precision-Timekeeping-Fuckery
  • grafana
    • url
    • default login
    • import
    • data source
    • fix
    • current
      • connections->data sources->add data source->influxdb
        • url http://127.0.0.1:8086
        • timeout 5
        • database Chrony_Stats
        • save and test
        • new dashboard
        • import a dashbboard->Garfana-Visualization.json
        • edit and update each pannel
        • save dashboard
• Raspberry OS Lite
• Document scripts
  • chrony_statistics.sh
  • services.sh
  • test.sh
  • cleanup.sh
  • dump_configs.sh
  • nuke_logs.sh
  • reconfig_full.sh
• link to docs of all the services and tools
  • influxdb
  • chrony
  • gpsd
  • telegraf
  • garfana
  • syslog-ng
  • u-blox software
  • modules
    • chipsets
      • datasheet
    • specific boards
      • datasheet
• installer with reboot cron for sequence?

notes: gps cable delay : RG-85 : 0.051 ns/cm 10ft in cm: 304.8 gps cable delay: 304.8*0.051 = 15.5448ns, round up to 16ns

known bugs