-* Time
+* Time Tracking
This document was created by Steven Baltakatei Sandoval on
~2020-07-23T22:27Z~ under a [[https://creativecommons.org/licenses/by-sa/4.0/][Creative Commons BY-SA 4.0 license]]. It
-was updated by Steven Baltakatei Sandoval on ~2020-07-25T19:34Z~
+was updated by Steven Baltakatei Sandoval on ~2020-10-13T18:02Z~
+
** Development Task list
*** Set up prototype unit
**** DONE Solder wire for PPS signal
- [[https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html][GPSD dev ref]] page for ~gpsd~ interfacing with ~ntp~.
- [[https://raspberryautomation.com/connect-multiple-ds18b20-temperature-sensors-to-a-raspberry-pi/][Raspberry Autom]] article on specifying custom GPIO pin.
*** Document prototype unit
+**** Summarize setup steps
+***** Perform main setup steps
+***** Install time-specific apps
+: $ sudo apt install usbmount eject gpsd gpsd-clients python-gps pps-tools ntp
+
+Explanation:
+
+- ~python-gps~: (Add explanation here)
+- ~pps-tools~: Package containing ~ppstest~ command useful for
+ checking status of PPS devices.
+- ~ntpsec~: Security-hardened version of ~ntp~, the Network Time
+ Protocol package. Useful for automatically setting the system clock
+ according to time servers or local hardware.
+
+
+**** TODO Integrate DHCP details from gregledet tutorial
+http://www.gregledet.net/computers/building-a-stratum-1-ntp-server-with-a-raspberry-pi-4-and-adafruit-ultimate-gps-hat/
+**** TODO Note working ntp.conf file
+
+#+BEGIN_EXAMPLE
+# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
+
+driftfile /var/lib/ntp/ntp.drift
+logfile /var/log/ntp.log
+
+# Leap seconds definition provided by tzdata
+leapfile /usr/share/zoneinfo/leap-seconds.list
+
+# Enable this if you want statistics to be logged.
+statsdir /var/log/ntpstats/
+
+statistics loopstats peerstats clockstats
+filegen loopstats file loopstats type day enable
+filegen peerstats file peerstats type day enable
+filegen clockstats file clockstats type day enable
+
+
+# You do need to talk to an NTP server or two (or three).
+#server ntp.your-provider.example
+server time.nist.gov iburst minpoll 5 maxpoll 5
+server tick.usno.navy.mil iburst minpoll 5 maxpoll 5
+server 0.us.pool.ntp.org iburst minpoll 5 maxpoll 5
+server 0.us.pool.ntp.org iburst minpoll 5 maxpoll 5
+server 0.us.pool.ntp.org iburst minpoll 5 maxpoll 5
+server 0.us.pool.ntp.org iburst minpoll 5 maxpoll 5
+
+# pool.ntp.org maps to about 1000 low-stratum NTP servers. Your server will
+# pick a different set every time it starts up. Please consider joining the
+# pool: <http://www.pool.ntp.org/join.html>
+#pool 0.debian.pool.ntp.org iburst
+#pool 1.debian.pool.ntp.org iburst
+#pool 2.debian.pool.ntp.org iburst
+#pool 3.debian.pool.ntp.org iburst
+
+# PPS Kernel mode
+server 127.127.22.0 minpoll 4 maxpoll 4 true
+fudge 127.127.22.0 flag3 1 refid kPPS
+
+# GPS PPS reference (NTP2)
+server 127.127.28.2 minpoll 4 maxpoll 4
+fudge 127.127.28.2 refid SHM2
+
+# GPS Serial data reference (NTP0)
+server 127.127.28.0 minpoll 4 maxpoll 4 prefer
+fudge 127.127.28.0 time1 +0.593 refid GPS
+
+# Fix False tickers
+tos mindist 0.5
+
+# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
+# details. The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
+# might also be helpful.
+#
+# Note that "restrict" applies to both servers and clients, so a configuration
+# that might be intended to block requests from certain clients could also end
+# up blocking replies from your own upstream servers.
+
+# By default, exchange time with everybody, but don't allow configuration.
+restrict -4 default kod notrap nomodify nopeer noquery limited
+restrict -6 default kod notrap nomodify nopeer noquery limited
+
+# Local users may interrogate the ntp server more closely.
+restrict 127.0.0.1
+restrict ::1
+
+# Needed for adding pool entries
+restrict source notrap nomodify noquery
+
+# Clients from this (example!) subnet have unlimited access, but only if
+# cryptographically authenticated.
+#restrict 192.168.123.0 mask 255.255.255.0 notrust
+
+
+# If you want to provide time to your local subnet, change the next line.
+# (Again, the address is an example only.)
+#broadcast 192.168.123.255
+
+# If you want to listen to time broadcasts on your local subnet, de-comment the
+# next lines. Please do this only if you trust everybody on the network!
+#disable auth
+#broadcastclient
+#+END_EXAMPLE
+
+**** TODO Integreate References
+- Some explanations for ~time1~, ~flag1~, ~flag3~, ~refid~, etc. strings in ntp.conf: [[http://doc.ntp.org/4.2.8/drivers/driver28.html][link]].
+- NTP Basics (what "system peer" means): [[https://kb.meinbergglobal.com/kb/time_sync/ntp/ntp_basics][link]].
+- GPSD guide indicating PPS signals should be preferred over GPS signals: [[https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html#_feeding_ntpd_from_gpsd][link]]
+
** Narrative
The ~ninfacyzga-01~ device is equipped with an Ozzmaker BerryGPS-IMU
-module which provides time and location data to ~gpsd~. The time is
-provided by GPS satellites which themselves are [[https://science.nasa.gov/science-news/science-at-nasa/2002/08apr_atomicclock/][equipped]] with atomic
-clocks. This extremely accurate set of clocks are needed since a GPS
-receiver calculates its position in space using a General Relativity
+module which provides time and location data to ~gpsd~ and ~ntp~. The
+time is provided by GPS satellites which themselves are
+equipped [fn:nasa_20020408_atomicclock] with atomic clocks. This
+extremely accurate set of clocks are needed since a GPS receiver
+calculates its position in space using a General Relativity
calculation that uses the small variations in the time stamps received
from each satellite. This means that ~gpsd~ may be used to set the
system clock without a need for an internet connection to a default
Debian time server; ~ninfacyzga-01~ can be its own time server.
+
+[fn:nasa_20020408_atomicclock] Title:[[https://science.nasa.gov/science-news/science-at-nasa/2002/08apr_atomicclock/][Tick-Tock Atomic Clock]];
+Date:2002-04-08; Website:NASA.gov; [[https://web.archive.org/web/20100429141752/http://science.nasa.gov/science-news/science-at-nasa/2002/08apr_atomicclock/][Archive-link]]; Archive-date:
+2010-04-29
+
** Description
*** Hardware
Ozzmaker BerryGPS-IMU, Version 3
** Operating Procedures
*** Initial Startup
**** Install Raspbian 10 (Buster) onto a Raspberry Pi Zero W.
+
+
**** Install Hardware
See [[https://ozzmaker.com/forums/topic/connecting-gps-pps-pin/][this]] Ozzmaker forum topic about connecting the BerryGPS-IMU
~T_PULSE~ pin to GPIO 18.
projects / EVA-2020-02.git / blobdiff