-* 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 ~2020-10-12T22:22Z~
+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
** 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.