* Location Logging
This document was created by Steven Baltakatei Sandoval on
-<2020-06-29 Mon 12:14> 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 <2020-06-29 Mon 16:05>.
+~2020-06-29T12:14Z~ 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 ~2020-06-30T19:44Z~
+#+TITLE: Ninfacyzga-01 Manual
+#+AUTHOR: Steven Baltakatei Sandoval
+#+EMAIL: baltakatei@gmail.com
** Narrative
Ninfacyzga-01 records (logs) its position in time and space using a
[[https://en.wikipedia.org/wiki/Satellite_navigation_device][GPS receiver]]. The NMEA location data produced by the receiver is
***** NMEA
See the [[https://en.wikipedia.org/wiki/NMEA_0183][Wikipedia page]] for this.
***** GPX
-See the [[https://en.wikipedia.org/wiki/GPS_Exchange_Format][Wikipedia page]] for this.
+See the [[https://en.wikipedia.org/wiki/GPS_Exchange_Format][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used.
***** KML
-See the [[https://en.wikipedia.org/wiki/Keyhole_Markup_Language][Wikipedia page]] for this.
+See the [[https://en.wikipedia.org/wiki/Keyhole_Markup_Language][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used.
**** Encryption Method
Files produced by the bkgpslog script are encrypted against a set of
-public keys using [[https://github.com/FiloSottile/age][age]]. The public keys are bech32 strings supplied as
-options to bkgpslog when called.
+public keys using [[https://github.com/FiloSottile/age][~age~]], a simple command line encryption tool
+selected over ~gpg~ because of ~age~'s deliberate lack of
+configurability.
+
+The public keys are bech32 strings supplied as options to bkgpslog
+when called. The secret key should *NOT* be stored in Ninfacyzga-01.
+
+If a key pair was generated using ~age-keygen~, then it is an [[https://en.wikipedia.org/wiki/Curve25519][~X25519~]]
+key pair. See the [[https://age-encryption.org/v1][~age~ Version 1 specification]].
+
+An ~ssh-rsa~ or ~ssh-ed25519~ SSH public key string may be used instead of
+the bech32 public key string produced by ~age-keygen~ for convenience.
+
+Help information for ~age~ is available by running ~$ age --help~.
+***** Encryption Commands
+Files may be encrypted to several recipients using a command similar to:
+#+BEGIN_EXAMPLE
+timeout "60s" gpspipe -r | gpsbabel -i nmea -f - -o gpx -F | age \
+-r age1kza7pfshy7xwygf9349zgmk7x53mquvedgw9r98qwyyqhssh830qqjzlsw \
+-r age1ce3pvzrqfcn2pc6zqzglc8ac8yjk3fzukpy08cesqjjwns53xywqmaq7xw \
+-r age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5 \
+> location.gpx.age
+#+END_EXAMPLE
+
+In this example, the strings beginning with ~age1...~ are
+bech32-formatted public key strings.
+
+
+***** Decryption Commands
+Files may be decrypted using a command similar to:
+
+#+BEGIN_EXAMPLE
+cat location.gpx.age | age -d -i key.txt > location.gpx
+#+END_EXAMPLE
+
+The version of ~age~ used to perform the encryption
** Operating Procedures
*** Initial Startup
+See OEM (Ozzmaker) [[https://ozzmaker.com/berrygps-berrygps-imu-quick-start-guide/][quickstart guide for the BerryGPS-IMU]].
+
+**** Physical Setup
+
+BerryGPS-IMU must be electrically connected to the correct pins on the
+GPIO header of a Raspberry Pi Zero W.
+
+*Optional*: stack together with PiZ Uptime 2.0 module. No GPIO pins
+conflict so a simple stacking and soldering with long header pins is
+possible.
+
+**** Software Setup
+***** Install Executables
+
+Install Raspbian 10 Buster onto an SD card image. See the Raspberry Pi
+Foundation [[https://www.raspberrypi.org/documentation/installation/installing-images/README.md][installation instructions]]. Configure WiFi to permit log
+file transfer. Configure SSH to permit remote administration via the
+command line interface.
+
+Make sure to install the ~unattended-upgrades~ package to make sure
+the latest security patches for packages are installed. See [[https://linux-audit.com/using-unattended-upgrades-on-debian-and-ubuntu/][this page]]
+for a description of how ~unattended-upgrades~ works.
+
+Install ~gpsd~, ~gpspipe~, ~git~, and this repository for location
+logging capability.
+
+Install ~syncthing~ for log file transfer capability.
+
+Place ~age~ binary (the one compiled for ARM CPU architecture for
+Linux) in ~$HOME/.local/bin~.
+
+***** Disable Swap File
+Since standard Raspbian 10 (Buster) install involves copying
+unencrypted file system image to SD card which is mounted by the
+Raspberry Pi, system memory may be written to disk in the form of a
+Swap file as described [[https://ideaheap.com/2013/07/stopping-sd-card-corruption-on-a-raspberry-pi/][here]]. In order to reduce the chance that
+location log data is ever written to disk, swap file functionality
+must be disabled[fn:ideaheap_20130731_disableswap].
+
+Raspbian 10 uses dphys-swapfile to manage a swap file. It may be
+disabled persistently[fn:rpf_20190702_disableswappersist] by running
+the following command:
+
+: sudo systemctl disable dphys-swapfile.service
+
+To view the status of the swap file in Raspbian 10, run ~free -m~:
+
+#+BEGIN_EXAMPLE
+pi@ninfacyzga-01:~$ free -m
+ total used free shared buff/cache available
+Mem: 432 86 36 21 309 268
+Swap: 99 0 99
+#+END_EXAMPLE
+
+After disabling the swap file and rebooting:
+
+#+BEGIN_EXAMPLE
+pi@ninfacyzga-01:~$ free -m
+ total used free shared buff/cache available
+Mem: 432 89 214 3 128 289
+Swap: 0 0 0
+#+END_EXAMPLE
+
+[fn:ideaheap_20130731_disableswap] Explanation:
+https://ideaheap.com/2013/07/stopping-sd-card-corruption-on-a-raspberry-pi/
+
+[fn:rpf_20190702_disableswappersist] Persistant disabling of swap in
+Raspbian 10 Buster:
+https://www.raspberrypi.org/forums/viewtopic.php?p=1490692&sid=5c596a124b7805d6b10dab8d3d7caf16#p1490692
+
+***** Automatic Start Configuration
+
+Edit the user cron job list with ~$ crontab -e~ to add the following
+lines:
+
+#+BEGIN_EXAMPLE
+0 * * * * /bin/bash ~/bkgpslog --output ~/dir
+
+@reboot /bin/bash ~/bkgpslog --output ~/dir
+#+END_EXAMPLE
+
+The first line will run ~bkgpslog~ at the start of every hour and save
+output files to the ~dir~ directory in your home folder.
+
+The second line will run ~bkgpslog~ when the system starts up.
+
+~/bin/bash~ tells ~cron~ to run ~bkgpslog~ with Bash.
+
+If encryption and compression are required, then the appropriate
+options must be added. The lines that must be added via ~$ crontab -e~
+may resemble:
+
+#+BEGIN_EXAMPLE
+0 * * * * /bin/bash ~/bkgpslog -c -e -r age1z2...qkv6p -o ~/dir
+
+@reboot /bin/bash ~/bkgpslog -c -e -r age1z2...qkv6p -o ~/dir
+#+END_EXAMPLE
+
+The ~age1z2...qkv6p~ is an ~age~ public key string. Please see the
+[[*Key Generation][Key Generation]] section for an explanation.
+
+The options are:
+
+: -c : tells bkgpslog to compress output
+: -e : tells bkgpslog log to encrypt output
+: -r : tells bkgpslog to interpret the next argument as a pubkey string
+: -o : tells bkgpslog to write output files to the directory represented
+: by the next argument
+
+***** Log Transfer Configuration
+Log files may be shared to other machines via ~syncthing~. See [[https://docs.syncthing.net/][this]]
+manual for how to set up a shared folder and add Ninfacyzga-01 as a
+device. Syncthing's directory synchronization capability allows a
+remote machine to delete files from Ninfacyzga-01 by deleting from the
+shared folder that they both share.
+
+When log files are removed from Ninfacyzga-01 is not within the scope
+of this document.
+
+***** Key Generation
+An ~age~ encryption key may be generated like so:
+#+BEGIN_EXAMPLE
+$ umask # Gets current umask
+0022 # Note: This is the default umask for Raspbian 10
+$ umask 066 # So key.txt will have no perms except for owner (you)
+$ umask # Confirm umask set to 066
+0066
+$ age-keygen > key.txt
+Public key: age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5
+$ ls -al key.txt
+-rw------- 1 baltakatei baltakatei 184 Jun 29 18:28 key.txt
+$ umask 0022 # Return umask to default value
+$ umask
+0022
+#+END_EXAMPLE
+
+The resulting public/private keypair data looks like:
+#+BEGIN_EXAMPLE
+$ cat key.txt
+# created: 2020-06-29T18:01:56Z
+# public key: age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5
+AGE-SECRET-KEY-1NEUU5U2XGZGL9UYWNPU5DL99TGJJHFSN4F2E2WCCSDJJ6L5ZMLESNTVTU0
+#+END_EXAMPLE
+
+The file ~key.txt~ is not password-protected by default and should be
+secured like an SSH public key should. The ~$ umask 066~ command run
+before the ~$ age-keygen > key.txt~ command ensures ~key.txt~ will not
+be readable, writeable, or executable to anyone except the owner
+(you).
+
*** Normal Startup
+Turn on Ninfacyzga-01 by supplying 5VDC power to the Raspberry Pi. No
+further interaction should be required.
+*** Normal Operation
+No interaction beyond continually supplying approximately 100mA of
+5VDC power and occasionally removing log files to conserve disk space
+is required.
+**** Log Transfer
+Log files may be transferred by use of ~syncthing~ shared folders.
+**** Automatic Updates
+The ~automatic-upgrades~ package, if installed, should automatically
+install security patches to packages installed via ~apt~.
*** Normal Shutdown
+The system may be shutdown via SSH by running:
+
+: $ sudo shutdown -r 0
+
*** Unscheduled Shutdown
+Ninfacyzga-01 as described and setup should tolerate unscheduled power
+loss. Log files being written every 60 seconds means, at most, 60
+seconds worth of location data may be lost.
*** End of Life Disposal
+LiPo batteries used by the PiZ Uptime 2.0 module should be disposed of
+properly with their potential ignitability in mind, especially if they
+are not fully discharged.
+
+Consult your local municipality for its "E-Waste Disposal" (or
+equivalent) policy. Metals used in the Raspberry Pi and related
+components may be recycled.
+
+Take extra precuation if lead solder was used in assembling the
+electronics. Consumer electronics in early 21st century should use
+lead-free solder.
projects / EVA-2020-02.git / blobdiff