| 1 | * Location Logging |
| 2 | This document was created by Steven Baltakatei Sandoval on |
| 3 | <2020-06-29 Mon 12:14> under a [[https://creativecommons.org/licenses/by-sa/4.0/][Creative Commons BY-SA 4.0 license]]. It |
| 4 | was updated by Steven Baltakatei Sandoval on <2020-06-29 Mon 16:05>. |
| 5 | ** Narrative |
| 6 | Ninfacyzga-01 records (logs) its position in time and space using a |
| 7 | [[https://en.wikipedia.org/wiki/Satellite_navigation_device][GPS receiver]]. The NMEA location data produced by the receiver is |
| 8 | converted into the more commonly used GPS data storage formats of GPX |
| 9 | and KML. All three types of data are then compressed and encrypted |
| 10 | against a set of public keys. The encrypted data is then written to |
| 11 | disk. Data produced by the receiver is segmented into 60-second chunks |
| 12 | before being processed and written to disk. |
| 13 | ** Description |
| 14 | *** Hardware |
| 15 | **** Raspberry Pi Zero W |
| 16 | See the [[https://www.raspberrypi.org/pi-zero-w/][OEM]] webpage for this product. |
| 17 | **** PiZ UpTime 2.0 |
| 18 | See the [[https://alchemy-power.com/piz-uptime-2-0/][OEM]] webpage for this product. |
| 19 | *** Software |
| 20 | ~bkgpslog~ : The bash script that performs the location data |
| 21 | collection and processing. Is an executable file contained within this |
| 22 | repository at ~exec/bkgpslog~. It should be copied to |
| 23 | ~$HOME/.local/bin~. |
| 24 | |
| 25 | ~gpsd~ : A background daemon app capable of interfacing with the |
| 26 | Ozzmaker BerryGPS-IMU's GPS submodule. Installed and initialized by |
| 27 | ~apt~. |
| 28 | |
| 29 | ~gpspipe~ : A command line app that polls ~gpsd~ and produces a stream |
| 30 | stdout consisting of GPS data lines in NMEA format. Installed via |
| 31 | ~apt~. |
| 32 | |
| 33 | ~gpsbabel~ : A command line app that converts GPS data from one format |
| 34 | into another. ~bkgpslog~ uses it to convert NMEA data into GPX and |
| 35 | KML. Installed via ~apt~. |
| 36 | |
| 37 | ~gzip~ : A simple command line app that compresses stdin into a |
| 38 | smaller stdout stream. |
| 39 | |
| 40 | ~age~ : A simple command line app that encrypts stdin against public |
| 41 | keys specified in its options. Produces encrypted stdout. Is an |
| 42 | executable file contained within this repository at ~exec/age~. It |
| 43 | should be copied to ~$HOME/.local/bin~. |
| 44 | |
| 45 | **** Narrative |
| 46 | ~bkgpslog~ populates a 60-second buffer with NMEA data from ~gpsd~ via |
| 47 | ~gpspipe~. This buffer is used by ~gpsbabel~ to produce GPX and KML |
| 48 | versions of the buffer. All 3 buffers are then comprssed with ~gzip~, |
| 49 | encrypted with ~age~, and then written to disk. |
| 50 | |
| 51 | *** Output |
| 52 | **** File Formats |
| 53 | ***** NMEA |
| 54 | See the [[https://en.wikipedia.org/wiki/NMEA_0183][Wikipedia page]] for this. |
| 55 | ***** GPX |
| 56 | See the [[https://en.wikipedia.org/wiki/GPS_Exchange_Format][Wikipedia page]] for this. |
| 57 | ***** KML |
| 58 | See the [[https://en.wikipedia.org/wiki/Keyhole_Markup_Language][Wikipedia page]] for this. |
| 59 | **** Encryption Method |
| 60 | Files produced by the bkgpslog script are encrypted against a set of |
| 61 | public keys using [[https://github.com/FiloSottile/age][age]]. The public keys are bech32 strings supplied as |
| 62 | options to bkgpslog when called. |
| 63 | ** Operating Procedures |
| 64 | *** Initial Startup |
| 65 | *** Normal Startup |
| 66 | *** Normal Shutdown |
| 67 | *** Unscheduled Shutdown |
| 68 | *** End of Life Disposal |
| 69 | |