remove(exec/bkplog):Retire old pressure logging script

[EVA-2020-02.git] / TODO.org

* Task List
** TODO Add ~photograph~ (?) logging
The Raspberry Pi Zero W has a camera connector that lets certain types
of camera devices connect. The ~raspistill~ command permits capturing
of photographs and outputting the file to stdout. Therefore, it should
be possible to create a script that periodically calls ~raspistill~ to
output ~jpg~ stdout to ~age~ for encryption and addition to a ~tar~
file. An Arducam IMX219 wide angle camera captures an 8 megapixel
image; default settings of ~raspistill~ produces an image of roughly
~4.5~ to ~5~ megabytes. 

Some commands that can be used for creating timelapses via ~ffmpeg~
are:

: ffmpeg -r 60 -f image2 -s 3280x2464 -pattern_type glob -i '*.jpg' -vcodec libx264 -crf 18 "$(date +%Y%m%dT%H%M%S%z)..time_lapse".mp4
: cat *.jpg | ffmpeg -f image2pipe -i - output.mp4  # see https://trac.ffmpeg.org/wiki/Slideshow#Pipe

*** TODO Augment ~bklog~
Also, either the ~bklog~ script needs to be augmented or a new script
written in order to handle the case of handling an image file coming
in via stdin. Currently, ~bklog~ can't properly handle the stdout
produced by a command such as:

: raspistill -o -

Even if a helper script is written that outputs jpg images via stdout,
~bklog~ currently has no way of knowing how to partition the stream of
stdout into separate files.

Since ~raspistill~ produces a single image and then should be
terminated, it is appropriate to use ~cron~ to call a simple script to
run regularly (ex: every 5 minutes) and to pipe the output to a script
that uses ~age~ to encrypt against a recipient. Code from ~bklog~ can
be reused to do this. It is probably not appropriate to try and
augment ~bklog~ to handle this method of being called since it was
written with the intention of handling continuous streams of stdout.

* Finished Tasks
** DONE Remove unused executables
   CLOSED: [2021-01-25 Mon 00:07]
Date Created: 2021-01-25T00:03Z

Some unused executables are present in the ~exec/~ directory that are
not used. An example is ~bkgpslog~ which has been superceded by
~gpspipe | bklog~.

** DONE ~/doc/time~: Migrate from ~ntpsec~ to ~chrony~
   CLOSED: [2020-10-19 Mon 03:48]
The ~ntpsec~ package is in the ~dfsg~ Debian repository instead of the
~main~ Debian repository. This is likely due to ~ntpsec~ using a mix
of ~ntp~'s original "NTP License", ~BSD 2~, and ~MIT~ licenses.

In contrast, ~chrony~ uses the ~GPLv2~ license which allows it to be
in the Debian main repository.

~gpsd~ documentation for communicating to ~chrony~ via
~/run/chrony.XXXX.sock~ and ~/run/chrony.YYYY.sock~ sockets (for GPS
and PPS data respectively) can be found [[https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html#_feeding_chrony_from_gpsd][here]].

*** Closing comments (bktei):
~chrony~ seems much simpler to configure. Its method for interfacing
with ~gpsd~ seems simpler as well. The fact that it displays time
units in its ~chronyc sources~ output means the developers value
communicating clearly the values they provide the user.
** DONE ~doc/setup~: Disable bluetooth
   CLOSED: [2020-10-19 Mon 03:50]
*** Closing comments (bktei):
Bluetooth is disabled via a ~systemctl~ command and modifications to
~/boot/config.txt~.