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        <channel>
                <title>Petter Reinholdtsen</title>
                <description></description>
                <link>https://people.skolelinux.org/pere/blog/</link>
                <atom:link href="https://people.skolelinux.org/pere/blog/index.rss" rel="self" type="application/rss+xml" />
        
        <item>
                <title>Automatic LinuxCNC servo PID tuning?</title>
                <link>https://people.skolelinux.org/pere/blog/Automatic_LinuxCNC_servo_PID_tuning_.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/Automatic_LinuxCNC_servo_PID_tuning_.html</guid>
                <pubDate>Sat, 16 Jul 2022 22:30:00 +0200</pubDate>
                <description>&lt;p&gt;While working on a CNC with servo motors controlled by the
&lt;a href=&quot;https://en.wikipedia.org/wiki/LinuxCNC&quot;&gt;LinuxCNC&lt;/a&gt;
&lt;a href=&quot;https://en.wikipedia.org/wiki/PID_controller&quot;&gt;PID
controller&lt;/a&gt;, I recently had to learn how to tune the collection of values
that control such mathematical machinery that a PID controller is.  It
proved to be a lot harder than I hoped, and I still have not succeeded
in getting the Z PID controller to successfully defy gravity, nor X
and Y to move accurately and reliably.  But while climbing up this
rather steep learning curve, I discovered that some motor control
systems are able to tune their PID controllers.  I got the impression
from the documentation that LinuxCNC were not.  This proved to be not
true&lt;/p&gt;

&lt;p&gt;The LinuxCNC
&lt;a href=&quot;http://linuxcnc.org/docs/html/man/man9/pid.9.html&quot;&gt;pid
component&lt;/a&gt; is the recommended PID controller to use.  It uses eight
constants &lt;tt&gt;Pgain&lt;/tt&gt;, &lt;tt&gt;Igain&lt;/tt&gt;, &lt;tt&gt;Dgain&lt;/tt&gt;,
&lt;tt&gt;bias&lt;/tt&gt;, &lt;tt&gt;FF0&lt;/tt&gt;, &lt;tt&gt;FF1&lt;/tt&gt;, &lt;tt&gt;FF2&lt;/tt&gt; and
&lt;tt&gt;FF3&lt;/tt&gt; to calculate the output value based on current and wanted
state, and all of these need to have a sensible value for the
controller to behave properly.  Note, there are even more values
involved, theser are just the most important ones.  In my case I need
the X, Y and Z axes to follow the requested path with little error.
This has proved quite a challenge for someone who have never tuned a
PID controller before, but there is at least some help to be found.

&lt;p&gt;I discovered that included in LinuxCNC was this old PID component
at_pid claiming to have auto tuning capabilities.  Sadly it had been
neglected since 2011, and could not be used as a plug in replacement
for the default pid component.  One would have to rewriting the
LinuxCNC HAL setup to test at_pid.  This was rather sad, when I wanted
to quickly test auto tuning to see if it did a better job than me at
figuring out good P, I and D values to use.&lt;/p&gt;

&lt;p&gt;I decided to have a look if the situation could be improved.  This
involved trying to understand the code and history of the pid and
at_pid components.  Apparently they had a common ancestor, as code
structure, comments and variable names were quite close to each other.
Sadly this was not reflected in the git history, making it hard to
figure out what really happened.  My guess is that the author of
&lt;a href=&quot;https://github.com/LinuxCNC/linuxcnc/blob/master/src/hal/components/at_pid.c&quot;&gt;at_pid.c&lt;/a&gt;
took a version of
&lt;a href=&quot;https://github.com/LinuxCNC/linuxcnc/blob/master/src/hal/components/pid.c&quot;&gt;pid.c&lt;/a&gt;,
rewrote it to follow the structure he wished pid.c to have, then added
support for auto tuning and finally got it included into the LinuxCNC
repository.  The restructuring and lack of early history made it
harder to figure out which part of the code were relevant to the auto
tuning, and which part of the code needed to be updated to work the
same way as the current pid.c implementation.  I started by trying to
isolate relevant changes in pid.c, and applying them to at_pid.c.  My
aim was to make sure the at_pid component could replace the pid
component with a simple change in the HAL setup loadrt line, without
having to &quot;rewire&quot; the rest of the HAL configuration.  After a few
hours following this approach, I had learned quite a lot about the
code structure of both components, while concluding I was heading down
the wrong rabbit hole, and should get back to the surface and find a
different path.&lt;/p&gt;

&lt;p&gt;For the second attempt, I decided to throw away all the PID control
related part of the original at_pid.c, and instead isolate and lift
the auto tuning part of the code and inject it into a copy of pid.c.
This ensured compatibility with the current pid component, while
adding auto tuning as a run time option.  To make it easier to identify
the relevant parts in the future, I wrapped all the auto tuning code
with &#39;#ifdef AUTO_TUNER&#39;.  The end result behave just like the current
pid component by default, as that part of the code is identical.  The
&lt;a href=&quot;https://github.com/LinuxCNC/linuxcnc/pull/1820&quot;&gt;end result
entered the LinuxCNC master branch&lt;/a&gt; a few days ago.&lt;/p&gt;

&lt;p&gt;To enable auto tuning, one need to set a few HAL pins in the PID
component.  The most important ones are &lt;tt&gt;tune-effort&lt;/tt&gt;,
&lt;tt&gt;tune-mode&lt;/tt&gt; and &lt;tt&gt;tune-start&lt;/tt&gt;.  But lets take a step
back, and see what the auto tuning code will do.  I do not know the
mathematical foundation of the at_pid algorithm, but from observation
I can tell that the algorithm will, when enabled, produce a square
wave pattern centered around the &lt;tt&gt;bias&lt;/tt&gt; value on the output pin
of the PID controller.  This can be seen using the HAL Scope provided
by LinuxCNC.  In my case, this is translated into voltage (+-10V) sent
to the motor controller, which in turn is translated into motor speed.
So at_pid will ask the motor to move the axis back and forth.  The
number of cycles in the pattern is controlled by the
&lt;tt&gt;tune-cycles&lt;/tt&gt; pin, and the extremes of the wave pattern is
controlled by the &lt;tt&gt;tune-effort&lt;/tt&gt; pin.  Of course, trying to
change the direction of a physical object instantly (as in going
directly from a positive voltage to the equivalent negative voltage)
do not change velocity instantly, and it take some time for the object
to slow down and move in the opposite direction.  This result in a
more smooth movement wave form, as the axis in question were vibrating
back and forth.  When the axis reached the target speed in the
opposing direction, the auto tuner change direction again.  After
several of these changes, the average time delay between the &#39;peaks&#39;
and &#39;valleys&#39; of this movement graph is then used to calculate
proposed values for Pgain, Igain and Dgain, and insert them into the
HAL model to use by the pid controller.  The auto tuned settings are
not great, but htye work a lot better than the values I had been able
to cook up on my own, at least for the horizontal X and Y axis.  But I
had to use very small &lt;tt&gt;tune-effort&lt;tt&gt; values, as my motor
controllers error out if the voltage change too quickly.  I&#39;ve been
less lucky with the Z axis, which is moving a heavy object up and
down, and seem to confuse the algorithm.  The Z axis movement became a
lot better when I introduced a &lt;tt&gt;bias&lt;/tt&gt; value to counter the
gravitational drag, but I will have to work a lot more on the Z axis
PID values.&lt;/p&gt;

&lt;p&gt;Armed with this knowledge, it is time to look at how to do the
tuning.  Lets say the HAL configuration in question load the PID
component for X, Y and Z like this:&lt;/p&gt;
 
&lt;blockquote&gt;&lt;pre&gt;
loadrt pid names=pid.x,pid.y,pid.z
&lt;/pre&gt;&lt;/blockquote&gt;

&lt;p&gt;Armed with the new and improved at_pid component, the new line will
look like this:&lt;/p&gt;

&lt;blockquote&gt;&lt;pre&gt;
loadrt at_pid names=pid.x,pid.y,pid.z
&lt;/pre&gt;&lt;/blockquote&gt;

&lt;p&gt;The rest of the HAL setup can stay the same.  This work because the
components are referenced by name.  If the component had used count=3
instead, all use of pid.# had to be changed to at_pid.#.&lt;/p&gt;

&lt;p&gt;To start tuning the X axis, move the axis to the middle of its
range, to make sure it do not hit anything when it start moving back
and forth.  Next, set the &lt;tt&gt;tune-effort&lt;/tt&gt; to a low number in the
output range.  I used 0.1 as my initial value.  Next, assign 1 to the
&lt;tt&gt;tune-mode&lt;/tt&gt; value. Note, this will disable the pid controlling
part and feed 0 to the output pin, which in my case initially caused a
lot of drift.  In my case it proved to be a good idea with X and Y to
tune the motor driver to make sure 0 voltage stopped the motor
rotation.  On the other hand, for the Z axis this proved to be a bad
idea, so it will depend on your setup.  It might help to set the
&lt;tt&gt;bias&lt;/tt&gt; value to a output value that reduce or eliminate the
axis drift.  Finally, after setting &lt;tt&gt;tune-mode&lt;/tt&gt;, set
&lt;tt&gt;tune-start&lt;/tt&gt; to 1 to activate the auto tuning.  If all go well,
your axis will vibrate for a few seconds and when it is done, new
values for Pgain, Igain and Dgain will be active.  To test them,
change &lt;tt&gt;tune-mode&lt;/tt&gt; back to 0.  Note that this might cause the
machine to suddenly jerk as it bring the axis back to its commanded
position, which it might have drifted away from during tuning.  To
summarize with some halcmd lines:&lt;/p&gt;

&lt;blockquote&gt;&lt;pre&gt;
setp pid.x.tune-effort 0.1
setp pid.x.tune-mode 1
setp pid.x.tune-start 1
# wait for the tuning to complete
setp pid.x.tune-mode 0
&lt;/pre&gt;&lt;/blockquote&gt;

&lt;p&gt;After doing this task quite a few times while trying to figure out
how to properly tune the PID controllers on the machine in, I decided
to figure out if this process could be automated, and wrote a script
to do the entire tuning process from power on.  The end result will
ensure the machine is powered on and ready to run, home all axis if it
is not already done, check that the extra tuning pins are available,
move the axis to its mid point, run the auto tuning and re-enable the
pid controller when it is done.  It can be run several times.  Check
out the
&lt;a href=&quot;https://github.com/SebKuzminsky/MazakVQC1540/blob/bon-dev/scripts/run-auto-pid-tuner&quot;&gt;run-auto-pid-tuner&lt;/a&gt;
script on github if you want to learn how it is done.&lt;/p&gt;

&lt;p&gt;My hope is that this little adventure can inspire someone who know
more about motor PID controller tuning can implement even better
algorithms for automatic PID tuning in LinuxCNC, making life easier
for both me and all the others that want to use LinuxCNC but lack the
in depth knowledge needed to tune PID controllers well.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
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        <item>
                <title>My free software activity of late (2022)</title>
                <link>https://people.skolelinux.org/pere/blog/My_free_software_activity_of_late__2022_.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/My_free_software_activity_of_late__2022_.html</guid>
                <pubDate>Mon, 20 Jun 2022 14:30:00 +0200</pubDate>
                <description>&lt;p&gt;I guess it is time to bring some light on the various free software
and open culture activities and projects I have worked on or been
involved in the last year and a half.&lt;/p&gt;

&lt;p&gt;First, lets mention the book
&lt;a href=&quot;http://www.hungry.com/~pere/publisher/&quot;&gt;releases I managed to
publish&lt;/a&gt;.  The Cory Doctorow book &quot;Hvordan knuse
overvåkningskapitalismen&quot; argue that it is not the magic machine
learning of the big technology companies that causes the surveillance
capitalism to thrive, it is the lack of trust busting to enforce
existing anti-monopoly laws.  I also published a family of
dictionaries for machinists, one sorted on the English words, one
sorted on the Norwegian and the last sorted on the North Sámi words.
A bit on the back burner but not forgotten is the Debian
Administrators Handbook, where a new edition is being worked on.  I
have not spent as much time as I want to help bring it to completion,
but hope I will get more spare time to look at it before the end of
the year.&lt;/p&gt;

&lt;p&gt;With my Debian had I have spent time on several projects, both
updating existing packages, helping to bring in new packages and
working with upstream projects to try to get them ready to go into
Debian.  The list is rather long, and I will only mention my own
isenkram, openmotor, vlc bittorrent plugin, xprintidle, norwegian
letter style for latex, bs1770gain, and recordmydesktop.  In addition
to these I have sponsored several packages into Debian, like audmes.&lt;/p&gt;

&lt;p&gt;The last year I have looked at several infrastructure projects for
collecting meter data and video surveillance recordings.  This include
several ONVIF related tools like onvifviewer and zoneminder as well as
rtl-433, wmbusmeters and rtl-wmbus.&lt;/p&gt;

&lt;p&gt;In parallel with this I have looked at fabrication related free
software solutions like pycam and LinuxCNC.  The latter recently
gained improved translation support using po4a and weblate, which was
a harder nut to crack that I had anticipated when I started.&lt;/p&gt;

&lt;p&gt;Several hours have been spent translating free software to
Norwegian Bokmål on the Weblate hosted service.  Do not have a
complete list, but you will find my contributions in at least gnucash,
minetest and po4a.&lt;/p&gt;

&lt;p&gt;I also spent quite some time on the Norwegian archiving specification
Noark 5, and its companion project Nikita implementing the API
specification for Noark 5.&lt;/p&gt;

&lt;p&gt;Recently I have been looking into free software tools to do company
accounting here in Norway., which present an interesting mix between
law, rules, regulations, format specifications and API interfaces.&lt;/p&gt;

&lt;p&gt;I guess I should also mention the Norwegian community driven
government interfacing projects Mimes Brønn and Fiksgatami, which have
ended up in a kind of limbo while the future of the projects is being
worked out.&lt;/p&gt;

&lt;p&gt;These are just a few of the projects I have been involved it, and
would like to give more visibility.  I&#39;ll stop here to avoid delaying
this post.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>LinuxCNC translators life just got a bit easier</title>
                <link>https://people.skolelinux.org/pere/blog/LinuxCNC_translators_life_just_got_a_bit_easier.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/LinuxCNC_translators_life_just_got_a_bit_easier.html</guid>
                <pubDate>Fri, 3 Jun 2022 21:10:00 +0200</pubDate>
                <description>&lt;p&gt;Back in oktober last year, when I started looking at the
&lt;a href=&quot;https://en.wikipedia.org/wiki/LinuxCNC&quot;&gt;LinuxCNC&lt;/a&gt; system, I
proposed to change the documentation build system make life easier for
translators.  The original system consisted of independently written
documentation files for each language, with no automated way to track
changes done in other translations and no help for the translators to
know how much was left to translated.  By using
&lt;a href=&quot;https://po4a.org/&quot;&gt;the po4a system&lt;/a&gt; to generate POT and PO
files from the English documentation, this can be improved.  A small
team of LinuxCNC contributors got together and today our labour
finally payed off.  Since a few hours ago, it is now possible to
translate &lt;a href=&quot;https://hosted.weblate.org/projects/linuxcnc/&quot;&gt;the
LinuxCNC documentation on Weblate&lt;/a&gt;, alongside the program itself.&lt;/p&gt;

&lt;p&gt;The effort to migrate the documentation to use po4a has been both
slow and frustrating.  I am very happy we finally made it.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>geteltorito make CD firmware upgrades a breeze</title>
                <link>https://people.skolelinux.org/pere/blog/geteltorito_make_CD_firmware_upgrades_a_breeze.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/geteltorito_make_CD_firmware_upgrades_a_breeze.html</guid>
                <pubDate>Wed, 20 Apr 2022 11:50:00 +0200</pubDate>
                <description>&lt;p&gt;Recently I wanted to upgrade the firmware of my thinkpad, and
located the firmware download page from Lenovo (which annoyingly do
not allow access via Tor, forcing me to hand them more personal
information that I would like).  The
&lt;a href=&quot;https://support.lenovo.com/no/en/search?query=thinkpad firmware bios upgrade iso&amp;SearchType=Customer search&amp;searchLocation=Masthead&quot;&gt;download
from Lenovo&lt;/a&gt; is a bootable ISO image, which is a bit of a problem
when all I got available is a USB memory stick.  I tried booting the
ISO as a USB stick, but this did not work.  But genisoimage came to
the rescue.&lt;/p&gt;

&lt;P&gt;The geteltorito program in
&lt;a href=&quot;http://tracker.debian.org/cdrkit&quot;&gt;the genisoimage binary
package&lt;/a&gt; is able to convert the bootable ISO image to a bootable
USB stick using a simple command line recipe, which I then can write
to the most recently inserted USB stick:&lt;/p&gt;

&lt;blockquote&gt;&lt;pre&gt;
geteltorito -o usbstick.img lenovo-firmware.iso
sudo dd bs=10M if=usbstick.img of=$(ls -tr /dev/sd?|tail -1)
&lt;/pre&gt;&lt;/blockquote&gt;

&lt;p&gt;This USB stick booted the firmware upgrader just fine, and in a few
minutes my machine had the latest and greatest BIOS firmware in place.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Playing and encoding AV1 in Debian Bullseye</title>
                <link>https://people.skolelinux.org/pere/blog/Playing_and_encoding_AV1_in_Debian_Bullseye.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/Playing_and_encoding_AV1_in_Debian_Bullseye.html</guid>
                <pubDate>Sat, 16 Apr 2022 08:40:00 +0200</pubDate>
                <description>&lt;p&gt;Inspired by the recent news of
&lt;a href=&quot;https://slashdot.org/story/22/04/03/2039219/intel-beats-amd-and-nvidia-with-arc-gpus-full-av1-support&quot;&gt;AV1
hardware encoding support from Intel&lt;/a&gt;, I decided to look into
the state of AV1 on Linux today.  AV1 is a
&lt;a href=&quot;https://web.archive.org/web/20160618103850/http://www.digistan.org/open-standard:definition&quot;&gt;free
and open standard&lt;/a&gt; as defined by Digistan without any royalty
payment requirement, unlike its much used competitor encoding
H.264.  While looking, I came across an 5 year
&lt;a href=&quot;https://askubuntu.com/questions/1061908/how-to-encode-and-playback-video-with-the-av1-codec-on-bionic-beaver-18-04&quot;&gt;old
question on askubuntu.com&lt;/a&gt; which in turn inspired me to check out
how things are in Debian Stable regarding AV1.  The test file listed
in the question (askubuntu_test_aom.mp4) did not exist any more, so I
tracked down a different set of test files on
&lt;a href=&quot;https://av1.webmfiles.org/&quot;&gt;av1.webmfiles.org&lt;/a&gt; to test them
with the various video tools I had installed on my machine.  I was
happy to discover that AV1 decoding and playback worked with almost
every tool I tested:

&lt;table align=&quot;center&quot;&gt;
&lt;tr&gt;&lt;td&gt;mediainfo&lt;/td&gt;       &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;dragonplayer&lt;/td&gt;    &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;ffmpeg / ffplay&lt;/td&gt; &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;gnome-mplayer&lt;/td&gt;   &lt;td&gt;fail&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;mplayer&lt;/td&gt;       &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;mpv&lt;/td&gt;           &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;parole&lt;/td&gt;        &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;vlc&lt;/td&gt;           &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;firefox&lt;/td&gt;         &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td&gt;chromium&lt;/td&gt;        &lt;td&gt;ok&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;

&lt;p&gt;AV1 encoding is available in Debian Stable from the aom-tools
version 1.0.0.errata1-3 package, using the aomenc tool.  The encoding
using the package in Debian Stable is quite slow, with the frame rate
for my 10 second test video at around 0.25 fps.  My 10 second video
test took 16 minutes and 11 seconds on my test machine.&lt;/p&gt;

&lt;p&gt;I tested by first running ffmpeg and then aomenc using the recipe
provided by the askubuntu recipe above.  I had to remove the
&#39;--row-mt=1&#39; option, as it was not supported in my 1.0.0 version.  The
encoding only used a single thread, according to &lt;tt&gt;top&lt;/tt&gt;.&lt;/p&gt;

&lt;blockquote&gt;&lt;pre&gt;
ffmpeg -i some-old-video.ogv -t 10 -pix_fmt yuv420p video.y4m
aomenc --fps=24/1 -u 0 --codec=av1 --target-bitrate=1000 \
  --lag-in-frames=25 --auto-alt-ref=1 -t 24 --cpu-used=8 \
  --tile-columns=2 --tile-rows=2 -o output.webm video.y4m
&lt;/pre&gt;&lt;/blockquote&gt;

&lt;p&gt;As version 1.0.0 currently have several
&lt;a href=&quot;https://security-tracker.debian.org/tracker/source-package/aom&quot;&gt;unsolved
security issues in Debian Stable&lt;/a&gt;, and to see if the recent
backport &lt;a href=&quot;https://tracker.debian.org/pkg/aom&quot;&gt;provided in
Debian&lt;/a&gt; is any quicker, I ran &lt;tt&gt;apt -t bullseye-backports install
aom-tools&lt;/tt&gt; to fetch the backported version and re-encoded the
video using the latest version.  This time the &#39;--row-mt=1&#39; option
worked, and the encoding was done in 46 seconds with a frame rate of
around 5.22 fps.  This time it seem to be using all my four cores to
encode.  Encoding speed is still too low for streaming and real time,
which would require frame rates above 25 fps, but might be good enough
for offline encoding.&lt;/p&gt;

&lt;p&gt;I am very happy to see AV1 playback working so well with the
default tools in Debian Stable.  I hope the encoding situation improve
too, allowing even a slow old computer like my 10 year old laptop to
be used for encoding.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Få en slutt på Digitale utslipp</title>
                <link>https://people.skolelinux.org/pere/blog/F__en_slutt_p__Digitale_utslipp.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/F__en_slutt_p__Digitale_utslipp.html</guid>
                <pubDate>Mon, 14 Mar 2022 22:00:00 +0100</pubDate>
                <description>&lt;p&gt;På onsdag sendte jeg følgende epost til Utdanningsetaten i Oslo
kommune (UDE).  Fikk beskjed om at min henvendelse har saksnummer
22/7559-1 i den
&lt;a href=&quot;https://www.oslo.kommune.no/etater-foretak-og-ombud/utdanningsetaten/postjournal-utdanningsetaten/&quot;&gt;offentlige
postjournalen til UDE&lt;/a&gt;.  Jeg er spent på hva slags respons jeg får.
Mistenker jo de fleste som sprer sine nettsideleseres
personopplysninger til utlandet ikke har tenkt så nøye igjennom hva de
gjør, og at det er håp om at de tenker seg litt nøyere om hvis de blir
klar over problemstillingen.  Vet du noen som burde få tilsvarede
beskjed og spørsmål?  Kanskje du kan sende dem en epost.  Hvis alle
bidrar blir det kanskje litt bedre.&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;To: postmottak (at) osloskolen.no
&lt;br&gt;Subject: Digitale utslipp fra osloskolens nettsider&lt;/p&gt;

&lt;p&gt;Hei.&lt;/p&gt;

&lt;p&gt;Jeg ser at osloskolens nettsider har digitale utslipp av
personopplysninger til Google, Facebook og andre, blant annet omtalt
på &amp;lt;URL: &lt;a href=&quot;https://aktuelt.osloskolen.no/personvernerklaring-for-osloskolen/informasjonskapsler/&quot;&gt;https://aktuelt.osloskolen.no/personvernerklaring-for-osloskolen/informasjonskapsler/&lt;/a&gt;
&gt;.&lt;/p&gt;

&lt;p&gt;&amp;lt;URL: &lt;a href=&quot;https://webbkoll.dataskydd.net/&quot;&gt;https://webbkoll.dataskydd.net/&lt;/a&gt; &gt; kan være et nyttig verktøy for å holde øye med utslippsomfanget på ulike sider.&lt;/p&gt;

&lt;p&gt;Kanskje det er en ide å gjøre noe med det, jamfør &amp;lt;URL: &lt;a href=&quot;https://www.digi.no/artikler/debatt-det-enkleste-tiltaket-er-a-skru-av-google-analytics/517378&quot;&gt;https://www.digi.no/artikler/debatt-det-enkleste-tiltaket-er-a-skru-av-google-analytics/517378&lt;/a&gt; &gt;?&lt;/p&gt;

&lt;p&gt;Et alternativ til Google Analytics kan være en lokalt installert
utgave av &amp;lt;URL:
&lt;a href=&quot;https://matomo.org/&quot;&gt;https://matomo.org/&lt;/a&gt; &gt;.  Den og flere
andre alternativer kan finnes via
&amp;lt;URL: &lt;a href=&quot;https://www.digi.no/artikler/sverige-vil-skrote-amerikansk-skytjeneste-her-er-alternativene/516223?key=5QsV0wRG&quot;&gt;https://www.digi.no/artikler/sverige-vil-skrote-amerikansk-skytjeneste-her-er-alternativene/516223?key=5QsV0wRG&lt;/a&gt; &gt;
på bakgrunn av at svenske myndigheter har innsett at dagens praksis
nok er både lite lur og ulovlig.  Der henger Norge litt etter, men
osloskolen har her mulighet til å være litt i forkant. :)&lt;/p&gt;

&lt;p&gt;Fint om dere kan gi beskjed hvilket saksnummer denne henvendelsen får i
offentlig postjournal når den er mottatt.&lt;/p&gt;

&lt;/blockquote&gt;

&lt;/p&gt;Flere og flere innser at slik spredning av personopplysninger er
ugreit.  Det har pågått i mange år.  Ser jeg blogget
&lt;a href=&quot;https://people.skolelinux.org/pere/blog/Det_er_jo_makta_som_er_mest_s_rbar_ved_massiv_overv_kning_av_Internett.html&quot;&gt;første
gang om Google Analytics i 2013&lt;/a&gt; og
&lt;a href=&quot;https://people.skolelinux.org/pere/blog/Snurpenot_overv_kning_av_sensitiv_personinformasjon.html&quot;&gt;analyserte
omfanget i 2015&lt;/a&gt;, men det er et langt lerret å bleke.&lt;/p&gt;

&lt;p&gt;Som vanlig, hvis du bruker Bitcoin og ønsker å vise din støtte til
det jeg driver med, setter jeg pris på om du sender Bitcoin-donasjoner
til min adresse
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.
Merk, betaling med bitcoin er ikke anonymt. :)&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Publish Hargassner wood chip boiler state to MQTT</title>
                <link>https://people.skolelinux.org/pere/blog/Publish_Hargassner_wood_chip_boiler_state_to_MQTT.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/Publish_Hargassner_wood_chip_boiler_state_to_MQTT.html</guid>
                <pubDate>Sat, 12 Mar 2022 06:30:00 +0100</pubDate>
                <description>&lt;p&gt;Recently I had a look at a
&lt;a href=&quot;https://www.hargassner.at/&quot;&gt;Hargassner&lt;/a&gt;
&lt;a href=&quot;https://www.hargassner.at/en/products/wood-chip-boiler.html&quot;&gt;wood
chip boiler&lt;/a&gt;, and what kind of free software can be used to monitor
and control it.  The boiler can be connected to some cloud service via
what the producer call an Internet Gateway, which seem to be a
computer connecting to the boiler and passing the information gathered
to the cloud.  I discovered the boiler controller got an IP address on
the local network and listen on TCP port 23 to provide status
information as a text line of numbers.  It also provide a HTTP server
listening on port 80, but I have not yet figured out what it can do
beside return an error code.&lt;/p&gt;

&lt;p&gt;If I am to believe various free software implementations talking to
such boiler, the interpretation of the line of numbers differ between
type of boiler and software version on the boiler.  By comparing the
list of numbers on the front panel of the boiler with the numbers
returned via TCP, I have been able to figure out several of the
numbers, but there are a lot left to understand.  I&#39;ve located several
temperature measurements and hours running values, as well as oxygen
measurements and counters.&lt;/p&gt;

I decided to write a simple parser in Python for the values I figured
out so far, and a simple MQTT injector publishing both the interpreted
and the unknown values on a MQTT bus to make collecting and graphing
simpler.  The end result is available from the
&lt;a href=&quot;https://gitlab.com/petterreinholdtsen/hargassner2mqtt&quot;&gt;hargassner2mqtt
project page&lt;/a&gt; on gitlab.  I very much welcome patches extending the
parser to understand more values, boiler types and software versions.
I do not really expect very few free software developers got their
hands on such unit to experiment, but it would be fun if others too find
this project useful.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Run your industrial metal working machine using Debian?</title>
                <link>https://people.skolelinux.org/pere/blog/Run_your_industrial_metal_working_machine_using_Debian_.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/Run_your_industrial_metal_working_machine_using_Debian_.html</guid>
                <pubDate>Wed, 2 Mar 2022 18:40:00 +0100</pubDate>
                <description>&lt;p&gt;After many months of hard work by the good people involved in
&lt;a href=&quot;https://en.wikipedia.org/wiki/LinuxCNC&quot;&gt;LinuxCNC&lt;/a&gt;, the
system was accepted Sunday
&lt;a href=&quot;https://tracker.debian.org/pkg/linuxcnc&quot;&gt;into Debian&lt;/a&gt;.
Once it was available from Debian, I was surprised to discover from
&lt;a href=&quot;https://qa.debian.org/popcon.php?package=linuxcnc&quot;&gt;its
popularity-contest numbers&lt;/a&gt; that people have been reporting its use
since 2012.  &lt;a href=&quot;http://linuxcnc.org/&quot;&gt;Its project site&lt;/a&gt; might
be a good place to check out, but sadly is not working when visiting
via Tor.&lt;/p&gt;

&lt;p&gt;But what is LinuxCNC, you are probably wondering?  Perhaps a
Wikipedia quote is in place?&lt;/p&gt;

&lt;blockquote&gt;
&quot;LinuxCNC is a software system for numerical control of
machines such as milling machines, lathes, plasma cutters, routers,
cutting machines, robots and hexapods. It can control up to 9 axes or
joints of a CNC machine using G-code (RS-274NGC) as input. It has
several GUIs suited to specific kinds of usage (touch screen,
interactive development).&quot;
&lt;/blockquote&gt;

&lt;p&gt;It can even control 3D printers.  And even though the Wikipedia
page indicate that it can only work with hard real time kernel
features, it can also work with the user space soft real time features
provided by the Debian kernel.
&lt;a href=&quot;https://github.com/linuxcnc/linuxcnc&quot;&gt;The source code&lt;/a&gt; is
available from Github.  The last few months I&#39;ve been involved in the
translation setup for the program and documentation.  Translators are
most welcome to
&lt;a href=&quot;https://hosted.weblate.org/engage/linuxcnc/&quot;&gt;join the
effort&lt;/a&gt; using Weblate.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Updated vlc bittorrent plugin in Debian (version 2.14)</title>
                <link>https://people.skolelinux.org/pere/blog/Updated_vlc_bittorrent_plugin_in_Debian__version_2_14_.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/Updated_vlc_bittorrent_plugin_in_Debian__version_2_14_.html</guid>
                <pubDate>Mon, 14 Feb 2022 08:00:00 +0100</pubDate>
                <description>&lt;p&gt;I am very happy to report that a new version of the
&lt;a href=&quot;https://tracker.debian.org/pkg/vlc-plugin-bittorrent&quot;&gt;VLC
bittorrent plugin&lt;/a&gt; was just uploaded into debian.  The changes
since last time is mostly code clean in the download code. The package
is currently in Debian unstable, but should be available in Debian
testing son.  To test it, simply install it like this:&lt;/p&gt;

&lt;p&gt;&lt;pre&gt;
apt install vlc-plugin-bittorrent
&lt;/pre&gt;&lt;/p&gt;

&lt;p&gt;After it is installed, you can try to use it to play a file
downloaded live via bittorrent like this:

&lt;p&gt;&lt;pre&gt;
vlc https://archive.org/download/Glass_201703/Glass_201703_archive.torrent
&lt;/pre&gt;&lt;/p&gt;

&lt;p&gt;It can also use magnet links and local .torrent files like the ones
provided by the Internet Archive.  Another example is the &lt;a
href=&quot;https://archive.org/details/LoveNest&quot;&gt;Love Nest&lt;/a&gt; Buster
Keaton movie, where one can click on the &#39;Torrent&#39; link to get going.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>A Brazilian Portuguese translation of the book Made with Creative Commons</title>
                <link>https://people.skolelinux.org/pere/blog/A_Brazilian_Portuguese_translation_of_the_book_Made_with_Creative_Commons.html</link>
                <guid isPermaLink="true">https://people.skolelinux.org/pere/blog/A_Brazilian_Portuguese_translation_of_the_book_Made_with_Creative_Commons.html</guid>
                <pubDate>Fri, 3 Dec 2021 09:30:00 +0100</pubDate>
                <description>&lt;p&gt;A few days ago, a productive translator started working on a new
translation of &lt;a href=&quot;https://madewith.cc&quot;&gt;the Made with Creative
Commons book&lt;/a&gt; for Brazilian Portuguese.  The translation take place on
&lt;a href=&quot;https://hosted.weblate.org/projects/madewithcc/translation/&quot;&gt;the
Weblate web based translation system&lt;/a&gt;.  Once the translation is
complete and proof read, we can publish it on paper as well as in PDF,
ePub and HTML format.  The translation is already 16% complete, and if
more people get involved I am conviced it can very quickly reach 100%.
If you are interested in helping out with this or other translations
of the Made with Creative Commons book, start translating on
Weblate.  There are partial translations available in Azerbaijani,
Bengali, Brazilian Portuguese, Dutch, French, German, Greek, Polish,
Simplified Chinese, Swedish, Thai and Ukrainian.&lt;/p&gt;

&lt;p&gt;The &lt;a href=&quot;https://gitlab.com/gunnarwolf/madewithcc-es.git&quot;&gt;git
repository for the book&lt;/a&gt; contain all source files needed to build
the book for yourself.
&lt;a href=&quot;https://gunnarwolf.gitlab.io/madewithcc-es/&quot;&gt;HTML editions&lt;/a&gt;
to help with proof reading is also available.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
        </item>
        
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