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  13  <h1>
  14      <a href="https://people.skolelinux.org/pere/blog/">Petter Reinholdtsen</a>
  15
  16  </h1>
  17
  18 </div>
  19
  20
  21
  22     <div class="entry">
  23       <div class="title"><a href="https://people.skolelinux.org/pere/blog/LinuxCNC_MQTT_publisher_component.html">LinuxCNC MQTT publisher component</a></div>
  24       <div class="date"> 8th January 2023</div>
  25       <div class="body"><p>I watched <a href="https://yewtu.be/watch?v=jmKUV3aNLjk">a 2015
  26 video from Andreas Schiffler</a> the other day, where he set up
  27 <a href="https://linuxcnc.org/">LinuxCNC</a> to send status
  28 information to the MQTT broker IBM Bluemix.  As I also use MQTT for
  29 graphing, it occured to me that a generic MQTT LinuxCNC component
  30 would be useful and I set out to implement it.  Today I got the first
  31 draft limping along and submitted as
  32 <a href="https://github.com/LinuxCNC/linuxcnc/pull/2253">a patch to the
  33 LinuxCNC project</a>.</p>
  34
  35 <p>The simple part was setting up the MQTT publishing code in Python.
  36 I already have set up other parts submitting data to my Mosquito MQTT
  37 broker, so I could reuse that code.  Writing a LinuxCNC component in
  38 Python as new to me, but using existing examples in the code
  39 repository and the extensive documentation, this was fairly straight
  40 forward.  The hardest part was creating a automated test for the
  41 component to ensure it was working.  Testing it in a simulated
  42 LinuxCNC machine proved very useful, as I discovered features I needed
  43 that I had not thought of yet, and adjusted the code quite a bit to
  44 make it easier to test without a operational MQTT broker
  45 available.</p>
  46
  47 <p>The draft is ready and working, but I am unsure which LinuxCNC HAL
  48 pins I should collect and publish by default (in other words, the
  49 default set of information pieces published), and how to get the
  50 machine name from the LinuxCNC INI file.  The latter is a minor
  51 detail, but I expect it would be useful in a setup with several
  52 machines available.  I am hoping for feedback from the experienced
  53 LinuxCNC developers and users, to make the component even better
  54 before it can go into the mainland LinuxCNC code base.</p>
  55
  56 <p>Since I started on the MQTT component, I came across
  57 <a href="https://yewtu.be/watch?v=Bqa2grG0XtA">another video from Kent
  58 VanderVelden</a> where he combine LinuxCNC with a set of screen glasses
  59 controlled by a Raspberry Pi, and it occured to me that it would
  60 be useful for such use cases if LinuxCNC also provided a REST API for
  61 querying its status.  I hope to start on such component once the MQTT
  62 component is working well.</p>
  63
  64 <p>As usual, if you use Bitcoin and want to show your support of my
  65 activities, please send Bitcoin donations to my address
  66 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
  67 </div>
  68       <div class="tags">
  69
  70
  71         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/linuxcnc">linuxcnc</a>, <a href="https://people.skolelinux.org/pere/blog/tags/robot">robot</a>.
  72
  73
  74       </div>
  75     </div>
  76     <div class="padding"></div>
  77
  78     <div class="entry">
  79       <div class="title"><a href="https://people.skolelinux.org/pere/blog/ONVIF_IP_camera_management_tool_finally_in_Debian.html">ONVIF IP camera management tool finally in Debian</a></div>
  80       <div class="date">24th December 2022</div>
  81       <div class="body"><p>Merry Christmas to you all.  Here is a small gift to all those with
  82 IP cameras following the <a href="https://www.onvif.org/">ONVIF
  83 specification</a>.  There is finally a nice command line and GUI tool
  84 in Debian to manage ONVIF IP cameras.  After working with upstream for
  85 a few months and sponsoring the upload, I am very happy to report that
  86 the <a href="https://tracker.debian.org/libonvif">libonvif package</a>
  87 entered Debian Sid last night.</p>
  88
  89 <p>The package provide a C library to communicate with such cameras, a
  90 command line tool to locate and update settings of (like password) the
  91 cameras and a GUI tool to configure and control the units as well as
  92 preview the video from the camera.  Libonvif is available on Both
  93 Linux and Windows and the GUI tool uses the Qt library.  The main
  94 competitors are non-free software, while libonvif is GNU GPL licensed.
  95 I am very glad Debian users in the future can control their cameras
  96 using a free software system provided by Debian.  But the ONVIF world
  97 is full of slightly broken firmware, where the cameras pretend to
  98 follow the ONVIF specification but fail to set some configuration
  99 values or refuse to provide video to more than one recipient at the
 100 time, and the onvif project is quite young and might take a while
 101 before it completely work with your camera.  Upstream seem eager to
 102 improve the library, so handling any broken camera might be just <a
 103 href="https://github.com/sr99622/libonvif/">a bug report away</a>.</p>
 104
 105 <p>The package just cleared NEW, and need a new source only upload
 106 before it can enter testing.  This will happen in the next few
 107 days.</p>
 108
 109 <p>As usual, if you use Bitcoin and want to show your support of my
 110 activities, please send Bitcoin donations to my address
 111 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 112 </div>
 113       <div class="tags">
 114
 115
 116         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="https://people.skolelinux.org/pere/blog/tags/standard">standard</a>, <a href="https://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
 117
 118
 119       </div>
 120     </div>
 121     <div class="padding"></div>
 122
 123     <div class="entry">
 124       <div class="title"><a href="https://people.skolelinux.org/pere/blog/Managing_and_using_ONVIF_IP_cameras_with_Linux.html">Managing and using ONVIF IP cameras with Linux</a></div>
 125       <div class="date">19th October 2022</div>
 126       <div class="body"><p>Recently I have been looking at how to control and collect data
 127 from a handful IP cameras using Linux.  I both wanted to change their
 128 settings and to make their imagery available via a free software
 129 service under my control.  Here is a summary of the tools I found.</p>
 130
 131 <p>First I had to identify the cameras and their protocols.  As far as
 132 I could tell, they were using some SOAP looking protocol and their
 133 internal web server seem to only work with Microsoft Internet Explorer
 134 with some proprietary binary plugin, which in these days of course is
 135 a security disaster and also made it impossible for me to use the
 136 camera web interface.  Luckily I discovered that the SOAP looking
 137 protocol is actually following <a href="https://www.onvif.org/">the
 138 ONVIF specification</a>, which seem to be supported by a lot of IP
 139 cameras these days.</p>
 140
 141 <p>Once the protocol was identified, I was able to find what appear to
 142 be the most popular way to configure ONVIF cameras, the free software
 143 Windows tool named
 144 <a href="https://sourceforge.net/projects/onvifdm/">ONVIF Device
 145 Manager</a>.  Lacking any other options at the time, I tried
 146 unsuccessfully to get it running using Wine, but was missing a dotnet
 147 40 library and I found no way around it to run it on Linux.</p>
 148
 149 <p>The next tool I found to configure the cameras were a non-free Linux Qt
 150 client <a href="https://www.lingodigit.com/onvif_nvcdemo.html">ONVIF
 151 Device Tool</a>.  I did not like its terms of use, so did not spend
 152 much time on it.</p>
 153
 154 <p>To collect the video and make it available in a web interface, I
 155 found the Zoneminder tool in Debian.  A recent version was able to
 156 automatically detect and configure ONVIF devices, so I could use it to
 157 set up motion detection in and collection of the camera output.  I had
 158 initial problems getting the ONVIF autodetection to work, as both
 159 Firefox and Chromium <a href="https://bugs.debian.org/1001188">refused
 160 the inter-tab communication</a> being used by the Zoneminder web
 161 pages, but managed to get konqueror to work.  Apparently the "Enhanced
 162 Tracking Protection" in Firefox cause the problem.  I ended up
 163 upgrading to the Bookworm edition of Zoneminder in the process to try
 164 to fix the issue, and believe the problem might be solved now.</p>
 165
 166 <p>In the process I came across the nice Linux GUI tool
 167 <a href="https://gitlab.com/caspermeijn/onvifviewer/">ONVIF Viewer</a>
 168 allowing me to preview the camera output and validate the login
 169 passwords required.  Sadly its author has grown tired of maintaining
 170 the software, so it might not see any future updates.  Which is sad,
 171 as the viewer is sightly unstable and the picture tend to lock up.
 172 Note, this lockup might be due to limitations in the cameras and not
 173 the viewer implementation.  I suspect the camera is only able to
 174 provide pictures to one client at the time, and the Zoneminder feed
 175 might interfere with the GUI viewer.  I have
 176 <a href="https://bugs.debian.org/1000820">asked for the tool to be
 177 included in Debian</a>.</p>
 178
 179 <p>Finally, I found what appear to be very nice Linux free software
 180 replacement for the Windows tool, named
 181 <a href="https://github.com/sr99622/libonvif/">libonvif</a>.  It
 182 provide a C library to talk to ONVIF devices as well as a command line
 183 and GUI tool using the library.  Using the GUI tool I was able to change
 184 the admin passwords and update other settings of the cameras.  I have
 185 <a href="https://bugs.debian.org/1021980">asked for the package to be
 186 included in Debian</a>.</p>
 187
 188 <p>As usual, if you use Bitcoin and want to show your support of my
 189 activities, please send Bitcoin donations to my address
 190 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 191
 192 <p><strong>Update 2022-10-20</strong>: Since my initial publication of
 193 this text, I got several suggestions for more free software Linux
 194 tools.  There is <a href="https://github.com/quatanium/python-onvif">a
 195 ONVIF python library</a> (already
 196 <a href="https://bugs.debian.org/824240">requested into Debian</a>) and
 197 <a href="https://github.com/FalkTannhaeuser/python-onvif-zeep">a python 3
 198 fork</a> using a different SOAP dependency.  There is also
 199 <a href="https://www.home-assistant.io/integrations/onvif/">support for
 200 ONVIF in Home Assistant</a>, and there is an alternative to Zoneminder
 201 called <a href="https://www.shinobi.video/">Shinobi</a>.  The latter
 202 two are not included in Debian either.  I have not tested any of these
 203 so far.</p>
 204 </div>
 205       <div class="tags">
 206
 207
 208         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="https://people.skolelinux.org/pere/blog/tags/standard">standard</a>, <a href="https://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
 209
 210
 211       </div>
 212     </div>
 213     <div class="padding"></div>
 214
 215     <div class="entry">
 216       <div class="title"><a href="https://people.skolelinux.org/pere/blog/Time_to_translate_the_Bullseye_edition_of_the_Debian_Administrator_s_Handbook.html">Time to translate the Bullseye edition of the Debian Administrator's Handbook</a></div>
 217       <div class="date">12th September 2022</div>
 218       <div class="body"><p align="center"><img align="center" src="http://people.skolelinux.org/pere/blog/images/2020-10-20-debian-handbook-nb-testprint.jpeg" width="60%"/></p>
 219
 220 <p>(The picture is of the previous edition.)</p>
 221
 222 <p>Almost two years after the previous Norwegian Bokmål translation of
 223 the "<a href="https://debian-handbook.info/">The Debian Administrator's
 224 Handbook</a>" was published, a new edition is finally being prepared.  The
 225 english text is updated, and it is time to start working on the
 226 translations.  Around 37 percent of the strings have been updated, one
 227 way or another, and the translations starting from a complete Debian Buster
 228 edition now need to bring their translation up from 63% to 100%.  The
 229 complete book is licensed using a Creative Commons license, and has
 230 been published in several languages over the years.  The translations
 231 are done by volunteers to bring Linux in their native tongue.  The
 232 last time I checked, it complete text was available in English,
 233 Norwegian Bokmål, German, Indonesian, Brazil Portuguese and Spanish.
 234 In addition, work has been started for Arabic (Morocco), Catalan,
 235 Chinese (Simplified), Chinese (Traditional), Croatian, Czech, Danish,
 236 Dutch, French, Greek, Italian, Japanese, Korean, Persian, Polish,
 237 Romanian, Russian, Swedish, Turkish and Vietnamese.</p>
 238
 239 <p>The translation is conducted on
 240 <a href="https://hosted.weblate.org/projects/debian-handbook/">the
 241 hosted weblate project page</a>.  Prospective translators are
 242 recommeded to subscribe to
 243 <a href="http://lists.alioth.debian.org/mailman/listinfo/debian-handbook-translators">the
 244 translators mailing list</a> and should also check out
 245 <a href="https://debian-handbook.info/contribute/">the instructions for
 246 contributors</a>.</p>
 247
 248 <p>I am one of the Norwegian Bokmål translators of this book, and we
 249 have just started.  Your contribution is most welcome.</p>
 250
 251 <p>As usual, if you use Bitcoin and want to show your support of my
 252 activities, please send Bitcoin donations to my address
 253 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 254 </div>
 255       <div class="tags">
 256
 257
 258         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>.
 259
 260
 261       </div>
 262     </div>
 263     <div class="padding"></div>
 264
 265     <div class="entry">
 266       <div class="title"><a href="https://people.skolelinux.org/pere/blog/Automatic_LinuxCNC_servo_PID_tuning_.html">Automatic LinuxCNC servo PID tuning?</a></div>
 267       <div class="date">16th July 2022</div>
 268       <div class="body"><p>While working on a CNC with servo motors controlled by the
 269 <a href="https://en.wikipedia.org/wiki/LinuxCNC">LinuxCNC</a>
 270 <a href="https://en.wikipedia.org/wiki/PID_controller">PID
 271 controller</a>, I recently had to learn how to tune the collection of values
 272 that control such mathematical machinery that a PID controller is.  It
 273 proved to be a lot harder than I hoped, and I still have not succeeded
 274 in getting the Z PID controller to successfully defy gravity, nor X
 275 and Y to move accurately and reliably.  But while climbing up this
 276 rather steep learning curve, I discovered that some motor control
 277 systems are able to tune their PID controllers.  I got the impression
 278 from the documentation that LinuxCNC were not.  This proved to be not
 279 true.</p>
 280
 281 <p>The LinuxCNC
 282 <a href="http://linuxcnc.org/docs/html/man/man9/pid.9.html">pid
 283 component</a> is the recommended PID controller to use.  It uses eight
 284 constants <tt>Pgain</tt>, <tt>Igain</tt>, <tt>Dgain</tt>,
 285 <tt>bias</tt>, <tt>FF0</tt>, <tt>FF1</tt>, <tt>FF2</tt> and
 286 <tt>FF3</tt> to calculate the output value based on current and wanted
 287 state, and all of these need to have a sensible value for the
 288 controller to behave properly.  Note, there are even more values
 289 involved, theser are just the most important ones.  In my case I need
 290 the X, Y and Z axes to follow the requested path with little error.
 291 This has proved quite a challenge for someone who have never tuned a
 292 PID controller before, but there is at least some help to be found.
 293
 294 <p>I discovered that included in LinuxCNC was this old PID component
 295 at_pid claiming to have auto tuning capabilities.  Sadly it had been
 296 neglected since 2011, and could not be used as a plug in replacement
 297 for the default pid component.  One would have to rewriting the
 298 LinuxCNC HAL setup to test at_pid.  This was rather sad, when I wanted
 299 to quickly test auto tuning to see if it did a better job than me at
 300 figuring out good P, I and D values to use.</p>
 301
 302 <p>I decided to have a look if the situation could be improved.  This
 303 involved trying to understand the code and history of the pid and
 304 at_pid components.  Apparently they had a common ancestor, as code
 305 structure, comments and variable names were quite close to each other.
 306 Sadly this was not reflected in the git history, making it hard to
 307 figure out what really happened.  My guess is that the author of
 308 <a href="https://github.com/LinuxCNC/linuxcnc/blob/master/src/hal/components/at_pid.c">at_pid.c</a>
 309 took a version of
 310 <a href="https://github.com/LinuxCNC/linuxcnc/blob/master/src/hal/components/pid.c">pid.c</a>,
 311 rewrote it to follow the structure he wished pid.c to have, then added
 312 support for auto tuning and finally got it included into the LinuxCNC
 313 repository.  The restructuring and lack of early history made it
 314 harder to figure out which part of the code were relevant to the auto
 315 tuning, and which part of the code needed to be updated to work the
 316 same way as the current pid.c implementation.  I started by trying to
 317 isolate relevant changes in pid.c, and applying them to at_pid.c.  My
 318 aim was to make sure the at_pid component could replace the pid
 319 component with a simple change in the HAL setup loadrt line, without
 320 having to "rewire" the rest of the HAL configuration.  After a few
 321 hours following this approach, I had learned quite a lot about the
 322 code structure of both components, while concluding I was heading down
 323 the wrong rabbit hole, and should get back to the surface and find a
 324 different path.</p>
 325
 326 <p>For the second attempt, I decided to throw away all the PID control
 327 related part of the original at_pid.c, and instead isolate and lift
 328 the auto tuning part of the code and inject it into a copy of pid.c.
 329 This ensured compatibility with the current pid component, while
 330 adding auto tuning as a run time option.  To make it easier to identify
 331 the relevant parts in the future, I wrapped all the auto tuning code
 332 with '#ifdef AUTO_TUNER'.  The end result behave just like the current
 333 pid component by default, as that part of the code is identical.  The
 334 <a href="https://github.com/LinuxCNC/linuxcnc/pull/1820">end result
 335 entered the LinuxCNC master branch</a> a few days ago.</p>
 336
 337 <p>To enable auto tuning, one need to set a few HAL pins in the PID
 338 component.  The most important ones are <tt>tune-effort</tt>,
 339 <tt>tune-mode</tt> and <tt>tune-start</tt>.  But lets take a step
 340 back, and see what the auto tuning code will do.  I do not know the
 341 mathematical foundation of the at_pid algorithm, but from observation
 342 I can tell that the algorithm will, when enabled, produce a square
 343 wave pattern centered around the <tt>bias</tt> value on the output pin
 344 of the PID controller.  This can be seen using the HAL Scope provided
 345 by LinuxCNC.  In my case, this is translated into voltage (+-10V) sent
 346 to the motor controller, which in turn is translated into motor speed.
 347 So at_pid will ask the motor to move the axis back and forth.  The
 348 number of cycles in the pattern is controlled by the
 349 <tt>tune-cycles</tt> pin, and the extremes of the wave pattern is
 350 controlled by the <tt>tune-effort</tt> pin.  Of course, trying to
 351 change the direction of a physical object instantly (as in going
 352 directly from a positive voltage to the equivalent negative voltage)
 353 do not change velocity instantly, and it take some time for the object
 354 to slow down and move in the opposite direction.  This result in a
 355 more smooth movement wave form, as the axis in question were vibrating
 356 back and forth.  When the axis reached the target speed in the
 357 opposing direction, the auto tuner change direction again.  After
 358 several of these changes, the average time delay between the 'peaks'
 359 and 'valleys' of this movement graph is then used to calculate
 360 proposed values for Pgain, Igain and Dgain, and insert them into the
 361 HAL model to use by the pid controller.  The auto tuned settings are
 362 not great, but htye work a lot better than the values I had been able
 363 to cook up on my own, at least for the horizontal X and Y axis.  But I
 364 had to use very small <tt>tune-effort<tt> values, as my motor
 365 controllers error out if the voltage change too quickly.  I've been
 366 less lucky with the Z axis, which is moving a heavy object up and
 367 down, and seem to confuse the algorithm.  The Z axis movement became a
 368 lot better when I introduced a <tt>bias</tt> value to counter the
 369 gravitational drag, but I will have to work a lot more on the Z axis
 370 PID values.</p>
 371
 372 <p>Armed with this knowledge, it is time to look at how to do the
 373 tuning.  Lets say the HAL configuration in question load the PID
 374 component for X, Y and Z like this:</p>
 375
 376 <blockquote><pre>
 377 loadrt pid names=pid.x,pid.y,pid.z
 378 </pre></blockquote>
 379
 380 <p>Armed with the new and improved at_pid component, the new line will
 381 look like this:</p>
 382
 383 <blockquote><pre>
 384 loadrt at_pid names=pid.x,pid.y,pid.z
 385 </pre></blockquote>
 386
 387 <p>The rest of the HAL setup can stay the same.  This work because the
 388 components are referenced by name.  If the component had used count=3
 389 instead, all use of pid.# had to be changed to at_pid.#.</p>
 390
 391 <p>To start tuning the X axis, move the axis to the middle of its
 392 range, to make sure it do not hit anything when it start moving back
 393 and forth.  Next, set the <tt>tune-effort</tt> to a low number in the
 394 output range.  I used 0.1 as my initial value.  Next, assign 1 to the
 395 <tt>tune-mode</tt> value. Note, this will disable the pid controlling
 396 part and feed 0 to the output pin, which in my case initially caused a
 397 lot of drift.  In my case it proved to be a good idea with X and Y to
 398 tune the motor driver to make sure 0 voltage stopped the motor
 399 rotation.  On the other hand, for the Z axis this proved to be a bad
 400 idea, so it will depend on your setup.  It might help to set the
 401 <tt>bias</tt> value to a output value that reduce or eliminate the
 402 axis drift.  Finally, after setting <tt>tune-mode</tt>, set
 403 <tt>tune-start</tt> to 1 to activate the auto tuning.  If all go well,
 404 your axis will vibrate for a few seconds and when it is done, new
 405 values for Pgain, Igain and Dgain will be active.  To test them,
 406 change <tt>tune-mode</tt> back to 0.  Note that this might cause the
 407 machine to suddenly jerk as it bring the axis back to its commanded
 408 position, which it might have drifted away from during tuning.  To
 409 summarize with some halcmd lines:</p>
 410
 411 <blockquote><pre>
 412 setp pid.x.tune-effort 0.1
 413 setp pid.x.tune-mode 1
 414 setp pid.x.tune-start 1
 415 # wait for the tuning to complete
 416 setp pid.x.tune-mode 0
 417 </pre></blockquote>
 418
 419 <p>After doing this task quite a few times while trying to figure out
 420 how to properly tune the PID controllers on the machine in, I decided
 421 to figure out if this process could be automated, and wrote a script
 422 to do the entire tuning process from power on.  The end result will
 423 ensure the machine is powered on and ready to run, home all axis if it
 424 is not already done, check that the extra tuning pins are available,
 425 move the axis to its mid point, run the auto tuning and re-enable the
 426 pid controller when it is done.  It can be run several times.  Check
 427 out the
 428 <a href="https://github.com/SebKuzminsky/MazakVQC1540/blob/bon-dev/scripts/run-auto-pid-tuner">run-auto-pid-tuner</a>
 429 script on github if you want to learn how it is done.</p>
 430
 431 <p>My hope is that this little adventure can inspire someone who know
 432 more about motor PID controller tuning can implement even better
 433 algorithms for automatic PID tuning in LinuxCNC, making life easier
 434 for both me and all the others that want to use LinuxCNC but lack the
 435 in depth knowledge needed to tune PID controllers well.</p>
 436
 437 <p>As usual, if you use Bitcoin and want to show your support of my
 438 activities, please send Bitcoin donations to my address
 439 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 440 </div>
 441       <div class="tags">
 442
 443
 444         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer</a>, <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/linuxcnc">linuxcnc</a>, <a href="https://people.skolelinux.org/pere/blog/tags/robot">robot</a>.
 445
 446
 447       </div>
 448     </div>
 449     <div class="padding"></div>
 450
 451     <div class="entry">
 452       <div class="title"><a href="https://people.skolelinux.org/pere/blog/My_free_software_activity_of_late__2022_.html">My free software activity of late (2022)</a></div>
 453       <div class="date">20th June 2022</div>
 454       <div class="body"><p>I guess it is time to bring some light on the various free software
 455 and open culture activities and projects I have worked on or been
 456 involved in the last year and a half.</p>
 457
 458 <p>First, lets mention the book
 459 <a href="http://www.hungry.com/~pere/publisher/">releases I managed to
 460 publish</a>.  The Cory Doctorow book "Hvordan knuse
 461 overvåkningskapitalismen" argue that it is not the magic machine
 462 learning of the big technology companies that causes the surveillance
 463 capitalism to thrive, it is the lack of trust busting to enforce
 464 existing anti-monopoly laws.  I also published a family of
 465 dictionaries for machinists, one sorted on the English words, one
 466 sorted on the Norwegian and the last sorted on the North Sámi words.
 467 A bit on the back burner but not forgotten is the Debian
 468 Administrators Handbook, where a new edition is being worked on.  I
 469 have not spent as much time as I want to help bring it to completion,
 470 but hope I will get more spare time to look at it before the end of
 471 the year.</p>
 472
 473 <p>With my Debian had I have spent time on several projects, both
 474 updating existing packages, helping to bring in new packages and
 475 working with upstream projects to try to get them ready to go into
 476 Debian.  The list is rather long, and I will only mention my own
 477 isenkram, openmotor, vlc bittorrent plugin, xprintidle, norwegian
 478 letter style for latex, bs1770gain, and recordmydesktop.  In addition
 479 to these I have sponsored several packages into Debian, like audmes.</p>
 480
 481 <p>The last year I have looked at several infrastructure projects for
 482 collecting meter data and video surveillance recordings.  This include
 483 several ONVIF related tools like onvifviewer and zoneminder as well as
 484 rtl-433, wmbusmeters and rtl-wmbus.</p>
 485
 486 <p>In parallel with this I have looked at fabrication related free
 487 software solutions like pycam and LinuxCNC.  The latter recently
 488 gained improved translation support using po4a and weblate, which was
 489 a harder nut to crack that I had anticipated when I started.</p>
 490
 491 <p>Several hours have been spent translating free software to
 492 Norwegian Bokmål on the Weblate hosted service.  Do not have a
 493 complete list, but you will find my contributions in at least gnucash,
 494 minetest and po4a.</p>
 495
 496 <p>I also spent quite some time on the Norwegian archiving specification
 497 Noark 5, and its companion project Nikita implementing the API
 498 specification for Noark 5.</p>
 499
 500 <p>Recently I have been looking into free software tools to do company
 501 accounting here in Norway., which present an interesting mix between
 502 law, rules, regulations, format specifications and API interfaces.</p>
 503
 504 <p>I guess I should also mention the Norwegian community driven
 505 government interfacing projects Mimes Brønn and Fiksgatami, which have
 506 ended up in a kind of limbo while the future of the projects is being
 507 worked out.</p>
 508
 509 <p>These are just a few of the projects I have been involved it, and
 510 would like to give more visibility.  I'll stop here to avoid delaying
 511 this post.</p>
 512
 513 <p>As usual, if you use Bitcoin and want to show your support of my
 514 activities, please send Bitcoin donations to my address
 515 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 516 </div>
 517       <div class="tags">
 518
 519
 520         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>.
 521
 522
 523       </div>
 524     </div>
 525     <div class="padding"></div>
 526
 527     <div class="entry">
 528       <div class="title"><a href="https://people.skolelinux.org/pere/blog/LinuxCNC_translators_life_just_got_a_bit_easier.html">LinuxCNC translators life just got a bit easier</a></div>
 529       <div class="date"> 3rd June 2022</div>
 530       <div class="body"><p>Back in oktober last year, when I started looking at the
 531 <a href="https://en.wikipedia.org/wiki/LinuxCNC">LinuxCNC</a> system, I
 532 proposed to change the documentation build system make life easier for
 533 translators.  The original system consisted of independently written
 534 documentation files for each language, with no automated way to track
 535 changes done in other translations and no help for the translators to
 536 know how much was left to translated.  By using
 537 <a href="https://po4a.org/">the po4a system</a> to generate POT and PO
 538 files from the English documentation, this can be improved.  A small
 539 team of LinuxCNC contributors got together and today our labour
 540 finally payed off.  Since a few hours ago, it is now possible to
 541 translate <a href="https://hosted.weblate.org/projects/linuxcnc/">the
 542 LinuxCNC documentation on Weblate</a>, alongside the program itself.</p>
 543
 544 <p>The effort to migrate the documentation to use po4a has been both
 545 slow and frustrating.  I am very happy we finally made it.</p>
 546
 547 <p>As usual, if you use Bitcoin and want to show your support of my
 548 activities, please send Bitcoin donations to my address
 549 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 550 </div>
 551       <div class="tags">
 552
 553
 554         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer</a>, <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/linuxcnc">linuxcnc</a>, <a href="https://people.skolelinux.org/pere/blog/tags/robot">robot</a>.
 555
 556
 557       </div>
 558     </div>
 559     <div class="padding"></div>
 560
 561     <div class="entry">
 562       <div class="title"><a href="https://people.skolelinux.org/pere/blog/geteltorito_make_CD_firmware_upgrades_a_breeze.html">geteltorito make CD firmware upgrades a breeze</a></div>
 563       <div class="date">20th April 2022</div>
 564       <div class="body"><p>Recently I wanted to upgrade the firmware of my thinkpad, and
 565 located the firmware download page from Lenovo (which annoyingly do
 566 not allow access via Tor, forcing me to hand them more personal
 567 information that I would like).  The
 568 <a href="https://support.lenovo.com/no/en/search?query=thinkpad firmware bios upgrade iso&SearchType=Customer search&searchLocation=Masthead">download
 569 from Lenovo</a> is a bootable ISO image, which is a bit of a problem
 570 when all I got available is a USB memory stick.  I tried booting the
 571 ISO as a USB stick, but this did not work.  But genisoimage came to
 572 the rescue.</p>
 573
 574 <P>The geteltorito program in
 575 <a href="http://tracker.debian.org/cdrkit">the genisoimage binary
 576 package</a> is able to convert the bootable ISO image to a bootable
 577 USB stick using a simple command line recipe, which I then can write
 578 to the most recently inserted USB stick:</p>
 579
 580 <blockquote><pre>
 581 geteltorito -o usbstick.img lenovo-firmware.iso
 582 sudo dd bs=10M if=usbstick.img of=$(ls -tr /dev/sd?|tail -1)
 583 </pre></blockquote>
 584
 585 <p>This USB stick booted the firmware upgrader just fine, and in a few
 586 minutes my machine had the latest and greatest BIOS firmware in place.</p>
 587 </div>
 588       <div class="tags">
 589
 590
 591         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>.
 592
 593
 594       </div>
 595     </div>
 596     <div class="padding"></div>
 597
 598     <div class="entry">
 599       <div class="title"><a href="https://people.skolelinux.org/pere/blog/Playing_and_encoding_AV1_in_Debian_Bullseye.html">Playing and encoding AV1 in Debian Bullseye</a></div>
 600       <div class="date">16th April 2022</div>
 601       <div class="body"><p>Inspired by the recent news of
 602 <a href="https://slashdot.org/story/22/04/03/2039219/intel-beats-amd-and-nvidia-with-arc-gpus-full-av1-support">AV1
 603 hardware encoding support from Intel</a>, I decided to look into
 604 the state of AV1 on Linux today.  AV1 is a
 605 <a href="https://web.archive.org/web/20160618103850/http://www.digistan.org/open-standard:definition">free
 606 and open standard</a> as defined by Digistan without any royalty
 607 payment requirement, unlike its much used competitor encoding
 608 H.264.  While looking, I came across an 5 year
 609 <a href="https://askubuntu.com/questions/1061908/how-to-encode-and-playback-video-with-the-av1-codec-on-bionic-beaver-18-04">old
 610 question on askubuntu.com</a> which in turn inspired me to check out
 611 how things are in Debian Stable regarding AV1.  The test file listed
 612 in the question (askubuntu_test_aom.mp4) did not exist any more, so I
 613 tracked down a different set of test files on
 614 <a href="https://av1.webmfiles.org/">av1.webmfiles.org</a> to test them
 615 with the various video tools I had installed on my machine.  I was
 616 happy to discover that AV1 decoding and playback worked with almost
 617 every tool I tested:
 618
 619 <table align="center">
 620 <tr><td>mediainfo</td>       <td>ok</td></tr>
 621 <tr><td>dragonplayer</td>    <td>ok</td></tr>
 622 <tr><td>ffmpeg / ffplay</td> <td>ok</td></tr>
 623 <tr><td>gnome-mplayer</td>   <td>fail</td></tr>
 624 <tr><td>mplayer</td>         <td>ok</td></tr>
 625 <tr><td>mpv</td>             <td>ok</td></tr>
 626 <tr><td>parole</td>          <td>ok</td></tr>
 627 <tr><td>vlc</td>             <td>ok</td></tr>
 628 <tr><td>firefox</td>         <td>ok</td></tr>
 629 <tr><td>chromium</td>        <td>ok</td></tr>
 630 </table>
 631
 632 <p>AV1 encoding is available in Debian Stable from the aom-tools
 633 version 1.0.0.errata1-3 package, using the aomenc tool.  The encoding
 634 using the package in Debian Stable is quite slow, with the frame rate
 635 for my 10 second test video at around 0.25 fps.  My 10 second video
 636 test took 16 minutes and 11 seconds on my test machine.</p>
 637
 638 <p>I tested by first running ffmpeg and then aomenc using the recipe
 639 provided by the askubuntu recipe above.  I had to remove the
 640 '--row-mt=1' option, as it was not supported in my 1.0.0 version.  The
 641 encoding only used a single thread, according to <tt>top</tt>.</p>
 642
 643 <blockquote><pre>
 644 ffmpeg -i some-old-video.ogv -t 10 -pix_fmt yuv420p video.y4m
 645 aomenc --fps=24/1 -u 0 --codec=av1 --target-bitrate=1000 \
 646   --lag-in-frames=25 --auto-alt-ref=1 -t 24 --cpu-used=8 \
 647   --tile-columns=2 --tile-rows=2 -o output.webm video.y4m
 648 </pre></blockquote>
 649
 650 <p>As version 1.0.0 currently have several
 651 <a href="https://security-tracker.debian.org/tracker/source-package/aom">unsolved
 652 security issues in Debian Stable</a>, and to see if the recent
 653 backport <a href="https://tracker.debian.org/pkg/aom">provided in
 654 Debian</a> is any quicker, I ran <tt>apt -t bullseye-backports install
 655 aom-tools</tt> to fetch the backported version and re-encoded the
 656 video using the latest version.  This time the '--row-mt=1' option
 657 worked, and the encoding was done in 46 seconds with a frame rate of
 658 around 5.22 fps.  This time it seem to be using all my four cores to
 659 encode.  Encoding speed is still too low for streaming and real time,
 660 which would require frame rates above 25 fps, but might be good enough
 661 for offline encoding.</p>
 662
 663 <p>I am very happy to see AV1 playback working so well with the
 664 default tools in Debian Stable.  I hope the encoding situation improve
 665 too, allowing even a slow old computer like my 10 year old laptop to
 666 be used for encoding.</p>
 667
 668 <p>As usual, if you use Bitcoin and want to show your support of my
 669 activities, please send Bitcoin donations to my address
 670 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
 671 </div>
 672       <div class="tags">
 673
 674
 675         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="https://people.skolelinux.org/pere/blog/tags/standard">standard</a>, <a href="https://people.skolelinux.org/pere/blog/tags/video">video</a>.
 676
 677
 678       </div>
 679     </div>
 680     <div class="padding"></div>
 681
 682     <div class="entry">
 683       <div class="title"><a href="https://people.skolelinux.org/pere/blog/F__en_slutt_p__Digitale_utslipp.html">Få en slutt på Digitale utslipp</a></div>
 684       <div class="date">14th March 2022</div>
 685       <div class="body"><p>På onsdag sendte jeg følgende epost til Utdanningsetaten i Oslo
 686 kommune (UDE).  Fikk beskjed om at min henvendelse har saksnummer
 687 22/7559-1 i den
 688 <a href="https://www.oslo.kommune.no/etater-foretak-og-ombud/utdanningsetaten/postjournal-utdanningsetaten/">offentlige
 689 postjournalen til UDE</a>.  Jeg er spent på hva slags respons jeg får.
 690 Mistenker jo de fleste som sprer sine nettsideleseres
 691 personopplysninger til utlandet ikke har tenkt så nøye igjennom hva de
 692 gjør, og at det er håp om at de tenker seg litt nøyere om hvis de blir
 693 klar over problemstillingen.  Vet du noen som burde få tilsvarede
 694 beskjed og spørsmål?  Kanskje du kan sende dem en epost.  Hvis alle
 695 bidrar blir det kanskje litt bedre.</p>
 696
 697 <blockquote>
 698 <p>To: postmottak (at) osloskolen.no
 699 <br>Subject: Digitale utslipp fra osloskolens nettsider</p>
 700
 701 <p>Hei.</p>
 702
 703 <p>Jeg ser at osloskolens nettsider har digitale utslipp av
 704 personopplysninger til Google, Facebook og andre, blant annet omtalt
 705 på &lt;URL: <a href="https://aktuelt.osloskolen.no/personvernerklaring-for-osloskolen/informasjonskapsler/">https://aktuelt.osloskolen.no/personvernerklaring-for-osloskolen/informasjonskapsler/</a>
 706 >.</p>
 707
 708 <p>&lt;URL: <a href="https://webbkoll.dataskydd.net/">https://webbkoll.dataskydd.net/</a> > kan være et nyttig verktøy for å holde øye med utslippsomfanget på ulike sider.</p>
 709
 710 <p>Kanskje det er en ide å gjøre noe med det, jamfør &lt;URL: <a href="https://www.digi.no/artikler/debatt-det-enkleste-tiltaket-er-a-skru-av-google-analytics/517378">https://www.digi.no/artikler/debatt-det-enkleste-tiltaket-er-a-skru-av-google-analytics/517378</a> >?</p>
 711
 712 <p>Et alternativ til Google Analytics kan være en lokalt installert
 713 utgave av &lt;URL:
 714 <a href="https://matomo.org/">https://matomo.org/</a> >.  Den og flere
 715 andre alternativer kan finnes via
 716 &lt;URL: <a href="https://www.digi.no/artikler/sverige-vil-skrote-amerikansk-skytjeneste-her-er-alternativene/516223?key=5QsV0wRG">https://www.digi.no/artikler/sverige-vil-skrote-amerikansk-skytjeneste-her-er-alternativene/516223?key=5QsV0wRG</a> >
 717 på bakgrunn av at svenske myndigheter har innsett at dagens praksis
 718 nok er både lite lur og ulovlig.  Der henger Norge litt etter, men
 719 osloskolen har her mulighet til å være litt i forkant. :)</p>
 720
 721 <p>Fint om dere kan gi beskjed hvilket saksnummer denne henvendelsen får i
 722 offentlig postjournal når den er mottatt.</p>
 723
 724 </blockquote>
 725
 726 </p>Flere og flere innser at slik spredning av personopplysninger er
 727 ugreit.  Det har pågått i mange år.  Ser jeg blogget
 728 <a href="https://people.skolelinux.org/pere/blog/Det_er_jo_makta_som_er_mest_s_rbar_ved_massiv_overv_kning_av_Internett.html">første
 729 gang om Google Analytics i 2013</a> og
 730 <a href="https://people.skolelinux.org/pere/blog/Snurpenot_overv_kning_av_sensitiv_personinformasjon.html">analyserte
 731 omfanget i 2015</a>, men det er et langt lerret å bleke.</p>
 732
 733 <p>Som vanlig, hvis du bruker Bitcoin og ønsker å vise din støtte til
 734 det jeg driver med, setter jeg pris på om du sender Bitcoin-donasjoner
 735 til min adresse
 736 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.
 737 Merk, betaling med bitcoin er ikke anonymt. :)</p>
 738 </div>
 739       <div class="tags">
 740
 741
 742         Tags: <a href="https://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="https://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="https://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
 743
 744
 745       </div>
 746     </div>
 747     <div class="padding"></div>
 748
 749     <p style="text-align: right;"><a href="index.rss"><img src="https://people.skolelinux.org/pere/blog/xml.gif" alt="RSS feed" width="36" height="14" /></a></p>
 750     <div id="sidebar">
 751
 752
 753
 754 <h2>Archive</h2>
 755 <ul>
 756
 757 <li>2023
 758 <ul>
 759
 760 <li><a href="https://people.skolelinux.org/pere/blog/archive/2023/01/">January (1)</a></li>
 761
 762 </ul></li>
 763
 764 <li>2022
 765 <ul>
 766
 767 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/02/">February (1)</a></li>
 768
 769 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/03/">March (3)</a></li>
 770
 771 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/04/">April (2)</a></li>
 772
 773 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/06/">June (2)</a></li>
 774
 775 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/07/">July (1)</a></li>
 776
 777 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/09/">September (1)</a></li>
 778
 779 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/10/">October (1)</a></li>
 780
 781 <li><a href="https://people.skolelinux.org/pere/blog/archive/2022/12/">December (1)</a></li>
 782
 783 </ul></li>
 784
 785 <li>2021
 786 <ul>
 787
 788 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/01/">January (2)</a></li>
 789
 790 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/02/">February (1)</a></li>
 791
 792 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/05/">May (1)</a></li>
 793
 794 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/06/">June (1)</a></li>
 795
 796 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/07/">July (3)</a></li>
 797
 798 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/08/">August (1)</a></li>
 799
 800 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/09/">September (1)</a></li>
 801
 802 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/10/">October (1)</a></li>
 803
 804 <li><a href="https://people.skolelinux.org/pere/blog/archive/2021/12/">December (1)</a></li>
 805
 806 </ul></li>
 807
 808 <li>2020
 809 <ul>
 810
 811 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/02/">February (2)</a></li>
 812
 813 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/03/">March (2)</a></li>
 814
 815 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/04/">April (2)</a></li>
 816
 817 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/05/">May (3)</a></li>
 818
 819 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/06/">June (2)</a></li>
 820
 821 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/07/">July (1)</a></li>
 822
 823 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/09/">September (1)</a></li>
 824
 825 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/10/">October (1)</a></li>
 826
 827 <li><a href="https://people.skolelinux.org/pere/blog/archive/2020/11/">November (1)</a></li>
 828
 829 </ul></li>
 830
 831 <li>2019
 832 <ul>
 833
 834 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/01/">January (4)</a></li>
 835
 836 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/02/">February (3)</a></li>
 837
 838 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/03/">March (3)</a></li>
 839
 840 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/05/">May (2)</a></li>
 841
 842 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/06/">June (5)</a></li>
 843
 844 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/07/">July (2)</a></li>
 845
 846 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/08/">August (1)</a></li>
 847
 848 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/09/">September (1)</a></li>
 849
 850 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/11/">November (1)</a></li>
 851
 852 <li><a href="https://people.skolelinux.org/pere/blog/archive/2019/12/">December (4)</a></li>
 853
 854 </ul></li>
 855
 856 <li>2018
 857 <ul>
 858
 859 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/01/">January (1)</a></li>
 860
 861 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/02/">February (5)</a></li>
 862
 863 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/03/">March (5)</a></li>
 864
 865 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/04/">April (3)</a></li>
 866
 867 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/06/">June (2)</a></li>
 868
 869 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/07/">July (5)</a></li>
 870
 871 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/08/">August (3)</a></li>
 872
 873 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/09/">September (3)</a></li>
 874
 875 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/10/">October (5)</a></li>
 876
 877 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/11/">November (2)</a></li>
 878
 879 <li><a href="https://people.skolelinux.org/pere/blog/archive/2018/12/">December (4)</a></li>
 880
 881 </ul></li>
 882
 883 <li>2017
 884 <ul>
 885
 886 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/01/">January (4)</a></li>
 887
 888 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/02/">February (3)</a></li>
 889
 890 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/03/">March (5)</a></li>
 891
 892 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/04/">April (2)</a></li>
 893
 894 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/06/">June (5)</a></li>
 895
 896 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/07/">July (1)</a></li>
 897
 898 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/08/">August (1)</a></li>
 899
 900 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/09/">September (3)</a></li>
 901
 902 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/10/">October (5)</a></li>
 903
 904 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/11/">November (3)</a></li>
 905
 906 <li><a href="https://people.skolelinux.org/pere/blog/archive/2017/12/">December (4)</a></li>
 907
 908 </ul></li>
 909
 910 <li>2016
 911 <ul>
 912
 913 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/01/">January (3)</a></li>
 914
 915 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/02/">February (2)</a></li>
 916
 917 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/03/">March (3)</a></li>
 918
 919 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/04/">April (8)</a></li>
 920
 921 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/05/">May (8)</a></li>
 922
 923 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/06/">June (2)</a></li>
 924
 925 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/07/">July (2)</a></li>
 926
 927 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/08/">August (5)</a></li>
 928
 929 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/09/">September (2)</a></li>
 930
 931 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/10/">October (3)</a></li>
 932
 933 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/11/">November (8)</a></li>
 934
 935 <li><a href="https://people.skolelinux.org/pere/blog/archive/2016/12/">December (5)</a></li>
 936
 937 </ul></li>
 938
 939 <li>2015
 940 <ul>
 941
 942 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/01/">January (7)</a></li>
 943
 944 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/02/">February (6)</a></li>
 945
 946 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/03/">March (1)</a></li>
 947
 948 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/04/">April (4)</a></li>
 949
 950 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/05/">May (3)</a></li>
 951
 952 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/06/">June (4)</a></li>
 953
 954 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/07/">July (6)</a></li>
 955
 956 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/08/">August (2)</a></li>
 957
 958 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/09/">September (2)</a></li>
 959
 960 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/10/">October (9)</a></li>
 961
 962 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/11/">November (6)</a></li>
 963
 964 <li><a href="https://people.skolelinux.org/pere/blog/archive/2015/12/">December (3)</a></li>
 965
 966 </ul></li>
 967
 968 <li>2014
 969 <ul>
 970
 971 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/01/">January (2)</a></li>
 972
 973 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/02/">February (3)</a></li>
 974
 975 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/03/">March (8)</a></li>
 976
 977 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/04/">April (7)</a></li>
 978
 979 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/05/">May (1)</a></li>
 980
 981 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/06/">June (2)</a></li>
 982
 983 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/07/">July (2)</a></li>
 984
 985 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/08/">August (2)</a></li>
 986
 987 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/09/">September (5)</a></li>
 988
 989 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/10/">October (6)</a></li>
 990
 991 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/11/">November (3)</a></li>
 992
 993 <li><a href="https://people.skolelinux.org/pere/blog/archive/2014/12/">December (5)</a></li>
 994
 995 </ul></li>
 996
 997 <li>2013
 998 <ul>
 999
1000 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/01/">January (11)</a></li>
1001
1002 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/02/">February (9)</a></li>
1003
1004 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/03/">March (9)</a></li>
1005
1006 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/04/">April (6)</a></li>
1007
1008 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/05/">May (9)</a></li>
1009
1010 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/06/">June (10)</a></li>
1011
1012 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/07/">July (7)</a></li>
1013
1014 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/08/">August (3)</a></li>
1015
1016 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/09/">September (5)</a></li>
1017
1018 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/10/">October (7)</a></li>
1019
1020 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/11/">November (9)</a></li>
1021
1022 <li><a href="https://people.skolelinux.org/pere/blog/archive/2013/12/">December (3)</a></li>
1023
1024 </ul></li>
1025
1026 <li>2012
1027 <ul>
1028
1029 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/01/">January (7)</a></li>
1030
1031 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/02/">February (10)</a></li>
1032
1033 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/03/">March (17)</a></li>
1034
1035 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/04/">April (12)</a></li>
1036
1037 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/05/">May (12)</a></li>
1038
1039 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/06/">June (20)</a></li>
1040
1041 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/07/">July (17)</a></li>
1042
1043 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/08/">August (6)</a></li>
1044
1045 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/09/">September (9)</a></li>
1046
1047 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/10/">October (17)</a></li>
1048
1049 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/11/">November (10)</a></li>
1050
1051 <li><a href="https://people.skolelinux.org/pere/blog/archive/2012/12/">December (7)</a></li>
1052
1053 </ul></li>
1054
1055 <li>2011
1056 <ul>
1057
1058 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/01/">January (16)</a></li>
1059
1060 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/02/">February (6)</a></li>
1061
1062 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/03/">March (6)</a></li>
1063
1064 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/04/">April (7)</a></li>
1065
1066 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/05/">May (3)</a></li>
1067
1068 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/06/">June (2)</a></li>
1069
1070 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/07/">July (7)</a></li>
1071
1072 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/08/">August (6)</a></li>
1073
1074 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/09/">September (4)</a></li>
1075
1076 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/10/">October (2)</a></li>
1077
1078 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/11/">November (3)</a></li>
1079
1080 <li><a href="https://people.skolelinux.org/pere/blog/archive/2011/12/">December (1)</a></li>
1081
1082 </ul></li>
1083
1084 <li>2010
1085 <ul>
1086
1087 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
1088
1089 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
1090
1091 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
1092
1093 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
1094
1095 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
1096
1097 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
1098
1099 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
1100
1101 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/08/">August (13)</a></li>
1102
1103 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/09/">September (7)</a></li>
1104
1105 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/10/">October (9)</a></li>
1106
1107 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/11/">November (13)</a></li>
1108
1109 <li><a href="https://people.skolelinux.org/pere/blog/archive/2010/12/">December (12)</a></li>
1110
1111 </ul></li>
1112
1113 <li>2009
1114 <ul>
1115
1116 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
1117
1118 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
1119
1120 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
1121
1122 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
1123
1124 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
1125
1126 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
1127
1128 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
1129
1130 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
1131
1132 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
1133
1134 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
1135
1136 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
1137
1138 <li><a href="https://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
1139
1140 </ul></li>
1141
1142 <li>2008
1143 <ul>
1144
1145 <li><a href="https://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
1146
1147 <li><a href="https://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
1148
1149 </ul></li>
1150
1151 </ul>
1152
1153
1154
1155 <h2>Tags</h2>
1156 <ul>
1157
1158  <li><a href="https://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (19)</a></li>
1159
1160  <li><a href="https://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
1161
1162  <li><a href="https://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
1163
1164  <li><a href="https://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
1165
1166  <li><a href="https://people.skolelinux.org/pere/blog/tags/betalkontant">betalkontant (9)</a></li>
1167
1168  <li><a href="https://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (12)</a></li>
1169
1170  <li><a href="https://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (17)</a></li>
1171
1172  <li><a href="https://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
1173
1174  <li><a href="https://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
1175
1176  <li><a href="https://people.skolelinux.org/pere/blog/tags/debian">debian (185)</a></li>
1177
1178  <li><a href="https://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (159)</a></li>
1179
1180  <li><a href="https://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (9)</a></li>
1181
1182  <li><a href="https://people.skolelinux.org/pere/blog/tags/digistan">digistan (11)</a></li>
1183
1184  <li><a href="https://people.skolelinux.org/pere/blog/tags/dld">dld (18)</a></li>
1185
1186  <li><a href="https://people.skolelinux.org/pere/blog/tags/docbook">docbook (30)</a></li>
1187
1188  <li><a href="https://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
1189
1190  <li><a href="https://people.skolelinux.org/pere/blog/tags/english">english (441)</a></li>
1191
1192  <li><a href="https://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
1193
1194  <li><a href="https://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (14)</a></li>
1195
1196  <li><a href="https://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (34)</a></li>
1197
1198  <li><a href="https://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
1199
1200  <li><a href="https://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (20)</a></li>
1201
1202  <li><a href="https://people.skolelinux.org/pere/blog/tags/h264">h264 (20)</a></li>
1203
1204  <li><a href="https://people.skolelinux.org/pere/blog/tags/intervju">intervju (43)</a></li>
1205
1206  <li><a href="https://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (16)</a></li>
1207
1208  <li><a href="https://people.skolelinux.org/pere/blog/tags/kart">kart (23)</a></li>
1209
1210  <li><a href="https://people.skolelinux.org/pere/blog/tags/kodi">kodi (4)</a></li>
1211
1212  <li><a href="https://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
1213
1214  <li><a href="https://people.skolelinux.org/pere/blog/tags/lego">lego (5)</a></li>
1215
1216  <li><a href="https://people.skolelinux.org/pere/blog/tags/lenker">lenker (8)</a></li>
1217
1218  <li><a href="https://people.skolelinux.org/pere/blog/tags/linuxcnc">linuxcnc (4)</a></li>
1219
1220  <li><a href="https://people.skolelinux.org/pere/blog/tags/lsdvd">lsdvd (2)</a></li>
1221
1222  <li><a href="https://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
1223
1224  <li><a href="https://people.skolelinux.org/pere/blog/tags/madewithcc">madewithcc (3)</a></li>
1225
1226  <li><a href="https://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
1227
1228  <li><a href="https://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (44)</a></li>
1229
1230  <li><a href="https://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (13)</a></li>
1231
1232  <li><a href="https://people.skolelinux.org/pere/blog/tags/noark5">noark5 (23)</a></li>
1233
1234  <li><a href="https://people.skolelinux.org/pere/blog/tags/norsk">norsk (320)</a></li>
1235
1236  <li><a href="https://people.skolelinux.org/pere/blog/tags/nuug">nuug (198)</a></li>
1237
1238  <li><a href="https://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (40)</a></li>
1239
1240  <li><a href="https://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
1241
1242  <li><a href="https://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (75)</a></li>
1243
1244  <li><a href="https://people.skolelinux.org/pere/blog/tags/personvern">personvern (114)</a></li>
1245
1246  <li><a href="https://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
1247
1248  <li><a href="https://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
1249
1250  <li><a href="https://people.skolelinux.org/pere/blog/tags/reprap">reprap (11)</a></li>
1251
1252  <li><a href="https://people.skolelinux.org/pere/blog/tags/rfid">rfid (3)</a></li>
1253
1254  <li><a href="https://people.skolelinux.org/pere/blog/tags/robot">robot (17)</a></li>
1255
1256  <li><a href="https://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
1257
1258  <li><a href="https://people.skolelinux.org/pere/blog/tags/ruter">ruter (7)</a></li>
1259
1260  <li><a href="https://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
1261
1262  <li><a href="https://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (59)</a></li>
1263
1264  <li><a href="https://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
1265
1266  <li><a href="https://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (5)</a></li>
1267
1268  <li><a href="https://people.skolelinux.org/pere/blog/tags/standard">standard (74)</a></li>
1269
1270  <li><a href="https://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (7)</a></li>
1271
1272  <li><a href="https://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (14)</a></li>
1273
1274  <li><a href="https://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (64)</a></li>
1275
1276  <li><a href="https://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (5)</a></li>
1277
1278  <li><a href="https://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
1279
1280  <li><a href="https://people.skolelinux.org/pere/blog/tags/valg">valg (9)</a></li>
1281
1282  <li><a href="https://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (20)</a></li>
1283
1284  <li><a href="https://people.skolelinux.org/pere/blog/tags/video">video (77)</a></li>
1285
1286  <li><a href="https://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
1287
1288  <li><a href="https://people.skolelinux.org/pere/blog/tags/web">web (42)</a></li>
1289
1290 </ul>
1291
1292
1293     </div>
1294     <p style="text-align: right">
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