koldfront

Upgrading to OpenWrt 21.02.0 #hardware #wifi

🕢︎ - 2021-09-11

A week ago ago the OpenWrt project released a major new version, 21.02.0.

I used the firmware selector to download a "SYSUPGRADE" file, but when I tried uploading it on my Netgear R6350, running OpenWrt 19.07.06, I got an error.

Searching for that error revealed that I had to install from scratch instead of upgrading, due to a change in how networking is configured. So I decided to postpone updating until I had plenty of time.

Today I had plenty of time. And spent it.

Instead of thinking, I uploaded the second package I downloaded when I read the announcement and just overrode all the warnings. Bad move - the access point didn't come back online after that.

I had chosen the wrong package - I should have taken the "KERNEL (SQUASHFS)", but instead I went for the "KERNEL (INITRAMFS)". I'm not sure how I made that mistake, but, alas, I did.

After trying to trigger failsafe mode and performing a factory reset when that didn't work, without any luck, I took the access point apart and located the place to solder on pins for serial port access.

Luckily I found a nice slide deck showing exactly how to figure out which pin is which with a multi-meter, and I dug out an old serial-usb dongle, some wires and my basic soldering iron.

However, soldering wires onto pcb's is not something I have attempted before (I've used the soldering iron to make a cable for my Amiga 500 to make the keyboard "external" in the 1990's, and then I've cobbled together a cable for controlling my amplifier, and that's my complete soldering experience). So before going further down that route, I looked into one more debricking strategy, using the nmrpflash tool, which conveniently is readily available in Debian.

I didn't have high hopes, because I saw no evidence of the access point jumping into the network with tcpdump, but I thought I might as well try it.

In the first attempt I saw something transferred!

It ended with an error, so I tried a couple of more times, which also ended with errors, but something worked, and the access point started blinking, and then came up with OpenWrt 21.02.0 on 192.168.1.1!

After configuring it and testing that it worked, I put it back together and hung it where it belongs. I even got opkg update working, so I could install the crelay-package that I use to automatically control the power to my printer.

It could have taken 5 minutes, if I had taken the warnings seriously and double checked the file I was uploading. Instead I spent most of the afternoon recovering from my mistake. But it's working as it should now, so all's well that ends well, I guess.

Turning heatwave data into information #climate crisis

🕥︎ - 2021-08-22

Professor of Atmospheric Sciences Andrew Dessler calmly takes down Ph.D. in political science Bjørn Lomborg's cherry picked, flawed EPA heatwave graph.

Tellingly Bjørn Lomborg engages with petty replies in a tweet exchange about it ("Wow so you're literally saying it is not okay to use EPA data") - a good indication that his goal is attention rather than knowledge.

The graph reflects some choices in interpretation of the raw data, which makes the reply facetious: it's not just raw data, it's data interpreted into information in a way that may or may not be meaningful, which is what is discussed by the other party.

But this is how we've always known Bjørn Lomborg - his whole spiel is "do cost/benefit analysis' and conclude that nothing can be done and everything will be fine due to future inventions" and conveniently show only information supporting that stance.

It is hard to tell if he is stupid, evil, or an attention seeking troll. In this case, I am having a hard time applying Hanlon's razor.

Servers upgraded to Debian 11 (bullseye) #debian

🕑︎ - 2021-08-21

Last weekend Debian released version 11 (bullseye).

After the release I upgraded my two small VPS's, which was smooth as can be - they only run bind and Postfix, plus one of them runs Jitsi.

I postponed the upgrade of my main/home server until today, a week later.

Upgrading was reasonably smooth this time, so far I have only had these problems:

  • I had to update my ejabberd.yml configuration file manually to make ejabberd start - that took a while, as it has changed quite a bit (mostly comments, though).
  • I had to update my radicale/config file manually in similar fashion, and it no longer supports sha1 in the htpasswd file (but still md5!?) - so I switched to bcrypt. After that it failed on VCARD entries with no UID, so I added those to the various VCARD files.
  • The old Hatta instance I run needed a libapache2-mod-wsgi - which doesn't exist in Debian any more, as Python 2.7 is gone. I had to "forward-port" the package from Debian 10. It seems to run with the virtual environment I created during the last upgrade.
  • Apache::Gallery uses Text::Template, which had to be patched to work around taint mode (again).
  • For weewex I had to update the weewx-sdr plugin to match the output of the newer rtl_433 - 3 patches sent to the author.

I had to build all my Haskell-based websites again with cabal new-build and adjust the paths to the binaries.

Interestingly, this time around none of my Perl based websites broke.

I Love Liz Climo's Comics #comics #rss

🕤︎ - 2021-08-14

Like this one:

They are a delight.

Follow by RSS - or by nntp on Feedbase.



War of the Twins (1986) ★☆☆☆☆ #books

🕡︎ - 2021-08-04

The second book in the Dragon Lance Legends trilogy is called War of the Twins.

To me it seems like the authors have written themselves into a corner, where the logic of time travel makes the story too convoluted and not interesting enough.

Perhaps science fiction writers are better at integrating time travel into their stories? For me it doesn't work here - I preferred the first trilogy, Dragon Lance Chronicles, which was perhaps simpler and maybe less ambitious, but did what it did better.

★☆☆☆☆

Rereading this book now, I think I know why I don't have the third book in this trilogy. This trilogy never really took off for me, and I think I simply didn't buy last book.

Remote controlling an NAD C 320BEE amplifier #jukebox

🕞︎ - 2021-07-14

For my jukebox I'm using an old(ish) NAD C 320BEE amplifier, which works fine except for one thing: when it is powered on, it starts up in "sleep mode", with no input selected and buzzing speakers.

Quite annoying, because I would like the Raspberry Pi to turn on the amplifier and (active) speakers when the jukebox is unpaused and turn them off when the sound is paused, using one of those nifty usb relays.

I noticed that the amplifier has an "IR in"-socket, so I started wondering if that could be used to control it.

And it can!

After looking at Pete Shadbolt's configuration (thanks!), I did this:

  • Installed lirc on the Raspberry Pi: sudo apt install lirc.
  • Configured /boot/config.txt adding the line dtoverlay=gpio-ir-tx,gpio_pin=22 to enable the gpio-ir-tx module and select the relevant pin
  • Changed /etc/lirc/lirc_options.conf with driver = default
  • Added /etc/lirc/lircd.conf.d/nad_sr712.conf from lirc's list

I found an old audio cable with a 3.5 mm jack in one end, and soldered two jumper wires to it, and connected the center of the jack to pin 22 on the Raspberry Pi and the top of the jack to a GND pin.

After rebooting the Raspberry Pi, I can now run commands like this:

jukebox:~$ irsend SEND_ONCE NAD_SR712 Input-Aux
jukebox:~$ irsend SEND_ONCE NAD_SR712 KEY_VOLUMEDOWN
jukebox:~$ irsend SEND_ONCE NAD_SR712 KEY_VOLUMEUP
jukebox:~$ irsend SEND_ONCE NAD_SR712 KEY_MUTE
jukebox:~$ irsend SEND_ONCE NAD_SR712 KEY_SLEEP

and the amplifier reacts. At least it does if I don't send them in too close succession.

To wake up the amplifier when I turn on the power, I have added a file /etc/systemd/system/amplifier.service with this in it:

[Unit]
Description=Set up amplifier
After=lircd.service

[Service]
Type=oneshot
RemainAfterExit=true
ExecStart=/home/asjo/bin/setup_amp
ExecStop=/usr/bin/irsend SEND_ONCE NAD_SR712 Input-Phono

[Install]
WantedBy=multi-user.target

And in the setup_amp script, I have:

#!/bin/sh

sleep 4s
irsend SEND_ONCE NAD_SR712 KEY_SLEEP
sleep 4s
irsend SEND_ONCE NAD_SR712 Input-Aux
sleep 4s
irsend SEND_ONCE NAD_SR712 Input-Aux
sleep 8s
irsend SEND_ONCE NAD_SR712 Input-Aux

As you can see, some fiddling with timing (and retrying) is prudent. And it works!

Dragons of Spring Dawning (1985) ★★★☆☆ #books

🕤︎ - 2021-07-12

I finished volume 3 of the Dragon Lance Chronicles trilogy, Dragons of Spring Dawning, recently - after reading volume 2 some time ago.

The last book of the trilogy continues in the same style as the second - it reads like an epic AD&D-session. It's fun, varied and full of clichés, some of course aimed at your tear ducts - and it finishes the storyline in an appropriately grand way.

★★★☆☆

This one also says $3.50 on the cover - no Danish price sticker, and no notes from when I read it the first time on the pages.

Lille langebro

Today

Christian Schlüter (37).

Tomorrow

Annemette Seistrup (59).

Monday

GNU (38).

Google (23).

Wednesday

DASK ran first program (64).

Thursday

James Dean crash (66).

Kippers in the Jungle (21).

Kippers on the Rocks (1).