I'm making a PipeWire matrix mixer

Once in a while, you get an idea for something to build that completely takes over your brain and you can't stop thinking about it.

This one scratches an actual itch I have with my music gear. I believe I have all the pieces of the puzzle, I just need to put it together in the correct way. It's a perfect mix of doing things I'm comfortable with and pushing me into unusual territories.

The Erica Synths Matrix Mixer and Conductive Labs MRCC have been on my wish list for a long time. I'd really like to have these, or something similar, that allows for flexible routing of audio and MIDI.

I have a Bitwig template that takes me a very long way there. But I keep falling into the trap of endless possibilities in DAWs when I open Bitwig. So I'd like to be able to route things around without it.

I have a Soundcraft Signature 12 MTK which gives me a lot of flexibility with regards to sending audio back and forth from/to the computer, but it's huge and doesn't fit into a portable setup that can be thrown into a backpack and taken anywhere. I've also been thinking about getting a 1010music Bluebox because of the portability.

No matter what mixing/routing hardware I have been looking at, I have been seeing limitations. Maybe apart from the Erica Synths Matrix Mixer and the MRCC. But even those have a finite amount of inputs and outputs and are the MRCC is definitely not very portable.

A lot of my gear has USB audio/MIDI. And with PipeWire it's technically super easy to route things around in any way I'd like. I'm generally really impressed with how easy USB audio is on Linux with PipeWire, compared to the horror stories I read of hoops to jump through to get the same results on Windows and Mac. I just didn't find any software on top of PipeWire that solved this issue in a way suiting me.

A few days ago, I had a look at the CLI tools provided by PipeWire and then I realised that making an interface on top of these could give me the matrix mixer I have been dreaming of. The only downside is that it requires a computer to be part of the solution. But it can be a laptop or (probably) even a single-board computer. I can live with that. The huge upside is that if I'm running out of inputs or outputs, I can just add more.

I have a bunch of ideas that will really improve the daily quality of life. From the top of my head:

• Basic routing of both audio and MIDI.
• Pairing of audio channels for routing around stereo audio (an maybe even beyond just stereo).
• Saving/loading presets that will automatically link certain devices when they are connected to the computer.
• MIDI control of the matrix mixer:
  • Toggle links.
  • Change presets.
• Virtual devices that allows routing outputs back into the matrix.

And further down the line, maybe allow attenuation of links and even hooking audio plugins in somehow.

Rødbeder

Rødbeder. Sjældent der hvor man ser dem eller har dem og tænker "Wow, mega lækkert", hva? FORKERT! I hvert fald efter du har prøvet følgende:

Skær dem i grove tern/stænger, ikke for tykke. Sammen med nogle løg i kvarte, lagene pillet fra hinanden. Og en håndfuld fed hvidløg i ca. halve. Salt, peber, en sjat olie. Vend det hele rundt i et fad, og så i ovnen ved 180 grader. Hver ca. 20-30. minut skal de lige ud og væltes rundt i fadet.

Det virker håbløst i lang tid. Og ligner noget kantinen har fundet på da de skulle rydde op bagerst i fadeburet. Men når det nærmer sig et par timer i ovnen, starter transformationen. Det hele begynder for alvor at skrumpe ind og blive rynket og branket og spændende. Prikken over i'et er at du lige smuldrer noget blå ost ud over når det er så godt som færdigt og lader det smelte ud i blandingen.

Og så spiser man det vel bare, tænker du. Og det kan du godt. Og det er lækkert. Men du kan også putte det i en bøtte og gemme det til næste dag. For det smager dobbelt så godt når det er koldt!

Velbekomme.

Impending home server hardware replacement

For a long time, my home server has been a Dell XPS 15 9530 I "borrowed" from the laptop graveyard at a previous job. My important data is stored on 2 mirrored disks that sit in a cheap USB bay attached to the laptop.

Fellow self hosters from data.coop laughed at me when I told them about this setup, but it has served me well for more than 5 years. And I think repurposing an old laptop for this has several benefits:

• Used laptops are everywhere. And easy to get your hands on, if you don't already have one in your drawer.
• It adds more years to the life of a laptop that might otherwise have been turned into a dust collector or e-waste.
• It's a small, self contained package with all you need (except an ethernet port, for which I use a dongle).
• If it even has a functioning battery (mine doesn't), it has built-in backup power in case of disruptions.

A few days ago when I got home from a concert, I was met with the surprise nobody likes as a server administrator: What looked like some sort of disk failure. at least the root file system had turned read-only. It was late, so I decided to make a copy of the syslog to another computer and turn the server off over the night. Knowing that solving this could easily take several hours and doing that kind of work during the night is no good.

Next morning I turned it on again and it booted into initramfs. I looked at the syslog copy and found some lines indicating what the problem was:

Nov 25 22:15:23 longtail kernel: [1506099.480485] Aborting journal on device sda2-8.
Nov 25 22:15:23 longtail kernel: [1506099.484147] EXT4-fs error (device sda2): ext4_journal_check_start:83: comm rs:main Q:Reg: Detected aborted journal
Nov 25 22:15:23 longtail kernel: [1506099.484190] EXT4-fs error (device sda2): ext4_journal_check_start:83: comm systemd-journal: Detected aborted journal
Nov 25 22:15:23 longtail kernel: [1506099.486302] EXT4-fs (sda2): Remounting filesystem read-only

While I wasn't able to find out why this has happened, I learned that I could simply run fsck /dev/sda2, let it fix my issues and then reboot back into Ubuntu. What a relief! What I worried would be a full day operation turned out to take less than half an hour.

But this laptop is more than 10 years old. I already started thinking it was about time to replace it, in order to not run into trouble with worn out hardware. This is probably the first warning that I should definitely do that.

Good thing is my previous laptop, a Dell XPS 15 9530 which is only 5 years old, has been sitting on a shelf for a long time, waiting to take over.

BIOS update of a Dell Linux laptop without a battery

My previous laptop, a Dell XPS 15 9560, had a weird BIOS issue. When turning it on, it went into some sort of self diagnosis mode if I didn't intervene and explicitly told it to boot from the SSD.

I found a new use for the laptop, so I decided to try and flash a BIOS update onto it, hoping it would solve the issue. Which turned out to be harder than it should.

First of all, BIOS updates come as Windows .exe files. But I don't run Windows. Alright. When turning on the computer, you can press F12 to enter the Boot Options menu. From here, theres an item called BIOS Flash Update.

This starts a small utility that will do the BIOS update flashing if you plug in a USB stick with the .exe file on it. But this only only works if the laptop has a battery with a certain charge installed in it. And mine doesn't, as the battery stopped working a while ago, so I completely removed the battery. If no sufficiently charged battery is found, the BIOS udate is blocked by a message saying:

PowerStatus: Inadequate

Searching the interwebs led me to various "solutions" that all turned out to not work. One involved making a bootable FreeDOS USB stick with the .exe file on it, to execute it from there. Trying this gave me another error:

This program cannot be run in DOS mode

Another proposed solution was to hold down Esc and Ctrl keys while turning on the computer with a USB stick inserted with the .exe on it. This just brought me to the same self diagnostics thing that I was trying to avoid.

Some places said that adding a /forceit argument (and other similar arguments) when running the .exe in Windows would bypass the battery check. But I still wasn't running Windows.

I finally found out that these arguments can be entered in the Options textarea in the BIOS Flash Update utility.

So, the solution turned out to be:

• Put the BIOS update .exe file on a FAT formatted USB stick and insert this into the laptop.
• Press F12 when the computer is starting, in order to reach the Boot Options menu.
• Select BIOS Flash Update.
• Find and select the .exe file via the ... button.
• Enter /forceit into the Options field.
• The PowerStatus value should shortly after change from the red Inadequate to a green Forced.
• Press the Begin Flash Update button to initiate the flashing.

This will probably also work on other Dell laptops with a similar BIOS setup. Make sure to keep the power supply plugged in during this, as there is no battery to help you i case the power plug is removed.