Introduction

So, ehm. I have very random interests, and now I just play around with SIM cards a bit.
So 6 months or so ago I bought Czech T-Mobile Twist IoT Standard SIM, just for fun. There were instructions on how to activate it from abroad, and it worked. Better yet, it can connect to 3 MNOs in Slovakia.

Cool. But I've advanced. I've found about these external eUICC chips like ThinkPad Thales. In the end I got 9esim V3. Also has STK profile switching.

I wanted to also convert that T-Mobile IoT card to eSIM, but failed to do so. Profile downloaded and installed just fine, but the SIM wouldn't connect. T-Mobile's website says it may not be possible to activate eSIM in Roaming in some cases, and to rather do so in Czech Republic.

Now, you see, I am a totally normal, sane and reasonable person. So I figured out my only option was to ~~give up~~ travel to Czech Republic.

Unfortunately I don't live near the borders, so this took a while.

Attempt and result

I arrived in Olomouc. If I were to get stuck somewhere, it better be some normal city rather than a small town or village.

I've had 2 of those SIMs to try 2 slightly different ways since I am not sure if it makes a difference.

1. I downloaded eSIM profile in Slovakia
2. I downloaded eSIM profile in Czech Republic

Neither worked.
Relevant screenshots:

Theories:

1. There's some difference between eSIM adapters and native eSIM that breaks functionality in this case
2. IoT cards can't be converted to eSIM. They are also sold as physical cards exclusively, but then why can I generate the activation code?

Other issues on the journey

My carrier 4ka barely ever managed to connect in roaming. It would take minutes to register at least in 2G which it would take again if it disconnected. It also wiped the correct APN which I had to manually add back. 4G it managed to connect to twice for a short time.
It also had issues registering in home network back in Slovakia. I had to switch it to 2G only first, and just then back to 4G in *#*#4636#*#* menu.

But anyway, my data plan doesn't have any data allowance in EU, just €0.014/MB.
So I just bought BNESIM.

I also had some issues with anxiety until I was finally on train to CR. I couldn't stop my leg, I was a bit shaky, and when I checked my HR was 117BPM while just sitting. Not that high, but still a bit too high for resting HR.
79BPM on the final train.

Photos

Also found this "vehicle for measuring of RF networks", but unfortunately it was locked away from me, so I just have this bad photo:

Cat

It was in the Púchov station back in SK. Just heard a loud meow when I was waiting for a train back home and walking around the station.

End

Not sure what to do now. I wanted my primary SIM as physical one in slot 1 and random eSIMs in slot 2, including this one. Crap.

Sticker's fine, somehow, and already on my ThinkPad. Unfortunately I only got 1, and sc07.shop seems to be down. Oh well.

Where the hell was that envelope stuck...

Who needs sleep anyway?

Edit: Replaced Catbox with Imgur as it didn't embed

There's an expectation that you can receive calls anytime, reply to messages quickly, it's like having people in your pocket, always with you.

And I don't even use most social media, which others often find weird. I don't understand how people put up with and manage so many messages when it's multiple per minute. Snapchat, Instagram, Discord, Messenger, every few seconds responding to something is what I see most others doing.

Oh, funnily, it's often the people who constantly say "Back in my good ole times we had no smartphones like you, and we lived just fine." who expect a prompt reply, or get mad when you don't pick up the phone.

People can and will just message you during the day and suddenly expect you to change your plans.

And why have a smartphone then? Its evolved from being just a communicator. It's a computer, flashlight, camera, modem, access point, storage device, music player, radio receiver, remote control, portable server if you're weird enough, but simply, a lot more than just a messaging and calling device.

I can at least trash the calling part and excuse it on technical difficulties (disabling VoLTE, VoWIFI, VoNR and fallback 2G/3G networks).

I just hate the feeling that someone could suddenly message me. I hate having to pull out my phone because a message has arrived and I have to respond. I hate having to look at it every few seconds when I am trying to do something else, because someone messaged me.

I regret showing RCS to my father. I didn't realize just how much good the monetary cost of SMS was doing. "Free" messaging is paid by the soul.

Device: Ulefone Armor 24 (cheap-ish Chinese brand)

The default audio quality is absolutely awful. It's like this everywhere, including the default camera app.
The issue shows up with external microphone as well.

Basically it sounds like over-compressed audio that gets easily beaten with 22.5kHz 64kbps MP3 (comparing to what I listened to recently).

I've found this audio recorder app that allows selecting audio source manually, including "unprocessed" audio: https://gitlab.com/axet/android-audio-recorder
The result is far better.

Audio recording samples

I just recorded music playing from my laptop, so yeah, the audio source isn't that great either, but you can hear the artifacts there.
Both were recorded lossless.

Default

https://files.catbox.moe/e33ufc.wav [2.7MiB]

https://files.catbox.moe/d2n7sg.flac [1.4MiB] - converted to FLAC for in-browser playback

Unprocessed

https://files.catbox.moe/xf9ab8.flac [2MiB]

Basically, it's just missing some noise-cancelling, but other than that, it's far better.

I don't care if disabling that potentially screws up phone calls, I don't like those anyway.

Couldn't find the answer online and spent unnecessary hours trying to solve it, so I'll plop the answer here.

Problem

Software like SDR++ can't find any devices
systemctl status sdrplay shows following errors/warnings:

[3943]: sdrplay_apiService: UpdateDevicesL: ERROR: libusb_claim_interface() -6
[3943]: sdrplay_apiService: sdrplay_apiServiceWorkerThread: ERROR: UpdateDevices() failed 1
libusb: warning [libusb_exit] device 1.5 still referenced
libusb: warning [libusb_exit] device 1.1 still referenced
libusb: warning [libusb_exit] application left some devices open

Based on what I found, -6 corresponds to LIBUSB_ERROR_BUSY. The device has been claimed by something else.

Specific problem

I found this blog post on using RSP1 clone without the proprietary software: https://blog.marxy.org/2023/05/using-sdrplay-rsp1-clone-with-cubicsdr.html
It mentions blocklisting some kernel modules which capture the device.
Comparing lsmod | grep msi with known good system (Arch Linux), sure enough, these aren't loaded while in Linux Mint they are:

msi001                 20480  1
msi2500                36864  0
videobuf2_vmalloc      20480  1 msi2500
videobuf2_v4l2         36864  1 msi2500
videodev              352256  3 videobuf2_v4l2,msi001,msi2500
videobuf2_common       81920  4 videobuf2_vmalloc,videobuf2_v4l2,msi2500,videobuf2_memops

Solution

Add the following lines to /etc/modprobe.d/blacklist.conf to blacklist these kernel modules:

blacklist msi001
blacklist msi2500

And reboot.

Personal note/rant

I spent so much time... I tried different API versions, so I also had to uninstall the newer ones which with this stupid software can only be done with careful manual removal of files.
I tried different USB ports (just in case), reinstalling SDR++, SoapySDR, installing some other potentially interesting looking libusb related packages, trying to find at least one other person with this issue...

And in the end it's just interfering kernel modules like with RTL-SDR.
Well, if this gets indexed the solution should be easy to find based on the error now.

Image source: https://www.telepolis.pl/tech/sprzet/ulefone-armor-34-pro-armor-33-pro-armor-mini-4-mwc-2025

Just another ridiculous device from Ulefone.
Unfortunately, I can only find its dimensions, but not weight. The thickness is whopping 3.4 cm (1.34 inch).

Currently I own a smaller one, Armor 24, which is still 2.75 cm (1.08 inch), but even that weights 647g (1.43 lbs).

I wonder if these brands like Ulefone, Doogee, Unihertz will reach the 1kg mark at some point.

Be ready to dial 911 if it falls on your face.

Edit: Found answer here: https://groups.google.com/g/tigervnc-users/c/c4mihwmz_bI
Apparently only local sessions have access to certain HW. Audio devices are also in group audio, so I added my main user to that. Might be the fix for other stuff if I figure out the exact issues.

So I have a Mini PC running Linux Mint (headless) that I want to (sometimes) access over VNC remotely.

Using just TigerVNC has issues. First, XFCE got reset to its defaults. I don't mind this too much. There are some password prompts and all power options other than "Log Out" are inaccessible (DBus seems to be running if that's related. But also, more just annoying than an issue.)

The biggest problem is with audio. There appear to be no audio devices with aplay -l when run as regular user, but they do show up for root.
I tried running a session as root, but...
User
Root
I don't even get the Dummy Output.
It seems to have a problem with connecting to PipeWire (maybe because root can't use DBus? (just a guess, remembering errors of some apps when run as root))

So that's what happens before logging in with LightDM.

If I do login in GUI, things will magically work

(The Mint customization stays broken after it happens once)

So I am guessing some more stuff is started when using LightDM, and I'd like to know what exactly it is, to reproduce it.

As for why not keep using autologin:

1. I don't want a GUI session running when unnecessary
2. x11vnc is somehow extremely slow compared to tigervnc even with same compression, quality and resolution

Thanks.

There goes me using laptop as a monitor.