Useful Consumer Review

I walk a lot, and I used to listen to music while walking, using big, beefy, good wireless headphones or headphones with an mp3 player built in. That’s a solved problem; excellent products exist.

Last year I started listening to radio dramas instead. Mostly mysteries, and quite a lot of stuff from the 50s. It’s fun! But I don’t need a full set of headphones to listen to that stuff; it’s fine listening to in mono in one ear only.

And here my troubles began.

There’s quite a lot of wireless earbuds out there, but they all have the same problem: The range sucks.

The first one of these I tried was the original Earin, and it was pretty much unusable. But now there’s the Earin M-2, which promises to have solved all the problems.

Like the previous version, it comes with a round charging case…

… and both buds fit in there. The charging case is larger than the previous version, but it’s also a lot less fiddly. The buds slide in there like magic (probably magnets), and that’s nice.

And the buds themselves are also larger, and don’t look as cool as the M-1s.

The range is better than the M-1, but it’s not actually good. The frustrating thing when reading reviews about wireless headgear is that apparently nobody who reviews them uses them outdoors. Indoors, blutooth works well, because it can bounce the radio against the walls, but outdoors, there’s nothing, so the radio just dissipates unless it’s very powerful.

If I have my phone in my left front pocket and an earbud in my right ear, they’ll drop connection like crazy when outdoors. I have to put the phone on the same side of the body as the earbud is if it’s to have any chance of working semi-reliably.

So these are pretty much standard in the range dept… but the UX is horrible. Just horrible. They use a touch interface, and give no audible feedback. So the way to use them is to put one in an ear, wait for ten seconds and then hopefully it’ll have contacted the phone, and then tap it to unpause, and then nothing happens, and then tap again, and then again, and then you’ve tapped too many times and it unpaused and paused again.

And when you’re not using it, you can’t just put it in a pocket, because if you touch it, you turn it on and it’ll use all its battery while not doing anything.

So you have to carry the case around with you, which is a bother.

Compare the Earin M-2 disaster to this older, cheaper earbud that goes under many names, like Savfy and Rowkin Mini. They look slightly different depending on who the manufacturer is, but it’s the same product, I think.

See that thing there on the side? It’s a button. B-u-t-t-o-n. Button. You press it to switch the earbud on, an you press it again to pause/unpause the audio, and you long press it to switch it off. When the earbud connects to the phone, you hear a voice saying “connected”. When it switches off, it tells you that, too.

The UX is hard to improve on.

Of course, the range is horrible, just like the Earin M-2. Perhaps even worse, really: I frequently find myself putting my phone in my shirt pocket to have it stay connected if I do something crazy, like look around before crossing a street.

Perhaps somebody one day will make something better, but it hasn’t happened yet. I hope that someday somebody will realise that playing audio using an almost unbuffered wireless stream is absurd: The earbuds should instead pull down blocks of data from the device and then play it. That would also allow it to shut down its antenna, meaning power savings.

Of course, this won’t work for real-time audio (like talking on the phone) but does that even happen any more? 100% of my use case for these devices is listening to prerecorded data, so it’s not like it has to be ultra low latency or anything.

ANYWAY! I’m mostly listening to mystery radio dramas, and the challenge there is that the actors will alternatively shout “THERE”S THAT BAD GUY! STOP HIM! PEW PEW!” and whisper “ssssh here’s the solution to the mystery that I’m telling you while we’re in this hedge”, and I found myself having to turn the volume up and down a lot, which is totally annoying. Surely there’s a solution to this?

And of course, and it’s called “compression” or “normalisation” (even if those aren’t the same things). On Linux, sox is a fine program that can do many audio things, and it has a module called “compand” which is made to compress audio (i.e., make the loud parts less loud and the quiet parts louder). By Googling a lot and experimenting a bit, I found some settings that work well for radio theatre, and I wrote a little bash script that’ll take a tree of mp3s, normalise/compress the audio, and then write out new mp3s, and also copy over id3 tags and artwork and the like.

It’s a trivial script, but Googling all the moving parts took me a while, so it’s here all put together in one place so that you don’t have to do this work yourself if you find yourself in the same position and landed on this page through googling “audio compression no I’m not talking about file size compression but, like, compression of the audio range, dude”.

I’m guessing this will also work on podcasts and the like, although I would imagine that the audio range is much narrower there to begin with. I’ve been using this for a few months and it seems to work well, although sometimes some very quiet sounds do get amplified a bit much.

Useful Consumer Review

When buying electronics, the range of products available is vastly superior in the US compared to any European country. Fortunately, power adapters are now almost all “universal”; that is, they accept 110V-230V. So the only problem is the physical interface.

I’ve been using these teensy adapters for a while, but the problem is…

.. that they’re extremely rickety. They neither have a solid grip on the Euro side, and the US side isn’t satisfactory, either, so it just feel… bad.

So I went looking for other variations, and I found these somewhere in Europe. They are totes unrickety, but they’re huge. For something that does nothing but accept one plug and plug into another plug (there’s no voltage adaptering), is silly. So the other day I wondered… surely something smaller has to exist? I mean, something that’s just flush with the Euro “Schuko” plug? I mean, it should fit in there? Why doesn’t it exist?

Behold! It does exist!

It’s not totally flush, which is weird, because the US plug is shallower than the Euro er hole, but still, not. But it’s almost there! And the grip on both ends is very satisfactory. Nothing rickety about these.

They’re called “OREI American USA To European Schuko Germany Plug Adapters CE Certified Heavy Duty” *phew* and they’re about $1 each.

And they’ve been working for several hours now, so they must be perfect.

You have to wonder what the people who made that huge adapter were thinking… “This will do”? No, it won’t.

Everything Dies

Gah! I had the almost perfect machine for schlepping around the apt while cleaning, and then it goes and does this:

Rebooting seems to help… sometimes. One out of five reboots it seems to come up alright again, but if I flip the orientation it goes back to that state again.

It’s an HP Spectre x360, according to dmidecode… Anybody know what’s up with this? Loose wires? Firmware updates? GPU settings?

I imagine there is a setting in the nvidia configuration utility: “[ ] Don’t shake the screen like you just don’t care” and I just have to tick that.

Right? Right?


Perhaps I should start looking for a new laptop…

Useful Consumer Review

Some weeks ago I bought this Levimoon lamp. I didn’t really think it was going to work or anything, but hey:

Unfortunately, despite being totally cool and fun, it makes a “BzbbbzbbzzHhghghzzbz” sound after it’s been switched on for about two minutes, so it’s a crapgadget instead of a useful lamp.

And getting the moon to levitate (it’s done with electromagnets) can take a few tries, but I think I’ve got the hang of it now. Instead of taking a minute to get it to the right position, it only takes me ten seconds now. If I’m lucky.

But I can’t believe that I’m complaining about a hovering moon lamp not being perfect. It’s a hovering moon lamp!

Only useless!

Oh well. Perhaps the next iteration will be silent and you can actually have it switched on.

Fast Music, or: USB Is Weird

I have my music on an USB3 RAID5 consisting of three external disks connected to one of these, which isn’t a bad little computer: It’s has a 1.7GHz i7-3517UE (Ivy Bridge) CPU, so it’s small, but not horribly slow.

But then one of the disks went AWOL and I thought that perhaps it was time to upgrade the disk array. It’s about seven years old, after all, and surely things have gotten better in the meantime.

My main use case, is, well, it’s a file server that I play music off of:

That’s not a very strenuous task: It basically has to feed out FLAC files over NFS faster than my stereo machine (pictured above) can play them, and basically no machine made after 1987 is too slow for that task.

But my Emacs-based music player doesn’t do any caching of metadata, so if I ask it “show me all the 8K records I have in chronological order”, it has to read eight thousand files, and that takes a while if the disk is slow. This is a problem that has grown year by year, of course, so it’s another reason to explore faster disks.

(I mean, I could add a caching system to my music system, but to quote what Leonard Nimoy said in The Empire Strikes Back: “Meh.”)

So I got a couple of USB3 SSDs. Splurge! I connected them up to the Intense PC and started copying things over. I wondered how slow the original RAID was, and it turned out to be 50MB/s, which is very slow, indeed. With the new disks, I should get like, er, more! MORE!

Copying finished, I did indeed get higher speed. 100MB/s. Which is pitiful. The native speed of the SSD should be 500MB/s, but given USB3, it should be slower, but not 20% of the speed.

So after much head-scratching, I noticed that the CPU was pegged to 100% whenever I read intensively from the disks. Is it possible that USB is such a crappy system that a 1.7GHz Xeon CPU from some years ago would be the bottleneck here?

So I extended a USB3 cable to the other server I had in the same closet, which I had bought a month earlier to do the RAID for my film collection:

It has a i5-7260U CPU @ 2.20GHz, so not much difference in Hurtzes, but it’s a 7th gen Intel CPU, and the other machine has a 3rd gen.

And… Wow! 320MB/s reading speed! 3x faster than the older machine, with the same SSDs, USB3 hub and everything.

I quickly rejuggled my setup and made that machine do the /music array, too, and sighed a breath of relief.

Now I can play music six times faster than before! Whoho!

But then!

The RAID went AWOL, always with the same messages about “tag#0 FAILED”, “USB disconnect” and “I/O error” on various /dev/sdx-es.

I first suspected the USB3 hub, so I got a new one… A couple of days later, the same thing. Tried a different USB3 cable (it’s always the cable!); same thing.

Of course, after each time this happens I have to rebuild the RAID, things get inconsistent and stuff.

Finally, I move the USB from the port on the left there to the right…

And two weeks later, still haven’t had a single disk brown-out.

So: The takeaway here is: 1) USB is a janky thing. It’s not quite like SCSI in olden days (no goat sacrifices needed), but it’s janky. 2) If your USB is slow, get a faster CPU.

The good thing about USB setups like this is that, in my experience, once you get them going satisfactorily, they’re pretty stable. Unless you do something crazy like insert a new USB device. Then all bets are off.

Of course, having a machine with room for plenty of SATA disks internally would be better, but I’ve never seen one that’s a) small and IV) allows easy access to disks that have failed and have to be replaced.

But look!

I can now display all the albums from 1975 by the snap of your fingers! If your fingers snap really slowly. But still!

And since the /dvd disks spin down automatically, my computer setup is now 100% without anything mechanical moving around normally, and I can walk past that closet without hearing any humming sounds.

Well, beyond my tinnitus, that is.

The Ever-Shifting Sands of udev.rules

I use Telldus Tellstick to do home automation *cough* I mean control the lights:

It’s an unassuming USB stick that implements a serial interface so that you can talk to it by just sending some strings to it and read the response. Ideal for Linux! Yes!


You do want the device to show up at a default space so that you can find it, and if you have more than one serial USB interface thing, which one of /dev/ttyUSB0, /dev/ttyUSB1 og /dev/ttyUSB2 is it?

udev to the rescue!

And here your woes begin, because every fucking time you upgrade Linux, the fucking udev people change the fucking syntax vaguely and how you fucking refer to fucking devices. Fucking.

In the really olden days you said

KERNEL=="ttyUSB*", SYSFS{idVendor}=="1781", SYSFS{idProduct}=="0c31", 
  MODE="0666", NAME="tellstick"

But then they changed SYSFS to ATTR in the slightly less olden days:

KERNEL=="ttyUSB*", ATTR{idVendor}=="1781", ATTR{idProduct}=="0c31", 
  MODE="0666", NAME="tellstick"

Then they disallowed renaming devices, and instead you add symbolic links to the device:

KERNEL=="ttyUSB*", ATTR{idVendor}=="1781", ATTR{idProduct}=="0c31", 
  MODE="0666", SYMLINK+="tellstick"

Then they changed ATTR to ATTRS:

ATTRS{idVendor}=="1781", ATTRS{idProduct}=="0c31", MODE="0666",

Then they changed what the attributes refer to, so instead of getting this:

[larsi@stories ~]$ ls -l /dev/tellstick 
blrwxrwxrwx 1 root root 7 Feb 25 16:12 /dev/tellstick -> ttyUSB1

you get this:

root@stories:/home/larsi# ls -l /dev/tellstick 
lrwxrwxrwx 1 root root 15 Feb 25 16:27 /dev/tellstick -> bus/usb/001/014

And that doesn’t work, because that’s not a serial USB interface, but a raw USB interface of some kind which can’t be opened like a serial interface.

And, remember, you can’t refer to /dev/ttyUSB*, because that’s the problem you’re trying to solve.

The solution to these problems is this following command:

 # udevadm info -a -n /dev/ttyUSB1

You’ll get output like

 looking at device '/devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10:1.0/ttyUSB1/tty/ttyUSB1':

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10:1.0/ttyUSB1':

Well, nothing there to distinguish the Tellstick from anything else, to continue down the output…

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10:1.0':
    ATTRS{bAlternateSetting}==" 0"

Yes! The ATTRS{interface}==”TellStick” thing looks like it’s something we can use to distinguish between Tellsticks and other devices, and it’s not so far down in the device hierarchy that we’re not talking about serial interfaces any more, and presto!

[larsi@stories ~]$ ls -l /dev/tellstick 
lrwxrwxrwx 1 root root 7 Feb 25 16:33 /dev/tellstick -> ttyUSB1

Here’s the magical setup file, for reference if anybody wants to write a udev rule for Tellstick devices that works on February 26th 2018, but probably not the week after:

$ cat /etc/udev/rules.d/10-tellstick.rules 
ATTRS{interface}=="TellStick", MODE="0666", SYMLINK+="tellstick"

You can also refer to the parent attributes by saying SUBSYSTEMS at a strategic point, so the following also works today:

KERNEL=="ttyUSB[0-9]*", SUBSYSTEM=="tty", 
  SUBSYSTEMS=="usb", ATTRS{idVendor}=="1781", 
  MODE="0666", SYMLINK+="tellstick"

Basically, when upgrading a Linux machine, most everything just works; all the peripherals and all the software. But I always end up twiddling the udev setup for half an hour.

Useful Consumer Review

I’ve had the vast majority of the lights in my apt. controlled remotely (from Emacs, of course) for like a decade. It’s a flexible system built on Telldus Telstick receivers and transmitters, and Nexa wall sockets.

But… Look at the un-pretty:

Yes, those outlets are fugly. Fortunately quite a few of them are hidden behind furniture, but I’ve been on the lookout for prettier solutions. Remote-controlled light bulbs are nice, but most of them use proprietary control systems that seem fiddly and not easy to integrate into my setup. Ikea have released bulbs that show some promise, but the form factors are still very limited, so I’ve been biding my time for years waiting for somebody to make something… better.


Telldus apparently started making these outlets a couple of years ago. They use the same 433MHz signalling system as the Nexa outlets (and the Telldus transmitters), and they look so much prettier. Of course, Telldus seems to be phasing them out already because they want to sell a completely new product line based on ZWave, so these were on half price sale and I snapped up a stack of them.

Sometimes it pays to be oblivious.

So last night I sat down to start changing the outlets, and the first thing to do is to program them. (I give each outlet an individual code, a room code, and an apt. code, so that I can switch the entire room/apt on/off with one signal.)

But they behaved very strangely. One of the outlets I could give code 40, but not 202. But I could give it code 56. Hm. 7 bit problems? No, I could give it code 153… WTF?

So I started dumping the output from the included remote controls:

And it dawned on me that the second-to-last hex digit was always 9 on the included remote controls, but not in the codes I transmitted.

What I had was

(when (> unit 16) 
  (setq house (+ house (/ unit 16)) 
        unit (mod unit 16)))

That is, I did modulo 16 on the unit code (because that’s a 4 bit value) and then went to the next house code. And that worked fine for the Nexa outlets, but with these Telldus outlets, not all house codes are valid. I didn’t investigate in depth what patterns were allowed, but every 16 was definitely allowed, so I changed the above code to:

(setq house (+ house (* (/ unit 16) 16)) 
      unit (mod unit 16)))

So I skip to the next sixteenth house code instead of the next one.

And then it works! Of course, that means that I had to reprogram all of the outlets, even the old Nexa ones that I didn’t swap out. Oh, the tangled twisty turns of life.

Look teh pretties:

They seem to have pretty good reception, too. That is, at least not any worse than the Nexa outlets. But as you can see, they’re not perfect: They’re juuust a smidgen too wide to fit two side-by-side into a standard outlet, and they may even be problematic with a fat non-remote neighbour.


But prettier!  And more convenient.  These Telldus outlets have a manual on/off button, so you can get the lamps to switch on/off even if the control system is down, for some reason or other.

Now I just have to decide what to do with the old outlets… Probably not much use for them, but perhaps I should hold on to them to see whether the Telldus outlets continue for function well.