Henrik Carlsson's Blog

All things me.

More progress on the music player for the kids

posted this note on and tagged it with The Kid's Music Player ΠiFi Music Player

Slightly simplified the music player for the kids has two jobs:

  1. Scan for QR codes using the camera and identify the ones that contains a Spotify URI (using zbarcam) and
  2. send that URI to the MPD that plays the music from Spotify.

At the moment I am able to set up separate tests for the two jobs and both works, on there own. The problem is that I’m currently not able to set up MPD with Spotify and the zbar tools at the same time. It seems to have something to do with different operating systems and/or other kinds of conflicting requirements that I need to lock into.

For the tests right now, I use standard Raspbian plus zbar for bullet point number one and Pi MusicBox for point number two.

For my own memories sake, this is the very simple (and probably quite brittle) shell script that I’m using for bullet point 1:

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A music player for the kids

posted this note on and tagged it with The Kid's Music Player ΠiFi Music Player

My kids, Iris and Ebbe, are four and a half, and two years old respectively. Both of them loves to listen to music and dance. Compared to when I was a kid they have access to tremendous amounts of music. If I wanted to listen to a song as a child, I had to have it on a cassette or later in life a cd. Today’s kids have access to ”all the world’s music” in Spotify, Apple Music or similar.1

The problem with the modern world in this regard is that a cassette deck and a box of cassettes is much more kid friendly than a smart device like a phone or tablet with Spotify and possibly also a smart speaker connected via bluetooth, AirPlay or a Chromecast.

Spotify has a nice solution for this in there Spotify Codes. It wouldn’t be to hard to make a whole box of cards, one for each album and/or playlist that the kids want, and teach them how to scan the cards with Spotify. The problem is that it requires them to use their iPad (or my phone, or their mother’s phone).

Why is that a problem? Because if they use the iPad they will undoubtable be sidetracked by YouTube or something similar. Sometimes having them watching videos is great. I’m certain that the reason Iris know quite a few words in English, despite being a Swede with Swedish parents, is that she’s watched a lot of English videos on YouTube. But sometimes I want them to just listen to music and not having to have a discussion about why they are allowed to use the iPad but not the apps they want.

So I’ve started toying with the idea of building them a music player that works as simple or simpler than Spotify Codes but that is a dedicated hardware device, a Raspberry Pi. The plan is for it to use either QR codes or NFC tags to control what is being played, so that way the kids can have a box of cards with artwork, similar to the box of cassettes that I had as a kid.

I think it will work.

Right now I’m going to test various setups for it and document my progress here on the blog, under the tag The Kid’s Music Player.

Some links to similar projects


  1. Yes, I am being Captain Obvious here, I know. 

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Strömstad 2019

posted this note on and tagged it with Strömstad 2019

Linn och jag är för närvarande i Strömstad, på en semesterresa utan barnen. Ebbe är hos Linns föräldrar och Iris hos min mamma.

Varken Linn eller jag har varit i Strömstad förut. Linn har heller aldrig varit på västkusten förut, undantaget Göteborg och för min del har västkusten mestadels varit synonym med Hunnebostrand. Så därför hamnade vi här, helt enkelt för att ingen av oss varit här förut.

Vi passade på som en del i vår Arvikaresa, så att vi kunde lämna bort barnen några dagar och åka själva. Det är sällan vi kommer iväg på saker utan barnen, så när det väl blir av är det jätteskönt. Tanken var från början att boka ett spahotell här men vi var för sega med att bestämma allt, så när vi väl fick tummen ur så var det fullbokat. Därför hamnade vi på Strömstad Camping, ett äventyr i sig eftersom jag inte varit på en camping sen jag var barn och Linn aldrig har campat. Hur som helst så bokade vi en stuga och det är där jag nu sitter och skrivet det här.

Idag har vi gjort själva resan hit från Arvika och sen har vi flanerat på ett shoppingcenter innan vi åkte till campingen. Sen satt vi länge på altanen i solen och drack vin, prosecco och öl och åt chips innan vi slutligen gick on mot Strömstads centrum, promenade bland pirerna och åt middag på The Dubliner at Skagerack. God mat och väldigt mysigt läge!

Under resans gång har jag meckat lite med att posta platsinformation tillsammans med bilder, så därför har det blivit lite extra blogginlägg vilket är kul. Exakt hur jag ska använda platsinformationen på sikt vet jag inte men det är kul att ha det sparat, särskilt när vi är på nya ställen som nu.

Jag försöker även tagga alla inlägg härifrån med Strömstad 2019.

I’m back using Alfred

posted this note on and tagged it with Productivity

I don’t know exactly when it happened, but it was probably some time when I re-installed a computer or set up a new one that I decided to not install Alfred and instead try to get by using just Spotlight.

As far as I could tell it wasn’t a big downgrade, and it saved me one step in setting up a new computer. A few days ago though, I decided to try Alfred again and OH MY GOD.

While going from Alfred to Spotlight didn’t feel like a big downgrade, going from Spotlight to Alfred seems like one of the biggest upgrades ever.

So Alfred, I’m back. Sorry I ever left!

Spider-Man: Homecoming

posted this note on and tagged it with MCU Movies

🎞 Watched: Spider-Man: Homecoming

This was exactly the kind of movie that I needed to watch right now. Light-hearted and very entertaining. I’d probably say it’s my favourite MCU movie so far. I loved the acting, the way Peter was characterised, the way the classical characters where changed and modernised. I loved the whole thing. Also, the sort-of twist with the identity of The Vulture took me completely by surprise.

My only complaint is that the action scenes themselves where sometimes hard to follow. It seemed like the director was inexperienced when it came to directing action.

I was surprised by the music, which seemed a step up from a lot of other MCU movies.

On a side-note, after the first scenes where we see the lead up to the fight between the heroes in the airport in Civil War, I had to paus this movie and go watch that fight once again. That’s quite amazing considering the fact that before I started watching the MCU movies from start to finish, in sort-of correct story order, that was the scene that I dreaded the most. I was absolutely certain that a scene where our heroes beat the crap out of each other would be just ridiculous in the Batman v Superman kind of way. I was very wrong.

OMG, I actually started writing a song today!

posted this note on and tagged it with Daily photo 2019 snapshots

For the first time in a very long time I started writing a song today. Not an ambient chord progression experiment, not some synth fiddling, but an actual alternative rock song with soaring guitars, pounding drums and lyrics about heartbreak.

To be clear, nothing about it is done yet and long time (really long time) readers of the blog will know that the biggest hurdle for me is always the lyrics. My inability to write lyrics have resulted in a lot of thrown away melody lines and riffs, but this time I’ve got a very clear theme for the lyrics and a persona to write them from. I also have a basic melody, some guitar parts and the outline of an arrangement and instrumentation.

I guess this counts as my ”doing something fun at work” this week, since I worked from home today and the song writing happened when I was about to start working.

First week of The Year of More Fun

posted this note on and tagged it with The year of more fun

First week of 2019 is coming to a close, so I thought it would be a good time for a quick report on my New Year’s Resolutions.

The easy part to report on is the photoblogging. I’ve been doing that every day, except today but I’ll soon get around to posting a picture for today as well. Probably while fulfilling the third bullet on my list, reading at least one evening/night every week.

As for the work stuff, things have not been going as planned but I blamed that on it being i week with only three work days, two of which were booked full with teaching. That means no work from home this week and no three hours for fun stuff.

I did build a ”self-playing ukulele”, but that was used in teaching the very next day so it doesn’t really count as a fun thing without a clear connection to the everyday grind of work.

That’s it for the first week.

2019

posted this note on and tagged it with The year of more fun

Two days ago I took a fairly long walk with Ebbe on the ice of the lake just outside our house. I was rolling him in his stroller so that he could take his daily nap but instead of making as short a trip as possible I decided to keep walking in the beautiful whether and just enjoy myself. During the walk I found out that a few of the very small islands in the lake actually has houses on them, which was news to me. I also started thinking about the year that was almost over, and things to change for 2019. New Year’s resolutions, or Yearly themes if you are C.G.P. Greyish.

More fun at work

One thing that has been quite clear this year, especially during the fall semester is that I’m having less fun at work than I’ve previously had. I think much of it comes down to the fact that this August marked my tenth year as an employee of Dalarna University. I’ve had a lot of fun for those ten years, I’ve learned a ton of stuff and I’ve been able to work on a lot of cool projects. But I’ve also done a lot of the same teaching for most of those years. As I actually started thinking about the fact that it had been ten years, I probably got more sensitive to the daily grind and bore, and the fall are the more dull part of the year at work.

So I feel a strong need to do something about this, to make sure 2019 is a more interesting year at work. The yearly theme, if that’s the way it’s supposed to be framed, is therefore more fun or less bore or something. Please note, not less routine. Routine is important, especially for a one and a half year old and an almost four year old. So it’s not about throwing out routine or make dramatic changes. It’s about making room for fun stuff, even during the boring parts of life.

The first actual thing to do about this is probably also the simplest. It’s something that I’ve done before that I just need to get back into doing and that is making sure I work from home at least ones a week. When I work from home I approach work differently and it’s also very nice having the house to myself for a few hours. Some weeks it won’t be possible scheduling-wise, so it’s not a definitive promise but an important thing to aim for.

Another thing to do to make life, especially at work, more fun is to to make sure I set aside at least three hours every week to do something fun at work. It can be things like making a drum playing robot, making a silly guitar effects video, testing out things for VR/ambisonics, maybe building a midi pedal, fiddling around with our Eurorack synth or any other kind of thing that I have no idea about right now. Things that I technically aren’t payed to do but that tends to benefit my work in one way or another in the long run. I now I can make my schedule work so that I can do this, I just need to actually do it.

Outside of work

I also constantly want to get back into reading, so consider it a resolution that I should read at least once every week, preferable fiction. I am currently reading through Stephen King’s The Dark Tower series and am loving it. Hopefully I might get through a few of those books during the year.

Finally I want to get better at posting pictures from my life, so another resolution is that for the month of January I’m going to post a photo every day. It doesn’t necessarily need to be a photo of something that was a big part of the day, but at least it should get me into the habit of posting more photos.

In short

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My current workflow for dealing with dvds

posted this note on and tagged it with Movies

As previously stated, when it comes to watching movies I don’t like dvds or blurays. However I also don’t like piracy so back in the dvd days I bought a lot of dvds and these days – even though streaming and digital purchases is a thing – I buy a few important movies as blurays.

I recently had a reason to revisit my workflow for dealing with dvds and turning them into mp4-files. Here’s the new workflow that results in a video file that’s playable in QuickTime, on iDevices and a bunch of other devices and that has subtitles that can be turned on or in QuickTIme and iDevices.


  1. For those who, like me, have a native language with å, ä, ö, ø, æ, ï, etc. in it – make sure to install the proper ”tesseract” for Subler 

Captain America: Civil War

posted this note on and tagged it with MCU Movies

🎞 Watched: Captain America: Civil War

Before getting into the MCU, this was probably the movie that I thought would be the very worst one. Super heroes fighting each other over issues that could be solved be talking is just so boring. Turns out, I was wrong about the movie. I really liked this one!

I think we all can agree that this is an Avengers movie, just as much as a Cap movie. And as such it is the Avengers movie, at least in the sense that this is how I would like more of them to be. The world is not going to end if the heroes fail, but instead there are real personal stakes here. I can understand motivations, I can get invested.

As for the fighting, the Avengers movies have the problem that you have a demigod, an almost invincible rage monster, some really powerful metahumans and a spy/assassin and a guy with a bow and arrow. This imbalance of power amongst them gets more or less silly in both Avengers and Age of Ultron (and I assume in Infinity War as well). In this one, it is much better managed. The airstrip scene, which I kind of dreaded, was really exciting. Everybody had an important role and I could understand the abilities of every character and why the could, or couldn’t, match each other.

It was also interesting that I still don’t really know if I’m on team Tony or team Cap. Philosophically speaking I would like to agree with Steve, but I can also totally see myself acting just like Tony does in the final battle, if I were in his shoes.

Right, I almost forgot. Spider-Man! (I’m looking forward to seeing Homecoming.)