Henrik Carlsson's Blog

Thanks Aaron. So far I’m happy with it, though I think I realised what I compromised on by buying such a comparatively cheap polyphonic synth (as compared to say a Prophet 12 or something). I would like a whole bunch more modulation, both sources and destinations.

My other synth is a DSi MoPho, which is monophonic and its modulation matrix is annoying to program but gloriously flexibel.

So far I don’t have any Volcas but several of those where on the table for me when I decided on which synth to buy. The Volca Modular har more of a Buchla approach to things, rather than a Moog style approach to things, right?

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@odd That sounds like a reasonable approach to things.

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@petebrown and @macgenie I see, thanks! I’ve never used any kind of pressure cooker so this was new to me. Reading the list of the things the InstantPot can do makes me want one.

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@macgenie Same here, but also with the sense of annoyance over all these people – not just Billy – who want to be ”the next Steve Jobs” or who want to make their company ”the Über of [insert whatever]”. So annoyance over start-up culture in general, I guess.

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@furstenberg You are kind of selling me on the director’s comments. So far I don’t think I’ve ever watched a movie with the director’s commentary track, but maybe this will be the first. Thanks!

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@odd You are right, off course. The problem is that I find the ignore part hard to do.

And that’s probably why I feel especially negative toward the idiots on ”the left”, rather than on ”the right”. The stupidities of ”the right” is fairly simple to ignore. Just don’t read their fringe publications. Ignoring stupidities from ”the left” on the other hand would require me to ignore so much mainstream press.

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I am probably the odd man out here, but when I talk about my problems with the ”culture war” destroying my will to rewatch The Last Jedi, it is mainly not because of Evil Right-Wing-Alt-Right-Nazi-Incel-Hobgoblins, it’s because of their opposite yet still strangely similar counterparts telling me that if I don’t love this movie, it’s probably because I’m a misogynistic racist who hate people who aren’t skinny.

It’s gotta be possible to find a movie okay but not great.

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@furstenberg The Last Jedi will probably grow on me to once I rewatch it. The problem for me is that it got caught up in the stuped ”culture war” that we seem to be fighting on the internet every single day.

Was it that the commentary helped in expressing his intentions with the movie, or where they just fun/interesting comments?

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2020, the year when I start buying plastic discs again

Yes, DVDs and blu-ray still suck but having to say ”no, we can’t watch that movie on this tv because it doesn’t have an AppleTV connected, so let’s go to the other room and watch it there” is worse and there are solutions.

2020 is the year when I start buying plastic discs again.

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@adamprocter Probably, but it still worth it to have those days where you feel like you’re hitting it out of the park.

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@adamprocter Good work! Those kind of days are so rare and so great, as opposed to those where you feel like you have at least ten things more on your todo list that should have been done that day.

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As I’m moving back from Christmas into normal work weeks, I need to get back into micro.blog as well.

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@ronguest Thanks Ron, that’s very kind of you.

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@odd Håller med. Och sen är det väl där den stora ideologiska trätofrågan är, alltså hur vi bekämpar fattigdom.

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@furstenberg Seems more or less like my impression. I definitely need to see Rise of Skywalker again before forming a proper opinion, but I should probably also see The Last Jedi again. I’ve only seen both movies once.

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I’m filing these away here for now. They will likely be the speakers of the πi Fi.

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@ Greg McVerry Here you go. Watch and listen at your own risk. https://www.youtube.com/watch?v=BQkSIcI62kM

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Yes, this tutorial more or less works for me now. The more or less part is that the values I read is quite unstable. I wonder if that is because I’m not using a proper power supply for the Pi. I need to investigate further another day.

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Slight update on the πiFi: I’ve got a power button an power status LED working on my GPIO test Pi now. I’ll need to go to bed soon but I think I’ll give the level potentiometer a go first.

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Tonight I managed to sit down and experiment with the GPIOs of the Raspberry Pi. I think I’m getting the hang of how they work now but I gotta say, this is the first thing I’m doing with the Pi where I feel like it lacks a lot compared to the Arduino.

Anyway, I got some basic buttons working. Tomorrow, or whenever I sit down with it again, I’ll give the level potentiometer a go again.

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The plan right now is to 3D print a sort of beta enclosure for the πFi Music Player. Maybe the final product will have an enclosure built out of wood and/or metal, so maybe this is just a temporary solution but it at least gives me something less brittle than a couple of Lego bricks to hold it together while I experiment with it.

We have a 3D printer at work that I can use but I’ve never 3D printed anything, nor have I 3D modelled anything so I have quite some learning to do.

A friend recommended that I’d use Fusion360 because it’s a very capable program that’s also free for academics. I downloaded and opened it, and quickly closed it again because it felt like something completely alien to me.

The same friend then recommended this tutorial on Fusion360 to get started, and while I haven’t applied what I saw in it yet at least it feels like I now know somewhat where to start.

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Tonight I tried to get the volume control working for the πFi. I followed a guide on how to make it, but I failed miserably. I’m still not sure what it is that isn’t working, and that’s the problem.

I have zero prior experience with using the GPIO’s of the Raspberry Pi, and using them while using the HiFiBerry makes it even more complicated so I need to rethink this.

I’m going to place an order for a proper break-out board for the GPIO and some additional components to be able to breadboard and try things out, and I’ll need to put the physical controls part of the project on hold until that has been delivered.

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The πFi Music Player

Every project needs a name and I need to stop referring to the music player I’m building as "The Kid’s Music Player". So, the project name is from now on The πiFi Music Player or πFi for short.

The basic idea is to replicate the very kid friendly1 way of listening to music that a cassette player or CD player was back when I was a kid. Today we can all access pretty much every piece of music ever recorded but to do so you pretty much have to have a smart device of some kind and be able to read and write to find what you are looking for.2

To do this I’m building a device that scans pieces of cardboard with QR codes on them and then uses the information on the QR code to playback the correct track, album or artist from Spotify. (Local play might also be a feature.) The side of the "music card" that doesn’t have a QR code will have album art or similar to make it easy to identify to both adults and kids.

I currently have a soon to be alpha in my hands (or on my bookshelf). I’m using a Raspberry Pi with Mopidy for the playback, a Raspberry Pi Camera module and zbarcam to scan the QR codes, a Python script to actually do something with the information in the QR and then a HiFiBerry Amp2 to DA convert and amplify the audio for a pair of passive speakers.

As you can see in the video the physical/crafty side of the project has a lot of work that needs to be done. I’m currently using some LEGO to keep things in place, but I need a proper enclosure. I’m not 100% sure whether I’ll make something out of wood, metal or whether I’ll 3D print something unapologetically plastic. 3D printing seems like a good idea because it simplifies making more than one device, which I’m planning to do. However, I’m never 3D printed anything. Nor have I built a 3D model of anything, so I’ll have some homework.

Even more important before it can be considered even an alpha is a volume control. Right now, the only way to control the volume is to SSH into the Pi and use mpc volume XX where XX is the percentage of volume I want. Because the amplifier is 2x 30 Watts, it’s quite loud in a normal home setting. As I’m listening while typing now I have it set for 7% volume.

The WAF of SSHing into something to change it’s volume from ear-piercingly loud to tolerable is very low.3

I also think it need some kinds of physical controls, at least for play/pause, stop and next track. Right now those functions are also accessed via QR codes.

Before moving it into beta I also need to build speakers. I have borrowed the ones I’m using now from a friend. I might also build a proper power supply for it, instead of using the wall wart that I use now.

Many things are still uncertain and there are so much I need to learn how to do, but I am really happy to have started this project, and that I actually got back to it after having left it dormant for three mounts.

If you want to follow along everything will be published here on the blog. I’ll try to remember to tag all the posts with πiFi Music Player.


  1. Or "non techy person" friendly.  ↩

  2. Yes, I am aware of "smart speakers", ladies in cans and "AHOY TELEPHONE". Here’s some reasons why that’s not a solution here.  ↩

  3. Yes, "Wife Acceptance Factor" is probably a very problematic term these days. I think we should try to change it to "PAF – Partner(s) Acceptance Factor". The idea itself, that something that appeals to a nerdy person doesn’t necessarily appeal to the other person(s) living with the nerd, still has merits and is worth considering when building and/or purchasing something like this. Regardless of the gender and/or pronoun of the nerd and the other person(s) involved.  ↩

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The Raspberry Pi Camera module does seem to work for the music player, but it did cause me some headaches initially.

The first problem I encountered seemed to stem from a sloppy physical installation of the camera. Once I removed it from the Pi and inserted it back in, it worked.

The second problem seems to be that by default the camera cropped the sensor data, so the QR code couldn’t be read as close to the camera as I wanted. Adding --prescale=640x480 as and argument to zbarcam appears to have solved the problem.

Tomorrow I’ll try using the HiFi Berry Amp2 as well.

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It appears that I was quite good at documenting my work on the music player, so I’m up and running again now.

Previously I’ve used an old USB webcam (actually a PlayStation eyeToy Camera) as the scanner and it has worked fine. However I wanted something different in the long run, so yesterday I bought a camera module for the Raspberry Pi.

The main thing I’m doing tonight, apart from getting back to where I were, is to test whether this particular camera works or not. So far it has not been plug and play but maybe it was foolish of me to expect that. As I’m writing this I’m doing a apt-get update and apt-get upgrade and then I’ll have to do some configuration in raspi-config.

Also, I’m starting to get reaaaaaaally tired so I’ll probably call it a night pretty soon. I blame daylight savings time.

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Linn and I finished watching Stranger Things Seasons 2 and 3 yesterday and since we don’t have any other show queued up, now seems like a good time to resume my work on a music player for the kids.

Right now I’m mostly trying to figure out how far I got the last time I worked on it.

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@tiffany

I’m just raising my hand and saying that I’m very interested in whatever you talk about in regards to home automation. That stuff is always interesting.

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@sirshannon Well, I don’t own one. Yet(?)

But the series 5 is the model so far that’s most likely to get me to buy one. The always on display takes care of the single most annoying thing about the previous ones, and one of the things that Pebble really got right, and the fact that I don’t have to pay for a band that I won’t use is another great feature.

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@Gabz Can you be a bit more specific?

I’m not going to try to convince you that you are wrong, I’m just curious because Hello Internet is my favourite podcast (along with Grey’s other podcast Cortex) .

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Two weeks ago I was away on a work trip and I decided to try to capture footage to potentially make a vlog out of. Here’s some lessons I learned.

So no, there won’t be a finished vlog this time but is was fun to try.

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@ronguest Then that’s not exactly the right solution now, but your post gave me an idea. I seem to recall FreeNAS being a software based NAS, and there are probably other similar products as well. Maybe one of those has a photo sharing feature.

Original post.

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@ronguest That sounds interesting, but am I right in assuming it’s for the Synology NAS only? I currently don’t use a NAS (I have an old Drobo gathering dust on a shelf) and I was hoping to solve this with either my Linode or an always on MacMini.

Original post.

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I need your help finding a self-hosted alternative to iCloud photo sharing

I’m looking for a self-hosted alternative to iCloud photo sharing for private photo sharing with the family, and I need your help finding it.

Here’s what’s great about iCloud sharing:

The main problem is that it is exclusive to the Apple ecosystem. That excludes part of the family. If I’m going to change things up it would also be nice if the new solution was hosted on a server controlled by me.

So, a self-hosted alternative to iCloud photo sharing, with apps for viewing on both iOS and Android. Any recommendations are much appreciated.

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@Cassinato I recommend Overcast and Castro. Overcast is my favourite, but for I while I did use Castro and really liked it because of its queue feature.

Since you don’t listen to that many shows I’d say Overcast is the best way to go.

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@smokey As I read the third paragraph of your post I literally thought ”my head hurts”. Then I read your forth paragraph. :D

Anyway, thanks for adding it to the wiki. Follow up question though, what wiki? Where do I find it?

I wonder how many webmentions I receive if I also reply to my original post here?

Regarding your second post,

1) Used the share sheet and selected ”Dela som fil”, which I assume is called ”Share as file” (or possibly ”Save as file”) in English. That brings up a second share sheet in which I could save it to the files app. From there I uploaded it to GitHub.

2) I’m not sure and haven’t tried it, but I assume you could use the download link on GitHub, save it so files and then open it there and chose to import it.

Be aware, the Shortcut is very much a hack solution right now. It totally butchers the result if the post you are trying to reply to originates from a non-hosted micro.blog account.

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@Miraz That makes it even better. Thanks!

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@manton I just wrote up my process in getting the external replies to work. Not sure if it’s actually a bug report, but feel free to read the steps I took and see if I missed or mis-interpreted anything.

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Replying to micro.blog posts, directly from my blog

Lately I’ve started to use micro.blog more actively again. As part of that I’ve also started to reply more to posts and have stimulating conversations. That made me realise that those conversations might be of interest to have on my own site, so I should really try to set up my system so that I can reply to micro.blog posts directly from my blog. Yesterday some free time opened up during the evening so I gave it a go and it more or less works.

So first off, here’s my setup. I self host a WordPress blog. It uses a theme that I’ve made myself and quite a few plugins that I didn’t make. The important plugins in this context should be IndieWeb, Post Kinds, Semantic-Linkbacks and probably most important Webmentions.

There’s a help page on micro.blog about called ”Replies and @-mentions” that tells us that:

For an external blog post that is a reply to a specific Micro.blog post, the external blog can send a Webmention to Micro.blog. As long as the sending blog is associated with a Micro.blog user, that post will be copied to Micro.blog as a reply and threaded into the conversation. Micro.blog’s Webmention endpoint is: https://micro.blog/webmention

So that’s what I tried to set up. I created an iOS Shortcut for my iPhone and iPad that I can trigger from the ”Share” menu in the micro.blog app that creates the hyperlink and fills in the @username-part. It then asks me for my reply as input text and finally sends it off to my blog.

On the Mac I don’t have quite such a nice automation workflow yet. Instead I just have a TextExpander snippet to fill in the hyperlink a bit faster.1

I also mark up the hyperlink with class="u-in-reply-to", though from the help text I suspect that’s not fully necessary.

Getting things working

The thing I knew I had to tweak was the part about how ”as long as the sending blog is associated with a Micro.blog user”. I’ve had multiple people reporting to me before that my webmentions shows up as sent by anonymous rather than as me, so I figured I had to sort that out first. To do that I used the Indiewebify.me service and checked how well my blog did the ”Become a citizen of the IndieWeb” and ”Publishing on the IndieWeb Level 2 – 1. Mark up your content (Profile, Notes, Articles, etc…) with microformats2” parts.

They showed that I had some tweaking to do, mostly because I had mistakenly only marked up part of my h-card as such so a lot of things where missing.

When that seemed to work I made a test reply to one of my own posts on my blog and the webmention had my name attached to it, so that seemed like progress.

I then sent out a post asking for people willing to receive some test replies and John (@johnjohnston) and Ron (@ronguest) where kind enough reply. The first proper test almost worked. It did show up a a reply but it identified as sent by blog.henrikcarlsson.se instead of by @MrHenko, so some part of micro.blog identifying me as me didn’t work.

So I dug around some more and realised that I had inputed http://henrikcarlsson.se as my web site in micro.blog’s account settings. While that is technically true, as my blog posts comes from the subdomain http://blog.henrikcarlsson.se, so I tried changing to the latter in micro.blog and that worked. My replies on my blog arrives properly threaded in micro.blog and properly attributed to @MrHenko.

One glaring problem remained though. Every reply from me got double-posted. I assume that is because I technically do send two things to micro.blog. A webmention from the blog post and then the post itself because it shows up in my RSS feed that is used to feed micro.blog.

My solution was to post my replies in a special ”interactions” category that I use the Ultimate Category Excluder plugin to exclude from my main RSS feed. And with that in place things more or less worked as intended.

Some things that still need tweaking

Every time I make a new reply in a thread in a micro.blog conversation, that’s a new post on my blog.2 That is in itself not a big problem but the curious part is that every reply that somebody else makes in the thread results a webmention/comment to multiple of the posts that I’ve made that has been threaded in that particular conversation. So I get duplicate comments, but on differens posts on my blog.

Right now I deal with it by only approving the comment to the earliest post I’ve made in the thread but that doesn’t really quite work since my subsequent comments doesn’t show up as comments on my own first post on my blog. So I’ll need to look more into this.


  1. Litteral sidenote: The prospect of Shortcuts on the Mac is what makes me the most interested in updating macOS this fall. 
  2. I’ve tried to get it to send comment replies as webmentions but that doesn’t seem to work. 

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🔈 Now playing: R.E.M. – Document

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@manton Which of the posts are those? I can’t seem to find them.

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