For more than 20 years, I’ve been part of the KDE community, one of the largest and most impactful Free and Open Source software community world-wide. Yesterday, KDE turned 30 and this went accompanied with the premiere of the KDE documentary. As former release manager, Plasma core developer and KDE e.V. board member, I’ve also been interviewed. A fairly prominent NPC role went out to Skippie, my cat.
Lately, I have been back into Free Software development, working on two apps that are closely related to hobbies of mine. Watch this space for news! Something nice has been cooking!
On 19th of June, I will open the next edition of Knopje with a 1.5h set of melodic techno. The event starts at 23:00 at GAS19 in Nijmegen. Of course, my friend Roi Koch will also play a set, alongside a number of other fine DJs. Get yourself a ticket.
A project that I had planned for quite some time came to fruition last year, now I finally found time to document the result. My livingroom sideboard looked messy and kind of boring while not blending in anymore with the updated style of my living room. I wanted to turn it into a striking centerpiece of the room. The plan was to install a sound-reactive lighting system. I wanted the light effects to be detailed and not disturbed by ambient sound in the living room, i.e. it sound not react to people’s voices, just the music playing.
My living room sideboard is an off-the-shelf product from IKEA that I bought many years ago. It didn’t have doors installed, but I was delighted that I could still buy matching doors with windows in them. To realize the light effects, I’ve installed frosted plexi glass inside the windows.
Getting technical…
To control the LEDs, I’m using an ESP32-based LED controller with a line-in module and an ADC (analog-digital converter). After some experimenting, I’ve found this board to work well. I’ve connected 6 WS2812B LED strips to 3 pins and installed them with an aluminium profile into the doors. The frosted windows and profiles diffuse the light nicely so you can’t make out individual LEDs really. On the software side, I’m using a sound-reactive port of the WLED project. WLED is Free and Open Source software, of course. Though its user interface can be a little unwieldy, it’s also very powerful and integrates nicely with homeassistant, so it can be controlled automatically.
Inside view
The ESP32, being a rather powerful dual-core microcontroller, can process the incoming audio signal on one core (using fast-fourier transformation) and compute complex LED effects on the other core. Rendering up to 200 frames per second to 2 times 210 LEDs is no problem while power consumption of just the controller stays well under 1W. Pretty impressive! Depending on the LED effects (number of LEDs lit up at a given time and their colors), the whole thing hardly ever reaches 10W of power consumption.
ESP32-based LED controller
Another functional goal of this project was to solve cooling issues of my amplifier once and for all. The amp would run really hot and shut off after playing at higher volume for some time. I installed a bunch of 12cm fans which suck air through the amplifier and blow it out on the backside. Both amp and and fans are connected to smartplugs. I turned to my homeassistant and set up an automation which turns the fans on whenever the amp’s power consumption reaches a certain level. This works really nicely, since the fans never spin at lower volumes (when you could hear them through the music) and keep everything cool and running stable at higher volume when it’s necessary — without human interaction.
Cooling system
Walnut finish
The outer shell of the sideboard is made of walnut wooden panels with an oil and varnish finish, thanks to my friend Joris. The oil gives it a darker look and accentuates the grain, matching the speaker system. The matte varnish finish (Skylt, highly recommended for its durability and natural look) allows me to sleep well even if people put their drinks on it.
Done and dusted
I love it when a plan comes together!
I’m really happy with the result. While I had thought it out for a long time already, it’s always a lot more impressive when you see the final result in action. The WLED firmware allows me to create interesting light effects. I can run the 3 doors as one, but also easily split them up into segments so each door panel renders its own effect. WLED has ca. 200 different LED effects, many of them react to sound. Each effect can be combined with one of 50 color palettes, some of the palettes are sound-reactive in their own right leading to a very dynamic display. One cool feature is that the processed sound data can be broadcast across the network (over UDP) and received by other WLED controllers, so I can have multiple LED displays in the house, each rendering their own effect to the music, creating a more immersive experience.
Recently, I’ve worked on making certain “less obvious” system settings more accessible for Plasma Mobile users. The modules I’ve worked on fall just outside the typical mobile phone use-case, but can be important to users of other types of devices. Specifically, users that plug in or connect a keyboard once in a while and need to change its layout or language, or devices that are connected using an ethernet cable, as often is the case with embedded industrial devices.
Mobile keyboard settings
Wired network settings
These two settings module offer a subset of their “desktop companions'” settings and cater to simpler use-cases while sporting a leaner and more focused user interface. Most of the business logic and the more complex UI components are also shared with the desktop versions.
Reviewers needed!
The merge requests for both are currently under review and I’d appreciate if people could help ironing out issues so we can go ahead and merge the code:
After I took a longer break from KDE development, I’ve been back in action for a few months now. It’s really nice to be back among friends, hacking on what I like most: Plasma. My focus has been on Plasma Mobile with some work naturally bleeding over into other areas.
Plasma on more Devices
I’d like to share some bits and pieces that I’ve worked on in the past months. Most of my efforts have revolved around making Plasma Mobile suitable for a wider range of devices and use-cases. The purpose of this work is that I want to make Plasma Mobile a more viable base for all kinds of products, not just mobile phones. We have a really mature software stack and great tools and applications which make it relatively easy for companies to create amazing products without having to hire large teams and many years to get the product ready for their market. This is I think a very interesting and worthwhile niche for Plasma to get into and I’m sure that Valve is not the only company that understands this.
Convergence Improvements
Convergence, or rather being able to support and switch between formfactors and usage patterns has always been a pet-peeve of mine and still is. One area was improving using the available screen real estate use landscape displays (Plasma Mobile has quite naturally been rather “portrait-focused”, though a few smaller patches go a long way.)
Configurable number of columns in the Quicksettings drawer
I also improve usability with different pixel densities in the mobile shell by making the size of the top panel configurable. Also, when plugging in a second monitor, Plasma Mobile now switches from “all apps are maximized” to normal window management. (I’m currently working on KWin supporting more fine-grained window management. Currently, we just maximize all windows which has problems especially with modal dialogs.)
One changeset I worked on earlier this year makes it possible to ship multiple user interfaces for settings modules (“kcms”). An example is the “remote desktop” kcm which now shows a mobile-focused UI in Plasma Mobile. What happens here is that we load a main_phone.qml file in Plasma Mobile (where “phone” is picked from a list of form factors set in the environment of the session, so basically the “main” QML file gets picked based on the device. This mechanism allows us to share components quite easily, reducing the delta between different device UIs.
Mobile and Desktop RDP settings
This actually builds on top of work that I’ve done ten years ago which added support for form factors to our plugin metadata system. I’ve also made the “Display & Monitor” kcm usable on mobile, this is a pretty important thing to have working when you want to be able to plug in an external monitor into your device. I have a mobile version of the keyboard KCM in the pipeline, too, but this will need a bit more work before it’s ready for prime-time.
More Features
There’s a new page in the mobile Wi-fi settings module, showing connection details and tranfer speeds. The code for this was amazingly simple since I could lift most of the functionality from the desktop panel widget. A shared code-base across devices really speeds up development.
Connection details for the mobile wifi settings
Adding useful features here and there, such as having the list of available bluetooth devices now filtered by default and only showing devices which actually make sense to pair (with an option to “Show all devices” in good Plasma manner). This feature isn’t mobile-specific, so desktop and laptop users will benefit.
Welcome to Okular Mobile
Not all my work goes into infrastructural and “shell” bits. The mobile okular version has now kind of caught up with the desktop version since it got a nice welcome screen when opened. This allows the user to easily open a document either from the “Documents” directory on disk (this is actually configurable) or one of the recent files viewed.
Okular Mobile Welcome Screen
Going to Akademy ’25
After having missed our yearly world conference for a number of years, this year I will be at Akademy again. I’m really looking forward to seeing everybody in person again!
Lots of KDE hacking these days, and that comes with compiling large amounts of code. Right now, I am installing, well building from source Plasma Mobile on an “old” laptop so I can test some patches natively on a touchscreen device. The machine has just two cores (hyperthreaded), so builds take rather long, especially if you build Qt and all that 80+ packages that are needed for a fully working Plasma system. One of the tools that do an incredible job while being super flexible to use is icecream. Icecream (or “icecc“) allows you to distribute your build over multiple machines, it basically ships compile-jobs with all that’s needed to other machines on a local network, meaning you can parallelize your builds.
Icecream has this nice visualization tool, called icecream-monitor which you can stare at while your builds are running (in case you don’t have anyone handy for a sword-fight). In the screenshot you can see manta, the underpowered laptop doing a 32 parallel job build over the network. miro is my heavy workstation, 8 cores and 128GB of RAM, it duely gets the bulk of the work assigned, frame is my (Framework) laptop, which is also quite beefy, gets something to do too, but not taxed as heavily as that build monster in my basement office. Icecream can be used with most environments that have you run your compiler locally. Different distros are no problem! Just a matching CPU architecture is needed. Icecream does its job by providing its own g++ and gcc binaries, which will relay the build jobs transparently to either your local machine or across the network. So you basically install it, adjust your PATH variable to make sure icecc’s g++ is found before your system’s compiler and start your build. Other machines you want to join in for the fun just need to run icecc-scheduler and they will be automatically discovered as build slaves on your network. If you want to further speed up builds, it works with ccache as well.
Please note that you only want to do this in a trusted environment, we’re shipping executables around the network without authorization!
Some of you may be wondering what I have been up to lately since I took a break from my work in the KDE community. Well, it was time for a change, a change towards family, friends and a more local life. The result is a more balanced, a more grown up me. These changes in my life lead to me having a small family and a group of new friends, both of which I spend a lot of time with. They brought more light into my life, one could say.
That is not all I want to talk about, however. I the past 1.5 years I worked on a new project of mine that combines my love for software with the physical world. I created a product and brought it to the market last month. Now, we’re ready for the international launch of Organic Lighting. The product is a design smart lamp for the living room. It combines unique and dynamic visual effects with natural, sustainable materials. Meet our Aurora lamp:
It’s a connected device that can be eighter controlled using its physical knob on the front, or via its web ui (or REST interface). Effects can be changed, tweaked and its firmware can be updated (nobody should want an IoT device that can’t get security of feature updates). The concept here, technically is to do “light in software”. The lamp is run by a microcontroller embedded in its foot. Its roughly 600 leds produce ca. 4000 Lumen and render effects at more than 200 frames per seconds. The lamp is built with easy repairs in mind, and it’s designed for a long-lasting experience, it respects your privacy, and it creates a unique atmosphere in your living space.
With our products, we’re offering an alternative to planned deprecation, throw-away materials and hidden costs of cheap electronics that make you the product by consuming your data for breakfast.
In the future, we will build on these concepts and technology and offer more devices and components that match our principles and that enhance one-another. Stay tuned!
This morning, while browsing the web, I wanted to listen to a Podcast from my laptop, and thought “Hey, can I stream this to our stereo?”. As it turns out, that’s rather easy to achieve, so I thought I’d share it here. The media devices in our home are connected using Chromecasts, which are small dongles that allow playing media on them, meaning you can play for example a video from your phone on the projector in the living room: very convenient.
I didn’t know if that was easily achievable with audio from my Plasma/Linux laptop and a quick search turned up “pulseaudio-dlna” which adds Chromecast devices on the local networks as output devices.
On my KDE Neon laptop, it’s as easy as installing pulseaudio-dlna from the standard repositories and then starting “pulseaudio-dlna” from the commandline. Then, I can pick an output device from the panel popup and the audio stream changed to my stereo.
For my hacking, I love to use the KDevelop IDE. Once in a while, I find myself working on a project that has different indentation styles depending on the filetype — in this case, C++ files, Makefiles, etc. use tabs, JavaScript and HTML files use 2 spaces. I haven’t found this to be straight-forward from KDevelop’s configuration dialog (though I just learnt that it does seem to be possible). I did find myself having to fix indentation before committing (annoying!) and even having to fix up the indentation of code committed by myself (embarrassing!). As that’s both stupid and repetitive work, it’s something I wanted to avoid. Here’s how it’s done using EditorConfig files:
put a file called .editorconfig in the project’s root directory
specify a default style and then a specialization for certain filetypes
restart KDevelop
Here’s what my .editorconfig file looks like:
# EditorConfig is awesome: https://EditorConfig.org
# for the top-most EditorConfig file, set...
# root = true
# In general, tabs shown 2 spaces wide
[*]
indent_style = tab
indent_size = 2
# Matches multiple files with brace expansion notation
[*.{js,html}]
indent_style = space
indent_size = 2
This does the job nicely and has the following advantages:
It doesn’t affect my other projects, so I don’t have to run around in the configuration to switch when task-switching. (Editorconfigs cascade, so will be looked up up in the filesystem tree for fallback styles.
It works across different editors supporting the editorconfig standards, so not just KWrite, Kate, KDevelop, but also for entirely different products.
It allows me to spend less time on formalities and more time on actual coding (or diving).
Plasma’s new screen layout selection dialogThis week, Dan Vratil and me have merged a new feature in KScreen, Plasma’s screen configuration tool. Up until now, when plugging in a new display (a monitor, beamer or TV, for example), Plasma would automatically extend the desktop area to include this screen. In many cases, this is expected behavior, but it’s not necessarily clear to the user what just happened. Perhaps the user would rather want the new screen on the other side of the current, clone the existing screen, switch over to it or perhaps not use it at all at this point.
The new behavior is to now pop up a selection on-screen display (OSD) on the primary screen or laptop panel allowing the user to pick the new configuration and thereby make it clear what’s happening. When the same display hardware is plugged in again at a later point, this configuration is remembered and applied again (no OSD is shown in that case).
Another change-set which we’re about to merge is to pop up the same selection dialog when the user presses the display button which can be found on many laptops. This has been nagging me for quite a while since the display button switched screen configuration but provided very little in the way of visual feedback to the user what’s happening, so it wasn’t very user-friendly. This new feature will be part of Plasma 5.13 to be released in June 2018.
