Home Automation – sebas' blog

Sound-reactive Sideboard

March 4, 2026March 4, 2026 1 Comment

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.

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.

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.

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.

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.

Bringing light to life

November 19, 2020February 23, 2022

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!

Streaming audio from Plasma to a Chromecast

January 20, 2020 3 Comments

Chromecast devices in the sound settings

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.

$ sudo apt install pulseaudio-dlna
[...]
$ sudo pulseaudio-dlna
[...]
Added the device "Stereo (Chromecast)".
[...]

Desk lamp

July 20, 2019July 20, 2019

Some time ago, I wanted to make my own desk lamp. It should provide soft, bright task lighting above my desk, no sharp shadows that could cover part of my work area, but also some atmospheric lighting around the desk in my basement office. The lamp should have a natural look around it, but since I made it myself, I also didn’t mind exposing some of its internals.

I had oak floor boards that I got from a friend (thanks, Wendy!) lying around. which I used as base material for the lamp. I combined these with some RGBW led strips that I had lying around, and a wireless controller that would allow me to connect the lamp to my Philips Hue lighting system, that I use throughout the house to control the lights. I sanded the wood until it was completely smooth, and then gave it an oild finish to make it durable and give it a more pronounced texture.

The center board is covered in 0.5mm aluminium sheets to dissipate heat from the LED strips (again, making them last longer) and provide some extra diffusion of the light. This material is easy to work with, and also very suitable to stick the led strips to. For the light itself, I used SMD5050 LED strips that can produce warm and cold white light, as well as RGB colors. I put 3 rows of strips next to each other to provide enough light. The strips wrap around at the top, so light is not just shining down on my desk, but also reflecting from walls and ceiling around it. The front and back are another piece of wood to avoid looking directly into the LEDs, which would be distractive, annoying when working and also quite ugly. I attached a front and back board as well to the lamp, making it into an H shape.

Light reflects nicely from surrounding surfaces

The controller (a Gledopto Z-Wave controller, that is compatible with Philips Hue) is attached to the center board as well, so I just needed to run 2 12V wires to the lamp. I was being a bit creative here, and thought “why not use the power cables also to have the lamp hanging from the ceiling?”. I used coated steel wire, which I stripped here and there to have power run through steel hooks screwed into the ceiling to supply the lamp with power while also being able to adjust its height. This ended up creating a rather clean look for the whole lamp and really brought the whole thing together.

IKEA Trådfri first impressions

November 23, 2017November 23, 2017 2 Comments

Since I’ve been playing with various home automation technologies for some time already, I thought I’d also start writing about it. Be prepared for some blogs about smart lighting, smart home and related technologies.

Most recently, I’ve gotten myself a few items from IKEA new product range of smartlight. It’s called trådfri (Swedish for wireless). These lights can be remote-controlled using a smartphone app or other kinds of switches. These products are still fairly young, so I thought I’d give them a try. Overall. the system seems well thought-through and feels fairly high-end. I didn’t notice any major annoyances.

First Impressions

My first impressions are actually pretty good. Initially, I bought a hub which is used to control the lights centrally. This hub is required to be able to use the smartphone app or update the firmware of any component (more on that later!). If you just want to use one of the switches or dimmers that come separately, you won’t need the hub.
Setting everything up is straight-forward, the documentation is fine and no special skills are needed to install these smartlights. Unpacking unfortunately means the usual fight with blister packaging (will it ever stop?), but after that, a few handy surprises awaited me. What I liked:

The light is nice and warm. The GU10 bulbs i got give 400 lumens and are dimmable. For my taste, they could be a bit darker at the lower end of the scale, but overall, the light feels comfy warm and not too cold, but not too yellow either. The GU10 bulbs I got are spec’ed at 2700 Kelvin. No visible flickering either.
Trådfri components are relatively inexpensive. A hub, dimmer and 4 warm-white GU10 bulbs set me back about 75€. It is way cheaper than comparable smartlights, for example Philips Hue. As needs are fairly individual exact prices are best looked up on IKEA’s website by yourself.
The hub has a handy cable storage function, you can roll up excessive cable inside the hub — a godsend if you want to have the slightest chance of preventing a spaghetti situation.
The hub is USB-powered, 1A power supply suffices, so you may be able to plug it into the USB port of some other device, or share a power supply.
The dimmer can be removed from the cradle. The cradle can be stuck on any flat surface, it doesn’t need additional cabling, and you can easily take out the dimmer and carry it around.
The wireless technology used is ZigBee, which is a standard thing and also used by other smarthome technologies, most notably, Philips Hue. I already own (and love) some Philips Hue lights, so in theory I should be able to pair up the Trådfri lights with my already existing Hue lights. (This is a big thing for me, I don’t want to have different lighting networks around in my house, but rather concert the whole lighting centrally.)

Pairing IKEA Trådfri with Philips Hue

Let’s call this “work in progress”, meaning, I haven’t yet been able to pair a Trådfri bulb with my Hue system. I’ll dig some more into it, and I’m pretty sure I’ll make it work at some point. If you’re interested in combining Hue and Trådfri bulbs, I’ll suffice with a couple of pointers:

If you want to try this yourself, make sure you get the most recent lights from the store (the clerk was helpful to me and knowledgable, good advice there!). You’ll also likely need a hub at least for updating the firmware. If you’re just planning to use the bulbs together with a Hue system, you won’t need the hub later on, so that may seem like 30€ down the drain. Bit of a bummer, but depending on how many lights you’ll be buying, given the difference in price between IKEA and Philips, it may well be worth it.

\edit: After a few more tries, the bulb is now paired to the Philips Hue system. More testing will ensue, and I’ll either update this post, or write a new one.