Diskokugel Electronics

April 21st, 2011

Christian provided me with some sample circuit boards which I assembled the last days.  Christian already had soldered the smd parts in place . Considering my latest clumsy attempts with the icosahedron, this was a wise thing to do. It was still a lot of work to just get the ICs and transistors in place. Once done, I discovered a major flaw in our board design, since the connectors aren’t yet ready to cascade the things. Back to the drafting board…

However, now it’s done and I can run a test with 40 speakers!

Five boards to run tests. The smaller one is the first Christian assembled, the others are ready to be attached to the icosahedron.

Re: Diskokugel (icosahedron 2) [Updated]

April 8th, 2011

I can’t believe how much time this took. I tried to find someone to help me weld theicosahedron but whatever I tried, something always went wrong. So, finally, I did it by myself. The result is pretty ugly (compared with how it started) and I guess I’ll have to invest some money to have someone professional do this once it proves to be a working concept. Thank god I don’t rely on my soldering talent to survive…

Not pretty. But robust.


I took a part of the frame and used some acrylic compound to attach some bodies to it. I am not quite satisfied with the looks of the compound. I’ll try black hot glue the next days. Another alternative could be silicone.

Then I started to solder shims to the points where the frame will be attached to the icosahedron. Lot of work. Lot of progress.

full view from above. You can see the icosahedron inside.
From the inside you can see the chrome bodies
another full view

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A little LED-Lamp

February 28th, 2011

I built a lamp for my girlfriend. It’s quite simple: I took a rotating part of a lamp I broke some time ago (some stupid aquarium simulation), a spare 3 color Cree LED and chicken wire. A little cheesy but quite nice. If you lie on the ground an watch it for some time, the spiral seems to stop and the room rotates instead.


The LED lamp

the knob lets you choose the color or the speed the color changes

color LED lamp

the turning mechanism

inside: a 12V power supply and a constant current supply for the led, an atmega 328 (arduino)

Of course, the Atmega32-8 is completely oversized for such a project, but it was at hand and programmable via the Arduino. I’m sure the extra constant current supply is also obsolete, but I didn’t get to try otherwise. Comments how to optimize the setup are always appreciated.

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Diskokugel Progress

January 23rd, 2011

My work for the Computerspielemuseum (video game museum) is done, so I started right away to work on my Diskokugel again. Theres a few updates form the last time I posted on this:

I decided to stay with the wireframe as it is, not filling the blanks in between. I think, looking into the thing is just as mindblowing as looking at it, especially because I came up with a solution for the resonating body of the speakers: chrome christmas baubles! Since it was the time of the year I found some made of plastic in just the right size to fit the speakers. Another problem solved.

Kitsch is the solution...

Secondly I sat down looking for a solution to keep the whole ball stable and to attach the electronics to. The surface of the ball has 12 “blank” spots (the centers of the pentagons of the soccer ball pattern). Here, something could be attached to connect to a support inside. So I was looking for a body with 12 corners, an icosahedron. It took me only about three ours to solder this model:

There she is

Quite beautiful, isn’t it? The plan is, to have either a shim or a nut on each corner and to connect to the “surface” via thread bars. The circuit boards will be attached to the edges, making it a kind of star floating within the ball with lots of wires leading to the surface (I will probably wind them around the bars).

I replaced the corners with nuts. Two thread bars sticking in.

Problem right now is, to construct this support in a manner that actually will carry the load. the thing on the picture is soldered with regular solder and won’t last. I’d have to at least braze or weld the stuff. A first attempt to braze it at home failed miserably, so I’ll have to look for help somewhere.

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PD Video Player with Sound

November 13th, 2010

I had the idea to build a kind of solid state video player using Linux and Puredata with an Arduino. The educated reader might ask “Why PD?” and, of course, is right. The simple answer is: Because I can and its easy.

I take the latter back. When I came up with this I had totally ignored, that Puredata/Gems Pix_Film object doesn’t play sound. This means, video and sound have to be played in separate players and then be synced. Some research in PDs list gave me an example I started working with and I was partially successful. Video and sound sync well with a [vline~] but with high resolutions the sound glitches. This can be reduced by trying different video codecs (motionjpg is supposed to work pretty well) but still I wasn’t able to play 1280×1024 videos without the sound dropping sometimes. I didn’t have this problem using the [pix_buffer] object, but this way the video is loaded into the RAM uncompressed, which takes up tons of space and limits the possible length of videos loaded/used. This was on my MacBook with 2x2GHz and an onboard Intel 9400m graphics card. I will try it on Linux in the next days, lets see, if it works better.

However, I expect no wonders and theres no sense in building a solid state video player that needs hardware this expensive (and energy intensive). I want to use one of these fit-pcs, loving their small design and power consumption. For them to work with videos of that resolution I need to use their hardware acceleration, which might prove difficult on Linux (I heard nothing good about the support of intels gma500) and even worse when relying on PD/Gem, which uses OpenGL to render video. So the plan now is to use a common video player like VLC or mplayer and remote control it via network/localhost. That should take care of the hardware acceleration and still make use of the serial interface and interaction possibilities of PD. Stay tuned…

Pure Data Video Player with Audio Sync

This patch syncs video and audio



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Solar Collect Call by Thomas Saraceno

November 6th, 2010

A friend from Studio Saraceno called because some solar panel mirrors had to be assembled here in Berlin. Those are actually large frames with solar panel foil behind a glass coated with some reflecting film. Inside the frame is a battery thats loaded by the solar foil and provides power to load cell phones and such. Looks quite nice but the efficiency is greatly reduced by the fact that the foil has to laminated to be applied to the frame without folding and breaking. The film on the glass further reduces the amount of UV light that reaches the foil. since we worked indoors there was no way to do some measurement.

the solar foil

the mirror

To apply that film they extra sent the stuff from Frankfurt to Berlin, but apparently the guys who did it here didn’t do their job too well, judging from the scratches on the glass and dirt behind the film. There seems to be some kind of magic to it, since even the manufacturer of the film doesn’t seem to know how to handle this.

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Tech Stuff

November 3rd, 2010

My current task is to build some stuff for the Computerspiele Museum. Thats not as exciting as it sounds, however it totally fits to the stuff I’ve been doing over the last months. An interface/video player is to be controlled using a joystick while LEDs are lit correspondingly. Again, Christian was very helpful here and provided me with a basic idea, how to build this. The plan changed various times since at first I was told I had to work with 12V LEDs, no one knows why. That sounded easy at first because I thought I could simply take those LED clusters that replace common halogen lights. But it turned out that most of them are not dimmable, unless you take really expensive ones (~€ 30,-). So now I use 3W ones on a heat sink. looks quite nice.

I even found a shop to buy arcade hardware such as knobs, joysticks etc. Sure there’ll be more fun with that soon :-)

to illustrate the current affairs

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Back to School (on my own)

October 18th, 2010

Working with Christian on my “Diskokugel” I decided I need to earn more about the basic electronics behind it. In fact, since I started with the project I have already learned more about it than in my electronics classes at the university, but it all remains some kind of esoteric half knowledge when one knows nothing about the rules behind it. So I started to teach myself intensely, reading and doing tests at home.

I found an open book project that has written a complete compendium for electronics education in a way that is totally understandable and their website even provides tests and exercises to check on your knowledge. Awesome!

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PD and Arduino

October 18th, 2010

I explored some ways to use PD to communicate with an Arduino. There are wo ways to interact with an Arduio from PD: serial communication via the [comport] object and controlling the Arduino directly with [pduino] using the firmata firmware.

[comport] simply sends and receives serial messages. I found it a little difficult to convert those messages into the right format as to understand and further process them. The PD help file isn’t exactly helpful to that extend, but I found a patch called ArduinoPDMessageSystem that makes sense of the serial messages, even though I haven’t understood every objects function there yet.

So far, I have managed to send messages to the Arduino to interface a HCF4094 shift register controlling 8 LEDs. I use the same register to control my “Diskokugel”, so heres for the next step to its completion :-)

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Crazy AV Machines Workshop

October 4th, 2010

The past week I participated in a PD workshop run by Oscar Martin and Luca Carruba at NK gallery. The workshop lasted one week and ended with a collaborate performance where all participants used their patches made during the workshop. I can’t tell you how that turned out because unfortunately I had to leave two days early to finish another job. However, the workshop was quite inspiring. Oscar and Luca rushed us through the possibilities of the software so fast that I imagine it hard for an actual newbie to keep up. For me it was quite informative, especially since I had my own agenda, wanting to know how to communicate with an Arduino with PD as means of an interface.

I’ve worked with Max/MSP and VVVV before and also had a look at JMax and PD back in 2002. PD has evolved a lot since then and since it is a piece of true open source software it has all my sympathies. The community is active and I´ve found the mailing list extremely patient and useful.

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