Studio Contrechoc

art & textile & technology entries

Victory over the Sun version 1.0, design and energy considerations

Second version of the Victory over the Sun project.

After the sketch version (see post the recycled jeans dress is totally modified. The front is reordered in horitontal strips, where the big LED’s form two curved lines. These 8 LED’s plus one at the bottom will  report about the game between the solar cell and the dynamo which is operated and powered by your hand and arm.


The back side is decorated with a pattern using the laser cutter.

vic3 backside

The material is recycled jeans. The idea is that there should be a match between the concept of energy generating and the material that is recycled. The jeans were worn for a few years and the worn out parts were removed. From the left over parts, which seemed still ok the dress was assembled. But in handling the fabric it was noted that also the seemingly good parts were deteriorating fast. In total contrast with the energy of course. Energy is energy, even if it is transformed many times. There is no comparison between fabric and energy, although we humans tend to associate green, “nice” energy with green recycling of goods and fabrics. Our tender ideas are not appreciated by reality.

The electronics is improved after the first skethc version. The LED’s are extended to 8. In the dress there are 9 LED’s. The two bottom ones will be used to indicate that a game is going on.


Inside of the dress, connecting the LED’s. The parts of the electronics, LED’s, circuitry, supercaps are all connected using connectors, so that testing is made easier.

In the electronics the supercap of 1.0 for each of the participants was replaced by two supercap’s of 10F at 2.5V in series. Now a player has to work to get to 5V!

One problem remained and remains. After the game a lot of energy is stored in the supercaps of 10F at 5.0V. You can calculate this energy: the formula is Energy of a capacitor = .5*C*V*V.

See for instance:

This means 125 J. In the first version this was only 12.5J because the Cap was 1.0F instead of 10F.

After the game this energy has to be dissipated to start a new game. But this getting rid of the energy costs time. The first try was using a ventilator. Even a cooling ven for a computer running normally at 12V could be used and took minutes to get the voltage of the supercaps down.

vic5 The ven is visible at the left bottom.

The last experiment was to charge the lipo used for the circuitry of the game.

During dissipation the voltage of the supercaps drops from 5.0V to hopefully 0V. The lipo battery is between 4.1V and 3.6V. So to charge the lipo a special LTC chip is needed (LTC3105) , to keep the voltage at 4.2V during charging back the energy of the game into the lipo. This LTC is actually a harvesting chip studied during a research on energy harvesting:

So the supercap should be connected to this chip and the output of the chip fed back into the lipo.


Expected was a fairly normal exponential behavior while discharging. Not quite so!

This is a typical graph of the Voltage over the supercap and the charging current to the lipo:

Screen Shot 2015-04-06 at 19.55.27

The time axis is not linear, noted were values of tens of mA of current and the corresponding remaining Voltage over supercaps. The LTC3588 took care of keeping the charging voltage to the lipo n 4.5V, even till the supercaps were at 1.5V.

There is a spike in the middle of the graph which was reproduced.

The drop-off is not exponential, probably because the charge pump is being cleverly regulated, this LTC 3588 chip is fairly complex.

The discharging is made interesting, but the last problem remains: the charge on the supercaps will not be brought back to 0V, which is the ideal starting point for the game. On the other hand with the 10F caps, the game takes long enough for the human arm to get tired. So maybe we keep this way of discharging.

One might get anxious about the lipo. If the lipo is charged to quick, things may get nasty. But the voltage of the lipo changed during charging only 1mV, from 3.81 to 3.82. The energy density of the lipo is far more bigger than the supercaps:

Lipo battery of 1400mAh * 3.8V = 3600 * 1.4 * 3.8 =~ 19000 J. So the 120 of the supercap does not really impress the lipo.

Adding an oscilloscope picture:


Yellow line: voltage over the supercap,

Blue line: inverted voltage over a shunt of .5 Ohm. For a square this means 10 mA. Maximum current 24mA. The current is different from the former graph because of the shunt

Start: first 4.9V being above the voltage fed to the lipo 4.2V (so the chip DC-DC downwards), then you see the crossing of this set voltage, the chip has to DC-DC upwards to 4.2V, there is a discontinuity, the current delivered is bigger -more efficent? After that the exponential. The last part is still interesting, the chip really keeps the voltage up to 4.2V while the supercaps ar at 1.5V.

Bremen Presentation pieces

At the Dutch Koningsdag event – Bremen version, one day later than the Dutch version – 10 pieces of Dutch interactive clothing will be shown during a meeting of Dutch citizens working in and around Bremen.

Five pieces of Contrechoc will be shown together with 5 pieces from Marina Toeters,, during the meeting “koningsdag” in Bremen in the entrance hall of the Hochschule für Künste Bremen.

For the presentation in Bremen these 5 wearables (Contrechoc) are chosen:

  • Solar Rim Dress, 2014
  • Super Nova shirt, with added data trousers, 2014
  • Social Wind, 2015
  • Je Suis, 2015
  • Victory over the Sun, 2015

Solar Rim Dress and Super Nova shirt are datavisualisations. Je Suis is a hacked dress. Social wind is a humoristic comment on a cooling wearable and Victory over the Sun is an artistic research result.

Solar Rim dress show the actual activity of the Sun, on the rim. The 64 LED’s are placed in a circle on the side of the dress. On the dress itself some loop structures refer to the shapes which are created by magnetic fields on the Sun.

The Super Nova shirt shows the observed supernova’s of the first half year of 2014 displayed on a printed picture of the Micro Wave Background radiation. The Supernova’s are displayed in a time sequence. The flashing clearly shows “the code” of the stellar explosions. Added to the t-shirt are trousers which show the data in a printed version.

Social Wind is a jacket which is made in bright yellow fleece. The back is open and 5 ventilators are rotating gentle at that side of the jacket when the temperature inside is to high or the humidity exceeds a certain value. The Social Wind jacket is a wearable reaction to a cooling dress of

Je Suis is a hacked party dress. The text is a reduction of the “Je suis Charley” protest. When the dress is approached 5 small plates with four versions of  “Je suis” and one image version of “the hand of God” in a retro style are lifted and hidden again.

Victory over the Sun is the result of an investigation into energy harvesting. The piece is a game wearable. The game allows for two ways of energy generations to compete with each other: one solar cell against your muscles. LED’s indicate how the Sun is beaten (or not) by your muscle power.



From left to right:

Solar Rim Dress, Victory over the Sun, Social Wind, Je Suis, and Supernova t-shirt with data-trousers.

You can find more info on these wearables in other posts.


2015 NASA App Challenge

Two years ago we participated with friends in the 2013 NASA App Challenge with a wearable. Last year we did a game for the 2014 App Challenge. Now we do another wearable challenge in the 2015 NASA App Challenge:

This is the first time we really try to make “intelligent” garments. We will integrate a neural network in the wearable. This network will “learn” by trying to recognize patterns. This learning will be made visible by changing the shape of the wearable, or even morphing.

The neural network will be small, and the learning capacities will be very limited, but this is a start at “really (somehow) smart” fashion.

Details about this project can be found in this hackpad:

images will follow next week when we try to finish two wearables in one weekend, where normally it takes about a month for a wearable…

But now we come with a group of expert programmers, designers and e-textilers, together with a car full of equipment…

(Making tags for this post … nearly all tags created for this blog are indicated, which means that something will be happening!)

Project page:

Supernova t-shirt with trousers

The t-shirt showing the sequence of observed supernovas of the first 6 month of 2014 was first shown at Paillard in the summer of 2014 during the exhibition Cuvée at Paillard.

Recently trousers were added with all the data which are used engraved with a laser cutter on the fabric of the trousers.

The idea of adding the trouwers is to show the contrast between “raw data” – as text and number items,  and this way of visualising the data of a time sequence on a surface area.

So the supernova observations with coordinates and time and date indication are shown as blinks on the t-shirt and as text on the trousers.

In discussions it appeared that the meaning of the blue/green ellipse on the t-shirt is difficult to understand if you are not a little bit into astronomy. For most people it is possible to look at all the countries of the Earth mapped on one page in an atlas, but the idea that the whole sky is projected into one ellips is not easy. But of course this is the same transformation: the surface of a sphere is projected on a plane into an ellipse. We know that the Universe is “space”, but we percieve it as a sphere, because the distance of the objects in space is so large compared to what we as humans are used to.

This blue green ellipse on the t-shirt is a picture of the Microwave background radiation. This represents the distribution of mass just after the Big Bang (well 350.000 years according to the theories).

On top of this – or rather through this picture – are the observations of stars exploding in the universe. We can see these explosions which are really far away because for some time these stars are as bright as galaxies. So you get a comparison between stars exploding and the ancient mass distribution. Stars like that (very big compared to the our Sun) have a short life time (compared to our Sun). They will end in an explosion after about 10 million years. So these explosions are like leaves falling of a tree, the tree representing the universe. And of course these observations revealed that apparently the Universe is expanding in an accelerating way, indicating that the law of gravity is not the only long distance force…

Back to the wearable, some pictures, textual data on the trousers:

su3 su2 su1

The engraving, done with a laser cutter, is perforating the very light weight fabric, which is not really fabric for trousers, it was chosen more for having a nicely colored surface. (Next time, better fabrics!)


Under the t-shirt is the electronics. Five big led panels are playing the part of exploding stars. The sky is divided into 5 big area’s, for the 5 panels.  The voltage used for the led panels is 12V provided by 3 lipo batteries in series.


The datavisualisation as a time sequence can only bee seen in a movie:





Change Partners

“Change Partners” is a small wearable presentation piece which warns you if 5 minutes are gone by in a conversation with guests talking with each other during a reception. If you want to connect to as many people as possible the conversations have to be limited and you need a chance to switch to other people. The problem is often that if you have a fine conversation, before you know it the two hours of the meetin are over. Good conservation makes time fly. Also people tend to talk to friends all the time, preventing other contacts to happen.

This knitted wearable can be worn in a simple way around the neck.  It has a timer which can be activated  by touching the two grey knitted area’s at the left and right side.

The activation makes an LED shine red, meaning that you are occupied for 5 minutes. After 5 minutes a green LED will indicate that you are free for a new conversation. When you are free for too long, there will a vibration from time to time warning you that you have to find a new partner for talking. A butterfly in front of the knitting is blinking indicating that the device is functioning.

The knitting:


Knitted band on a double bed Brother KH 940

movie domonstrating the use of the two knitted conductive area’s to get the signal for the timer to start the 5 minutes:

Knitting pattern

  • setup:
    8 needles main bed, 8 needles lower front bed
  • start double bed 1 tour, start with normal thread
  • then round knitting bed setting
  • 50 tours round knitting
  • 1 tour double bed as a marker
  • 110 tours round knitting
  • then switch to conductive thread,
  • 15 tours round knitting
  • switch back to normal thread
  • 450 tours round knitting
  • then switch to conductive thread,
  • 15 tours round knitting
  • switch back to normal thread
  • 110 tours round knitting
  • one tour of double bed as a marker
  • 50 tours round knitting
  • then all the needles of the lower bed where transferred to the main bed
  • then one tour with tension 10 and do the crochet knit stitch to make a nice finish

After that: knot wires to the conductive wool parts, knit the wires through the round knitting to the end parts. Insert the green and red LED’s into the round knitting. Solder the wires to the PCB, stick the wires for the butterfly through the end part and solder these wires to the butterfly. Sew the end parts together with the electronics inside.



The grey area conducts electricity. Knitted with conductive wool.


The electronics:

  • microcontroller: ATtiny85
  • 2 LED, bright red and green
  • Coin cell battery holder, 3V coin cell
  • Wackle motor
  • Gadget butterfly
  • on//off switch

The script can be found here:

and at Github:






Je suis – project

From the “Je suis Charlie” quick hack ( after quite a lot of modifications, this post provides some documentation of the “Je suis” project.

The project name has changed from “Je suis Charlie” to “Je suis”. In the idea of defending our “sacred” European civilization by joining in with the public outcry around the events in Paris this Januari there are too many issues – if you think about it.

Engagement is tempting but in the end individuality and doubt get the upper hand. Do we defend our freedom of speech and cartoons by necessarily offending others? On the other hand do some killer madmans – probably with some brain defects – defend their civilization by taking a gun and shooting around? Neither seems likely.


Therefore the essential “Je suis” is retained. This is an enormous shift in meaning!

Not the “I am because I think”, just the “I am”. Whatever that “I” is – whatever “being” is. Thinking closely to a text always dissolves the meaning. Individuality, supposedly developed during what we call the Renaissance is diminished paradoxically by all the “sharing” and copy pasting of the Web 2.0 and “social media” anyway.

Back to the project.

Temporarily showing “Je suis” is funny because this is the way thinking about individuality or the “I” works. Most of the time you just don’t think about it, sometimes it pops up. This voice inside our head, is it the “I”? And even when it is, why does it think it is different from  “the others”. Better? Worse? If the “I” pops up, it is only confusion. You seem to be “a thinker” if you state a blunt theory about this confusion, like “I think therefore I am” or “Sein und Zeit”. But how can just one voice inside a brain superimpose a static local idea on this evolving humanity of milliards of other voices?

The shift in meaning retained the idea of “content”, which is lacking most of the time in wearables. Combining design and interaction is already difficult enough!

So the “Je suis Charlie” flat 3D prints were replaced by “Je suis” 3D prints. In the middle the two hands, reference to the hands of Michelangelo…but in an 8 bit version! Which seems appropriate for our primitive understanding of the “I” and being.

The cord and the clips were discarded. The clips provided weight, needed for getting the plates down again. With just a cord the plates where not pulled down. The solution was to use a string of beads. This necklace is also a “normal” accessoire used in combination with this type of dress.

To pull the plates up, some mechanical problems ad to be solved. The part had to be attached to the dress to give it a rotation point – there was a black slip providing for the necessary frimness under the fragile upper layer of this party dress. And there had to be some distance from the end of the plate that is to be lifted to get an “arm” to work with. This was done with a small part 3D printed:

Screen Shot 2015-03-22 at 16.04.29

The angle to the horizontal and the grip on the beads of the neacklace proved essential for a proper lifting.

At the back the electronic was fitted to an acrylic transarent plate with two holders over the shoulders: (this part will be renewed by a shape done with the lasercutter)

2015-03-22 15.28.28

The electronics remained the same, there is a distance sensor which triggers lift of the plates by a stepper motor at the back. For presentations there is a special button for immediate action.

The beads were making the lifting a big job for the steppermotor, so the voltage for this motor was increased to 7.5V, two lipo’s in series. The AT328 is protected by a 3.3V Voltage regulator.

Most of the wearables hide the electronics. In this project about “je suis” it seems right to show the electronics, although on the back. You can watch the stepper motor pull physically at a cord to reveal the “content”.

A small demo movie sketch can be found here:

2015-03-22 14.48.02

Victory over the Sun – (sketch version)


This wearable is part of a research into energy harvesting, which can be found here: (Slow Raspberry pi server!)

The purpose of this wearable is to compare two sources of energy, not just showing a charging wearable.


The title of this project has changed a few times:

  • 1. Not another solar dress
  • 2. Energy battle dress
  • 3. Victory over the Sun

The first title is indicating that this project is not another mobile phone charging wearable. There is a solar panel, but also a hand crank device in the dress. But it is not about charging anything, because charging from a wearable is anyhow not very efficient.

The second title is indicating that the purpose of this wearable is comparing two sources of energy together in a game. The two source compete against each other. Which one will win? The solar energy or the muscular energy?

The third title is a reference to the oper of the Russian avant garde in the Bauhaus time:

Malevich and El Lissitzky made this oper famous, contributing to the stage design and the graphical displays.

There is some sarcasm in this third title, because it is rather impossible to win from the Sun in this game, only at night you have a chance, the solar panel is even charging slowly in normal daylight without direct sunlight.


Appropriately for the material old discarded jeans are chosen. Thus the material is recycled. The wearable is a simple dress with possibilities to add panels and the hacked Ljusa hand crank.


From the parts of jeans which were not totally worn out pieces were cut and these pieces were sewn together. An interesting folding problem popped up which will be described in another post.

Picture of the wearable in progress: (The hacked Ljusa, with the white card board and the red crank will be redesigned and more properly inserted into the wearable of course)

2015-03-12 07.51.57#1

Wearable made of recycled jeans material.


For the hand crank I have chosen the Ljusa of IKEA, which is a toy generating some power. It stores the power too in a 1.5F supercap. The second source of energy is a solar panel. Added to this is also a 1.5F supercap. With a ATtiny85 and 8 big LED’s – 4 LED’s for each energy source – the winning source can be made visible.

The electronics idea was to show the current Voltage for the two sources in two rows of 4 LED’s. The microcontroller which can just be used is a ATtiny85. Two analog PIN’s and two PIN’s for a multiplexer chip. One PIN is left for one other purpose.

Although the sources are generating energy, there has to be another energy source for the microcontroller at the moment. It would be an nice idea to have the sources (solar and muscle) first generate enough energy for the game to start, but this has to be figured out yet.

The third energy source is a rechargeable lipo battery.

Then there has to be a discharge for the game to restart. This is done using a FRT5 DC5 relay.

The number of difficulties in the electronics were plenty: besides the usual stupid mistakes like connected the LED’s the wrong way there were a few real “Zen master” problems (which means you have to learn something besides correcting stupid mistakes).

The ATtiny85 uses USI instead of SPI, code for this was found at:

Then the implementation of the use of the analog PIN’s proved time consuming. In the end the soution was found in connecting the PIN’s to the GND using a 1M Ohm resistor.

Then the coding of the LED’s, in two groups of 4 inside the bigger group of 8 was proving not straightforward. Apparently the number read using the ADC code is not a “normal” INT number and you cannot use all math available, like subtracting 512 from the value read between 0 and 1024.

The final code can be found here:

Testing pictures of the electronics:

Testing is better down as much as possible outside the wearable. In the end the electronics is on the board and the ATtiny85 had to be removed and placed in the programmer breadboard way too often again, I could have better soldered programming the wires to the board right away…

  • testing first the ATtiny85 and multiplexer on a breadboard
  • testing the LED’s on a piece of jeans
  • the PCB with the supercap, multiplexer, relais and ATtiny85

2015-03-16 08.09.00 2015-03-16 11.18.50

2015-03-17 10.38.49

Remarks about the PCB:

  • One relais too much, two components right upper side FRT5!
  • At the left side the two energy sources can be connected.
  • The green component is the 1.0F 5.5V supercap
  • The Ljusa has it’s own supercap (storing energy), the solar panel uses the supercap (green thing) on the board.
  • Middle under, ATtiny85, left under hd74ls164p shift register
  • The PCB can be redesigned more efficiently!

Preparing Knitting Images

Documentation for a workshop “Machine Knitting” at In this workshop we will explore possibilities of tuck, skip, lace, Jackard, and other knitting techniques. In former blog posts is documented how an image is uploaded using my own software together with the board made at a session of in Bruxelles.

With an accessoire it is possible to knit with different colors using the double bed.

2015-03-01 15.25.36 A so called color changer.

The way to knit an image in a double layer, avoiding the loose thread of Nordic Knitting can be seen in this video of the Japanese knitlabo: (Double bed jacquard knitting)

Using the Due to transfer the images and not the img2track (see below) the procedure of sending the right image had to be found.

2015-03-01 15.25.44

After the normal setup of the double bed the settings are:

Main bed slider: both PART buttons,KC(II)

Double bed slider: left PR slider, circular knobs press and turn, bottom lever: center.

2015-03-01 18.53.17

But just sending the image as done in other posts, like the single bed TUCK, slip, lace and Jackard is not possible.

Exploring the patterns stored inside the KH-940 it could be seen that knitting from right to left prepared the pattern at the top side of the needle board (first bed), while going from left to right stayed on this line. The second color did the reverse in color: the “black” in the pattern was at the bottom side of the needle board, and maintained while knitting to the left.

So this meant that the “pixels” of the image should be twice as long (two tours of knittings), but also that the tours (of left and right) had to be alternating in base-color.

The prepareation process can be shown in these images:

Screen Shot 2015-03-01 at 14.06.54

Normal image, the pixels are two high, which still gives half height as shown below. So multiply again by 2 (Using the setting “Nearest neighbor – preserve hard edges” stting in the scaling menu of Photoshop.)

Screen Shot 2015-03-01 at 14.07.06

Making the image 4 times the height, 2 x 2 pixels in height.

The next step is making the lines alternating in base color. I used for this a second layer with black lines of 2 pixels high. These pixels were selected and with the selection the alternating horizontal lines of 2 pixels were inverted:

This resulted in a real “encoding”, the text cannot be read anymore:

Screen Shot 2015-03-01 at 14.07.53

Using this in the Processingg sketch and sending it to the KH-940: (horizontal direction inversed)

Screen Shot 2015-03-01 at 14.11.15

This result was knitted: (the knitting is one layer thick, front side has the image, back side the stripes.

2015-03-01 15.26.02

The reason to mutliply by 4 and not 2 is because the setting is the PART mode, with one tour knitting, you knit only half. If you multiply just by 2, you get a diminished height:

2015-03-01 15.26.08

As can be seen, the bind off isn’t really perfect. The trick for binding of is to switch to another color, knit this color further in round knitting, getting the knitting of the machine and crochet the stitches together of the last row of the knitting. Then get rid of the last color. In the references is the video.


one bit images

around the Jacquard:

double jacquard:

Software: i use my own program (Procesing sketch and Arduino Due code), and having this fun of discovering the image encoding, but you could also use img2track, like in the video, this uses the adafruit hack to transfer images, free for max 100 needles.

Binding off:

Solar Wind: script and testing hardware

Specs hardware:

Ventilator motors: 5  – 3 phase motors, running (just) on 5V, also on a fully charged lipo.

Microcontroller: atmega328P


  • DHT11 temperature and humidity sensor
  • LDR, light value sensor
  • push button

Battery: lipo 14oo mA

Lipo Charger included.

On off switch, between lipo+charger and the microcontroller.

Script: made in arduino environment

The 3 phase motors are driven by making the PIN’s go HIGH LOW like this:

the voltage of 4-5V and the current provided by the PIN’s seems to be enough so no ULN is needed in between the PIN’s and the motors.

Microcontroller PIN‘s:

  • 2,3, — 17 —,  ventilator 1
  • 5,6,7,   ventilator 2
  • 8,9,10,   ventilator 3
  • 11,12,13,   ventilator 4
  • 14,15,16,   ventilator 5
  • 4, DHT11 PIN
  • 18, pushbutton PIN: to control the modes of the script.

Executing Modes:

  1.  always on: 5 ventilators are running alternating thr direction
  2.  LDR mode: ventilators run when low light value
  3.  Temperature mode: ventilators run when the temparature is above 21 degrees Celsius.

The modes are mode for presenting and testing. With the pushbutton the different modes can be selected. The LDR mode is nice to show an emmediate effect.

Script testing:

On a fully charged 1400 mA lipo (3.7V) the script can run in mode 1 (always 5 rotating ventilators ):

more than 7 hours, after 8 hours the rotating is visibly slower, but still moving…

2015-02-12 13.53.51







Social Wind: development of the yellow motor holder

The 3D printer allows to make a nice connecting shape between the textile and the electronic hardware. For “Social Wind” i have chosen  3 phase motors:

2015-02-09 19.15.03#1

The problem (in the old days) was how to sew the motors inside the jacket. Nowadays this is not really easy using the 3D printer, because you have to print quite a lot of tests, but you arrive at a nice holder of the same color as the fabric – or the color you need.

The cooling effect comes from ventilators, not for example Peltier elements. The ventilators provide a gentle cooling effect and are at the same time a nice moving shape. The Peltier elements would be inserted in the fabric and not even visible. This leaves absolute freedom for the design, but hides the functioning.

The development of the shapes to hold the motor in this jacket can be seen in this picture of all the shapes printed for these 5 motors which will be sewn in the jacket:

2015-02-09 19.12.56

First I tried to print the whole ventilator as one piece. No doubt with an expensive 3D printer this could be done, but with my terrible ROBO printer a better option was to print the axis and the blades seperately.

2015-02-09 19.15.48

Because the five ventilators will be running close to each other, the ventilators rotate against each other. This has to be tested first:

Later on the axis were made higher and lower, so the ventilators could run close together.

All the five attached to the microcontroller:

The motors run at 5V which is probably too low. So the power of the motors is big enough for small blades, but these blades are to big if you start right away at a fairly high speed. The solution was to start slowly and build ip momentum. Then the motor can rotate these 5 blades without a problem.

The STL files will be available soon.














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