Studio Contrechoc

design & textile & technology entries

Monthly Archives: March 2015

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 fromĀ  “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)

(see for a more advanced 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: