Studio Contrechoc

art & textile & technology entries

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.













Social Wind – first sketch

First images of the Social Wind Design. The idea came from the Warming Dress, see former post

This design called “Social Wind” in a (humorous and friendly) discourse with Warming Dress will become a cooling jacket. The material used for the jacket is fleece, color bright yellow. The basic building shape of the jacket is a trapezoid. Five are used for the conic shape under the middle connection and 5 are used for the top shape. Completing the 3D shape of the jacket are the two shoulder pieces, on top of this jacket shape are two long collors, which run along the neck to the middle, providing stiffness and at the same time pockets for the batteries. The sleeves (inspired by the sleeves used in the Middle Ages which were also used as pockets) are made of two half circles folded open. Theses sleeves fall open to the front and provide space for the small microcontroller (the arduino used for testing the motors will be replaced by a bare bone atmega328 or 5 attiny85 and a central unit with a RF12 transceiver) and the interface for the wearer.

The back has an open strip. Over this strip holders will be attached for 5 small motors that are printed of yellow PLA. The 5 rotors blades on the axis of each motor are leave like.

The motors are so called 3 pahase motors, that means that they can be driven using 3 wires. The script for the motors is fairly simple, the schema presented in this post:

was used. The 5V from the Arduino (in test setup) is probably a little bit too low for these motors, so the script uses a slow start up. For small ventilator blades starting at higher rotation speed wasn’t a problem, but with the bigger blades apparently the moment of inertia was too big. Starting with a slow rotation solved this problem. All the electronics will be gathered in a speical pocket which can be easily removed after discarding the jacket.

Printing the parts between the electronics and the fabric was another detailed process, besides the sewing of the jacket.

The rotor blades are printed as parts, not as a whole shape. The 3D printer used didn’t produce a nice shape if this ventilator was printed as one form. Making 5 blades and sticking these blades in a central axis is more efficient. More details about these 3D prints will be given in another post.


The yellow color of the PLA exactly matched the color of the fleece fabric, the camera is unable to show the exact bright, nearly fluorescent color of the fleece and PLA>

Many details still have to be solved, like the buttons, closing the jacket in front, wiring, designing the interface. There will be 5 ventilators at the back. The ventilator structure in front has to be designed.

2015-01-27 10.47.12 2015-01-27 10.47.30 2015-01-27 10.47.45 2015-01-27 10.48.02


Spine Warming Dress Poster in Textile Museum, Tilburg

During an expert meeting in the Textile Museum Tilburg, there was a presentation of CRISP.

One of the posters was about the Spine warming Dress. Marina Toeters designed this dress and Contrechoc did the circuitry.

2015-01-21 16.25.15

2015-01-21 16.26.14

2015-01-21 16.26.03


Je suis Charlie

Of course! (You thought e-textiles is not political?)

Just a “quick” hack: (well in the end it will be 2-3 days of work anyway…)

From a discarded party dress, some steppermotor and a distance sensor, together with some flimsy 3D prints with the simple text “Je suis Charlie”. This experimental e-textile group joins in.

The dress from a friend in Bremen is having horizontal strips of fabric. Ideal for the purpose of this idea because these strips can be lifted. If the strips are lifted the backside of the strip is shown, and the text appears.

2015-01-11 13.29.40

The hardware to do the lifting is a stepper motor, which is attached to the back. It has to be sturdy to lift all this fabric. A distance sensor is driving the interaction.

First the text on the 3D prints consisting of up to 3 layers of PLA: (they will be all bright yellow in the end result)

2015-01-11 13.14.06 2015-01-11 13.14.11 2015-01-11 13.14.17 2015-01-11 13.14.26 2015-01-11 13.13.57 2015-01-11 18.57.55 2015-01-11 18.59.04#1

The top of the dress is made more smooth for the wire to run over it by a plastic covering, the yellow band is at the moment holding the motor at the back, will be replaced… (lot’s of details even in a quick hack).

2015-01-11 18.47.38

All very simple, but for a few details…

The hardware is just hardware, it is not concerned about the world and won’t cooperate. Otherwise stated: if you have an idea thought out, and it has a nice purpose, this doesn’t mean that you (yourself) make the right decisions about the hardware and programming.

So although being politically involved we had to debug. Do you mention the debugging in this kind of posts?

———Skip this part if you are in politics only!————->

The setup was working when hooked up to the laptop for uploading the script. But running from an adaptor the distance sensor got mad and always fired the steppermotor.

2015-01-11 18.20.05 2015-01-11 18.20.17

Measuring voltage and current a strange thing was noticed: the current consumed by the motor was 0.1A when running, but after stopping it consumed .25A. So the stepper.h (default arduino script)  had to be mended:

after “a step” in the function void Stepper::step(int steps_to_move) of the normal Arduino script “Stepper.h“, all the PIN’s must be set to LOW:

digitalWrite(motor_pin_1, LOW);
digitalWrite(motor_pin_2, LOW);
digitalWrite(motor_pin_3, LOW);
digitalWrite(motor_pin_4, LOW);

to reduce the current to normal levels after stopping. That this is not done in the scrit is surprising. It means that some of the coils in the steppermotor are left with a voltage, and since the coils have a low reistance, the current is high – and waisted!

2015-01-11 18.20.43

But mending this first feature didn’t fix the weird behavior of the sensor. So we tried a capacitor over the Voltage from the adaptor. A capacitor of 470 microF solved the problem. Apparently this adaptor (see pictures) is not very stable.


Pictures of the distance sensor, stepper motor, capacitor which saved my day and the wicked adaptor: (all at the back of the dress on the dummy)

2015-01-11 18.21.37 2015-01-11 18.22.05

The script is a combination of a stepper motor example, combined with a “NewPing” distance sensor. If you are interested, you can download the script and play on:

For printing the flimsy 3D prints I was using a setup described here in Dutch:

This way of making relief printing will be described more in detail in another post.





Knitting around a corner

The knitting produces a flat surface in principle, you can make a knitted 3D shape because you can fit shaped parts together in making just like a dress with woven cloth. Knitted surfaces fit more easily because of the stretch property of the knitting.

The 2D knitting surface is just a rectangle of knitting needles and tours, width x height.  Thus 2D property of the surface is just the most basic possibility using B and D positions of the needles. Using the E position of the needle and the H mode of the slider you can vary differentially the number of knitting needles over the surface and create in the surface itself tension. This tension makes 3D shapes inside the knitted surface, which can create pockets or bends. WIth this technique gloves are made, the boxes of the last post.

2014-10-30 10.08.11  2014-10-30 10.08.00

The E position in action on the knitting board:

2014-10-30 21.23.31

The threads comes back behind the slider over all needles, but before returning you have to put the thread under the last needle. Slider at far left, will be coming to the right.

2014-10-30 21.23.15

To diminish the needles in E position you have to put this needle in D position. Slider is at far right will be going to the left and put this D needle back in B position.

2014-10-30 21.23.01

Differentially knitted tours, so you have to keep pulling the knitting down, replacing the weights all the time.

2014-10-30 10.08.25

Two examples where you start knitting tricot normally, then put all the needles in E psoition and work your way back needle by needle to the B position. You see the knitting makes a angle, start of this knitting was right side.

2014-10-31 08.16.12

The same with yellow lines indicating 10 tours, this knitting was started at left, for 20 tours then you can follow from the corner middle left upwards to the right.

2014-10-30 10.08.30

This knitting is made making 10 tours of normal tricot, left side, now deformed into an angle. Then put all the needles in E position, but for the center 2 needles. Then every tour putting the needle oposite to the slider in D position. The extra tours are starting small in the middle and growing wider as more needles are knitting again. This shape as shown  in the picture is totally stretched, normally a 3D shape.


Learning to make a thumb-box: 親指ックス手袋の編み方

This title part in Japanese is no doubt totally wrong :-)

I saw this youtube movie: and tried it out, only not for my sock, which is indicated in the title ( 足袋ックスつま先の編み方, means the way (方) to knit (編み) toe (つま先) boxes (袋ックス) for foot (足)). I just made this box thing and it turned out to be one third of a glove. I made the Japanse title up for this knitted thumb box.

Although i am interested in, and aiming at datavisualisation in knitting, the way to improve technical skills is to do simple exercises. It is clear to me that this knitting device is far more than a “mirical knitting printer”, with one button and pushing this button makes a perfect copy.

So for the material of this post no Arduino Due was used at all, the tricks were in using hand and braincells, closely observing seemingly unimportant details, which naturally turned out to be very important…

A few lessons were learnt. First that I started with thread which was too thin. It broke several times:



Not even all the disasters are shown. The good thing of knitting is that you can recycle the thread after a knitting disaster. The idea that you only waste (called learning)  time and not material (eg in 3D printing you cannot put the PLA back) is rewarding, even if the thread costs nearly nothing.

Then that in the H mode ( needles totally sticking out are kept on hold) you have to start with putting the needles in the E position at the other side of the slider, then go back (otherwise your thread is around this bunch of E needles)


Then after a few time with the thin yarn in the end knitting with a thicker thread,


all steps were taken, and although this was just a test, it nearly became a glove…


Some holes at the base are still a bit too big….

Practice again…..


  • Set up a normal tricot , 30 needles, 10 tours
  • from -8 to 8, insert thread to keep track of the start of the box
  • from left, put rest of needles at right in E position
  • after that from right the rest of the needles at left in E position
  • knit middle part 20 tours, carefully hanging a weight in this part
  • now from right, one needle -7 to E, knit, from left thread over this needle, at right needle 7 to E, knit
  • repeat until 4 needles at both side are in E
  • then retreat: from right put needle -3 back again (still winding the thread around the needle you come from), the same from left, till all the needles (-8 – +8)are back in B position.
  • Then from left, pick up at the left side of the box knit stitch number 3 (or 4?), put it back on needle +7, knit, the same at the other side.
  • You are working your way back up, closing the box.
  • If you do everything regularly, you won’t end up with the holes like me :-)
  • Look at the Japanese video for getting the idea.




Practicing my Japanese, knitting katakana

The Hiragana writing is easier for me to read than the Katakana…you meet Hiragana more often – as a beginner – and katakana is like isolated islands in the sea of Japanese. Added to that is the transformation of mostly English words into the Japanese syllable format. For me always a bit like a puzzle – in these words English is taken rather literally from the sound, not the writing – it’s punishing English for swallowing letters :-). Beside that, for me also always the r/l uncertainty… But slowly I manage…and than suddenly it helps when you are in a language area where the machines are Japanese, Brother, Silver Reed…..more reasons to practice.

So i am hacking the titles out of Japanese Youtube movies about knitting, scanning this Machinelabo site, making a Katakana list, improving again a little bit my Katakana reading fluency:-) – i’ll never be able to pronounce this in Japanese – the same thing with my pronunciation of Frenchified English words in French, just impossible to get this English right in this other than English language transformation…Isn’t language BIG fun!!!

デザイナ・ニット = Designa Knit. the software program for interaction with the Brother Knitting Machine
ブラザ = Brother – the brother knitting machine : ブラザー機 , (Brother has become something like “BU-RA-ZA”)
シルバー = Silver – Silver Reed knitting machine : シルバー機, (SHI – RI – VA – A, the -r/l thing)
ニット = knit, N(I)-ji -TO
パンチカード = punch card, PA – N – TSJI – KA – A – TO
テンション = tension
リーダー = reader, ニットリーダー = knitreader
パラフィン = parafin
ニットキャンバス = knit canvas
カウンター = counter

プレーン = plain
レース = lace
スレッドレース = thread lace
スカラップ = scallop, knitting in shell shapes, (i have to find this out)
ルームソックス = room socks
プレーンソックス = plain socks

and then there are some Kanji that stick out:
編み = amu, to knit
機 = ki, machine
編み機 = amuki, knitting machine
模様 = mojou – pattern
靴下 = kusjta – sock, or socks

general word list:
サイト = site
マニュアル = manual
ファイル = file
ページ = page
コンプリート = complete
コメント = comment
ツール = tool, but also “tour” – knitting line ?
スタンダード = standard eg standard version.
プロ = pro, eg pro version of software
コンタクト = contact
メールアドレス = mailaddress
メッセージ = message
ドレッシング = drssing
インスタントラーメン = standard ramen

Now this is a nice one:
マイペース = mypace, doing things in my own pace

Words that are in Katakana, but Japanese…
ビックリする, bikuri suru, to be surprised

Captura de pantalla 2014-10-21 a la(s) 09.27.27

Most of these words I found at: and checked if in doubt with Rikachan plugin and in Google Translate.

The mysterious KH-940 weave knit

One of the knitting techniques that was omitted from the list we experimented with uptil now (the skip, patent, nordic, lace and jacquard) was the weave stitch. Experimenting a bit with the weave knit was giving puzzling results. Most of the time this is frustrating, because it means this is going to cost time. On the other hand, if something costs time, it also means that there is something to discover…

I discovered that moving around at either side of the knitting on the knitting machine caused a needle count error, this is fixed now in the software:

(This still is the very basic software. No fancy stuff for an image moving in the Processing sketch when knitting a tour. If the image is too big the underside can even be out of sight. I am wondering about the possibility of having a choice between the different stitches, then give a simple analysis of the image, if this is the right image for this stitch…-possibility to get the inverse -negative – image or the mirror image. Even have an indication if the distribution of the pixels is fit for this stitch.)

The weave stitch is using the entrance of the slider, without being inserted in the first or second thread opening in the middle of the slider:

2014-10-19 09.23.27

The base thread (in the middle opening) has to be very thin and the tension is set to 1-2. The second thread has to be thicker yarn.

Because of the tension setting the produced knitted surface is about half of the image knitted: so starting with the normal dimensions

Captura de pantalla 2014-10-19 a la(s) 10.50.17  The white pixel is showing the thick yarn at the backside.

you get this knitting:

2014-10-19 10.47.11

This is the back of the knitting, that is why the letters in the image are mirrored. For this experiment, we used the MPPT graph again. Apperently, for the weave stitch the pattern of the filling is important. This has to be prepared in Photoshop using the (self defined) preset brushes and patterns.

Then the next step is to enlarge the image height. The graph has to be stretched in the image, to have it normally scaled in the knitting. You cannot use “free transform”, because this would destroy the fill pattern of the surface (although this sometimes gives ideas too). The rescaling has to be done by hand,

Captura de pantalla 2014-10-19 a la(s) 10.48.48

Also we varied the fill pattern of the surface. You already see that it is difficult now to keep the graph in the right shape.

This resulted in knitted weave images were not convincing, the graph appears, but only dim, the weave pattern inside the thin thread is not crisp: See here back (left) and front (right) side:


During knitting the thick yarn was changed three time, to see which would work best. Vertically up the thicker yarn was yellow, middle we used two middle thickness yarns – yellow and light pink- and below the thick plastic pink yarn also used for the pollution scarf.



Here the thicker yellow yarn and the double threads is displayed.

testing further:

Again changing the fill and also making the graph more clear, taking the brush of example 426 from Stitch World Pattern book: x00x00x.

Captura de pantalla 2014-10-19 a la(s) 10.48.59

Also changing the basic thin wire to even thinner (shining blue very thin yarn).

Starting of with the thick plastic pink yarn we wondered about the fact that the knitter was not at all complaining about the thickness of the pink plastic yarn, while the tension was set to 1. Normally for this yarn the tension has to be 9-10. Ok then try even thicker yarn, the bright yellow which we also used for the presentation “Yellow Things”. This was knitted on a knitter with much bigger needles and distance between the needles.

There was no problem knitting this thicker yarn and the image got out very clear now:

2014-10-19 10.33.04  front 2014-10-19 10.28.32 back (on the knitter)

This is the fron side of the image, where the thicker yarn is beautifully overlayered by a mesh of the blue thinny yarn.


2014-10-19 10.33.36 2014-10-19 10.33.41  2014-10-19 10.33.46  2014-10-19 10.33.10,

Details of the fill, the mesh formed by the thin blue yarn, the way the graph is showing in the texture. You can see how the thick thread is catched inside the mesh of the knitting.

This weave pattern begs for more experiments!

Finishing with the cones of the yarn side by side:

2014-10-19 11.31.10

When i looked back i realized the maybe it is not really the thickness but the relative textures of the threads…more experiments are needed.


Weaving the same image with a very thin plastic fiber. The ordinary yellow wool seems to be caught inside an invisible plastic mesh:

2014-10-19 15.43.41

2014-10-19 15.43.47

2014-10-19 15.53.12 2014-10-19 15.53.48

some details where the plastic mesh can be seen, and the side with the arched wires.

2014-10-19 15.44.59  the plastic thread used.






Knitting workshop during ArcInTex at TU/e Eindhoven

During ArcInTex  week on last Thursday there were informal workshop sessions at the wearable sensor lab of TU/e Eindhoven. Organizers were Dr. Tomico Plasencia, Marina Toeters and others.

My theme for one of these workshops was based on knitting experiments reported in this blog. The idea was to have a small group of participants experimenting on coding in knitting, in the line of this “from GPS to knitting” post.

To make everyone knitting on knittings machines without any introduction is a bit too much to ask for one afternoon, so I brought these Quick Knitting wheels. The challenge for the participants was to find out how to make a bend in the circular knitted tube which you can easily produce with these wheels.

2014-10-14 14.19.54 These knitting wheels found at shop ZEEMAN, all 4 for 5 euro’s.

The organizers quickly added a Silver Reed and a PASSAP knitting machine. The Silver Reed was extensively tried out by students from MICA Baltimore which were visiting the school where I teach (, and were also present at Eindhoven.


Also several circular hand knitting devices appeared out of nowhere:


circ6  circ5 circ4  circ3 circ2  circ1

The cbending hallenge was solved by several participants, here an “educational” example: (Troy made this)


While another participant made what even looked like a “glove”: (by decreasing to one peg, you get a point like bend)


This challenge was given with the designed GPS track in mind, when done in circular knitting this line requires bends to the right and to the left.

track-90 Figure: bends to the left and right are required for a 2D tube version of this track.

Starting real bending:

bend_1 bend_2 bend_3 Inserting yellow (thicker) thread between the grey threads to make a smooth bend. Half the ring was used for the yellow thread and then a whole ring of grey. Around 15 inserting tours of yellow was needed to make the corner. Because this depends on the thickness of the thread, a test bend is always needed to find out this number.

The double bed knitting machine can make “socks” and a bend to one side can be made ( but for the knitted GPS track “in 3D” we need also the other side bend, which on the knitting machine requires that you get the knitting of the bed, reverse it and knit the second bend – or so it seems…further research has to be done.

With the circular wheels you can increase and decrease at both sides without a problem, because it is done by hand anyway.

More pictures here:




Get every new post delivered to your Inbox.

Join 25 other followers