Difference between revisions of "Swatch Making"

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The script can be found here: ....somewhere!
 
The script can be found here: ....somewhere!
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== Joule Thief ==
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The Joule thief uses a boost circuit for making 3V from a 1.5V battery.
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The battery holder is using aluminium foil on fabric to do two things: it serves as a battery holder and it serves as the switch. The LED starts when the conductive pieces are pushed against the plus and minus of the battery.
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The schema for a Joule Thief can be found on many places, for instance: https://diyteach.wordpress.com
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The most tricky step is the winding and connecting the wires around the ferro toroid: here you find a clear image: https://www.instructables.com/id/Itty-Bitty-Joule-Thief/
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[[File:jt99.png|400px]]
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more info can be found here: http://interactionstation.wdka.hro.nl/wiki/Energy_for_Designers#Week_1_-_Day_2
  
 
== results - fabric and TFT screen ==
 
== results - fabric and TFT screen ==

Latest revision as of 14:31, 22 May 2020

in progress


intro

Making swatches for e-textiles.

The goal is to provide examples for simple and more advanced circuits on fabric.

The possibilities to make "soft" versions of electronic components like switches and battery holders.

Wm1.png The collection of swatches

preperation

Sm1.png

Table with tools

Sm2.png

Putting a special spool with conductive thread inside the sewing machine.

Sm3.png

Lock Machine

Sm4.png

Table with swatches

tools

Machines

  • Sewing machine
  • lock machine
  • soldering station
  • Knitting Machine
  • scissors
  • needles
  • stitch undo tool
  • plyers
  • needles
  • magnifying glasses

electronics

  • leds
  • coin cell batteries
  • TFT screen

microcontrollers

  • ATtiny85
  • Arduino Pro Mini

Sensors

  • light LDR
  • soft membrane
  • push sensor
  • temperature sensor
  • BME680 - gas, barometric, temperature
  • ADXL345 accelration

Special E-textile applications

  • knitted pull sensor
  • fabric speaker
  • fabric breadboard
  • lace
  • soft button
  • fabric folds
  • fabric screen container

led conductive thread connection

Connecting the legs of the LED to the thread is always a bit of a problem.

There is a method making an eyelet of the leg of the LED and knotting the thread.

I trepide out a new way for me, with a small clamp:

Sm5.png

Sm6.png

Sm50.png

materials

  • non conductive materials
  • conductive materials

Sm41.png

  • vlisofix plus aluminium foil


conductive threads

There are many different conductive threads. Some like the Karl Grimm silver thread can be soldered. Most others, which have a plastic kernel cannot be soldered.

Mm1.png

For using conductive thread in my Janome sewing machine I have to change the bobbin holder. I then can put the stainless steel conductive thread in the spool.

Mm2.png

All conductive threads have different properties. The most important property for the use in a circuit is the resistance. The resistance of a conductive thread can vary from very little (say less then 1 Ohm every 10 centimeters) to very high resistance, sometimes even kOhm or mOhm.

One of the swatches shows 6 different conductive threads.

Mm3.png

On school we only have the stainless steel, which consists of steel fibers around plastic fibers. When you wash this thread it gets corroded, and will break down.

Many conductive threads can only be bought industrially and are not available for small consumers.

It is interesting to look at the conductive thread under the USB microscope, then you get a better understanding of the structure of the materials and you can understand why some of these threads break down easily.

Mm60.jpg Mm61.jpg Mm62.jpg Mm63.jpg Mm64.jpg Mm65.jpg
conductive thread 1: Stainless Steel, 4 ply, the school material. conductive thread 2: Karl Grimm, can be soldered, silver, head to get, the least resistance conductive thread 3: Elinox, high resistance. conductive thread 4: Pes Det, the winding of the conductive metal is very conspicuous conductive thread 5: Wool NM 1013 + steel, lots of wool and the single steel fibers, in this sample most of the resistance conductive thread 6: Bekinox, feels very heavy
resistance: 5.0 Ohm per 10 centimeters of the sample resistance: 0.5 Ohm per 10 centimeters of the sample resistance: 90 Ohm per 10 centimeters of the sample resistance: 18 Ohm per 10 centimeters of the sample resistance: 420 Ohm per 10 centimeters of the sample resistance: 1.0 Ohm per 10 centimeters of the sample

The problem of the conductive yarn is that it is only available in industrial quantities. The only bigger spool for sale commercially (for us) is the sticky metal conductive: https://www.kiwi-electronics.nl/sf-dev-11791, otherwise you have to buy bobbins of 10 meter or so: https://www.floris.cc/shop/en/wearables/932-stainless-thin-conductive-thread-2-ply-23-meter.html

Copper wire

This is used for winding coils. It is isolated, although you "see" the copper. It is called enamelled copper wire. To be able to solder or connect this wire you have to scrape the enamel from the wire, using a knife or sand paper.

|SingleShot0032.jpg

The enamel and the copper can be seen in this picture. The wire in the coil had to be repaired, it had to be scraped to be able to solder it.

|SingleShot0039.jpg

The soldering material will only stick where the enamel is removed. Here the soldiered joint can be seen under the usb-microscope.

|SingleShot0037.jpg

That is why in a knitting of this wire, there is not a short-cut (if the enamel is not damaged).

links to shops: (currently...)

At floris.cc: https://www.floris.cc/shop/en/home/2105-conductive-thread-60g-stainless-steel.html

I bought the sticky conductive metal at KIWI: https://www.kiwi-electronics.nl/sf-dev-11791?search=conductive&description=true

I saw "anti static" and conductive wool at Bart and Francis: https://www.bart-francis.be/index.php?action=search&lang=NL&srchval=conductive

Failures

I especially also add the failures. Otherwise it would seem that everything fitted without any effort, which is not true. Sometimes failures are more interesting than results. Failures do keep you moving while results are finished - dead.

From these what we call errors you learn the most. For example, I thought I would get a better connection by making the stitch length smaller. But then the stitching on the heavy material gets irregular.

Sm10.png

That induced me making a swatch of the different stitch length. It turned out that the default stitch length of the machine 2.4 mm was the best. I also tried out some decorative stitches, and the zig zags.

Sm9.png

Starting to add embroidery, things got wrong. This is the material which reminds you of the difference between your lofty ideas and the materials. If everything would go smooth and without any hiccups, no jumps would be made, everything would remain the same. Jumps on the other hand cost time. Maybe time is being made by the failures and the jumps.

Mm52.png

Starting embroidery combined with conductive thread, things didn't came together...

The loop in the wire of the fabric speaker....somehow, in the middle of the windings, a loop was formed at the other side of the fabric, resulting in 2 cm of wire which had to be removed.

Coil-b.png

fabric battery holder

The last battery holder I made functioned, but is was also a bit inconvenient, because it was cumbersome to get the coin cell out. It was too stiff and has only one entrance.

Sm36.png

Therefore I designed another way, a battery holder with two sides open. The base fabric holds a pattern of conductive thread and is for the larger + side of the battery. The fabric on top has a nudge of conductive material that pushes on the - side of the battery. There is of course a loop going on the outside to the minus, preventing a short cut.

Sm37.png

nudge on top of the fabric made with a zig zag three times on top of it.

Sm34.png

With a needle the wire has to be pushed through the material, otherwise there will be a short cut.

Sm32.png

Placing the upper side of the fabric battery holder.

Sm31.png

The piece is sewn on the base fabric using a zig zag, so that we don't have to fold the side again.

Sm30.png

Connecting the wire to the wire of the circuit.

Intermediate stages

Because the sewing machine has a special spool cylinder for the conductive thread installed, the fabric battery holders have to be made later.

Sm7.png

Simple circuit, with one LED. The corner fold is the switch.

Sm8.png

Circuit with two LED's in parallel.


results - testing conductive thread

Mm35.png Mm36.png
The first swatch is trying out the conductive thread, as can be seen, in plain stitching, when the stitch length is too small, the stitch gets irregular at this fabric. Sample swatch for different conductive threads. Description above.


results - Swatches about circuits

Mm32.png Mm31.png Mm33.png
A simple circuit. In an electronic sense, this is very simple. For e-textiles, there are already problems to be solved, like sewing the conductive thread and the soft battery holder. A Parallel circuit. To be able to make two LED's shine, both LED's must be connected to the plus and the minus. E-textile problems: connecting the conductive wire by sewing. A switch circuit. With the with made of fabric and aluminium foil either the right or the left LED can be chosen.
Mm30.png Mm50.png Mm40.png
This circuit exploits the fact that the coin cell battery can be inserted in two ways and that the LED is a diode. Depending on the orientation of the battery either the blue or the red LED will light up. schema of the two led-diodes. It is the basics for Charlie Plexing circuits, where there are more LED's connected to a microcontroller than free legs available. This effect can be used for story telling, as is shown in this swatch. The men either fight with their fists or kick with their feet.


Sm40.png

Testing the simple circuit

Sm38.png

Testing the parallel circuit.

Sm51.pngSm52.png

A Fabric Switch


results - The Soft speaker

A soft speaker can be built, by using conductive wire and a magnet, in combination with a 555 timer circuit with LDR, with a 9V battery.

The sound is really soft! The tone is varying according to the light on the LDR.

The schema of the circuit: https://cdn.makezine.com/uploads/2014/08/555ss_bboard_4-3-ratio_annotation.png

Sf1.png

The circuit on the breadboard.

See also: https://www.kobakant.at/DIY/?p=3652

Failure

So I made three versions of the soft speaker on one swatch. That made things rather complex. Connecting the one 555 timer circuit conveniently and comprehensibly to the three speakers for testing is already a problem.

Sf20.png

Three versions of a soft speaker. To the left: copper wire, sewn on the fabric, in the middle, spiral of copper sheet cut with a lino cutter. To the right the conductive metal wire, embroidered on the fabric. The problem with this is that the metal "sticks" to the magnets.

So I decided this was a failure, and made a new one with only one: the enameled copper wire. This is now much simpler and shows the principle. The only problem remaining is how to sew the copper wire to the fabric. I tried several ways. This swatch is not really the most beautiful solution.

Sf21.png Two together.

Sf23.png Final version, the sewing is still a mess.

results - 7 LED's in Folding

(still some details, like embroidering the title on the swatch, have to be done)

Using the folds of fabric to hide the LED's and to get the light of the LED's reflected from the surface.

Microcontroller: ATTiny85, with 5 I/O pins, and 7 LED's so using Charlieplexing. This circuit runs at 3V.

The ATtiny85 can be programmed simple within the Arduino environment, using the ATtiny plugins.

The code can be found here: https://github.com/contrechoc/charlieplexed-swatch

Sf3.png front

Sf4.png back


Illuminated Lace

Using 8 LED's on 4 PIN's of the ATtiny85 as a backlight for a lace.

With a fabric battery holder and a switch inside fabric.

Cp0.png without the lace covering

Cp1.png

Cp2.png

The script can be found here: ....somewhere!


Joule Thief

The Joule thief uses a boost circuit for making 3V from a 1.5V battery.

The battery holder is using aluminium foil on fabric to do two things: it serves as a battery holder and it serves as the switch. The LED starts when the conductive pieces are pushed against the plus and minus of the battery.

The schema for a Joule Thief can be found on many places, for instance: https://diyteach.wordpress.com

The most tricky step is the winding and connecting the wires around the ferro toroid: here you find a clear image: https://www.instructables.com/id/Itty-Bitty-Joule-Thief/

Jt99.png

more info can be found here: http://interactionstation.wdka.hro.nl/wiki/Energy_for_Designers#Week_1_-_Day_2

results - fabric and TFT screen

Examples/intro

For more advanced applications electronic components have to be sewn into the fabric.

Different small screens are available, like LCD (one color) and TFT (color).

Sr9.png LCD screen, only some text and numbers. It can be used for data, like the temperature "at that moment". This means you cannot show the change in temperature during a longer time in a graph.

For displaying data, graphs (say the temperature during a day) and pictures a small TFT screen can be used. The TFT screen has "pixels" line 160 x 128, and fonts, and an sd-card to store images.

Sr20.png Some examples, the data are clear, the left: the three circles are representing R - G - B data of the incoming light. The circles are always touching, the radius is the number, this is a small algorithm. The middle is "art" the data are noised by the colored squares, the resulting image is a bit more than boring numbers, the right is a bar chart.

Sr21.png Some examples, a graph can be seen, changing in time, boring numbers and a representation of a sensor array at the right.

You could fit the screen on the fabric without any support - just sew it with threads.

Sr11.png Sr10.png

An application:

Sr7.png Project Laboratoire Aeroporté, 2019, Paillard, Poncé-sur-le-Loir

Sr8.png Project Laboratoire Aeroporté, 2019, Paillard, Poncé-sur-le-Loir



Making a Fabric window

For other applications the components have to find a place inside the fabric and have to be supported by the fabric.

Sr1.png

This simple way to cut a rectangle in for example paper is not giving a nice result in fabrics.

Sr2.png

Another way to construct a window must be developed. Other solutions are possible, depending on your virtuosity with fabrics.

Sr3.png

Also the electronics becomes more complex, with many wires. Here "normal" electrical wires are used, not the conductive thread. With too many wires, and batteries and many components the wires have to be isolated.

Sr4.png

Some pictures of the result.

Sr5.png

Pictures can be shown, or graphical representations, like graphs with data.

Sr6.png

Remarks: I used here "another" and cheaper TFT screen. Normally with the libraries of Adafruit these screens will be running in no time. Of course around 10 wires must be soldered between the TFT screen and the microcontroller. But this other screen had some other properties. So it took me a few hours to figure out what was "different" or which wires were sewn wrongly. In the end it turned out to be the backlight of the screen which must be used, an extra LED connection. Also it can be seen in the pictures that the SD card is the bigger size, while the Adafruit TFT already uses the micro sd-card. So it can be that I saved a few euro's but then you have to be prepared for other characteristics or "retro" parts...

In all making this part of a swatch took me way longer than expected, the searching for the right way to use the TFT screen, and the development of the fabric window. Then the connection to the Lipo battery, with a switch, the programming and finding and making your own pictures, besides making graphs if data are displayed. The problem is also that your brains have to switch between many specifications, like sewing, electronics, programming, how to display data etc. This makes it practically impossible to do all in one day.

Variable Resistance Knitting

A knitted tube from conductive thread or a combination of yarn and conductive thread can make a variable resistor. Depending on the ind of conductive thread the total resistance will vary when the tube is pulled out. The exact mechanism is the "touching" of the thread over the knitted loops. When pulled, the loops will be connecting more tightly, making the resistance lower.

Some values:

  • smooth metal wire tube: from 2 Ohm to 1 Ohm (so not too much variability)
  • Conductive wool: from 48 kOhm to 100 Ohm
  • Conductive metal thread with sticky metal conductive thread 50 Ohm - 4 Ohm.

Kt2.png Knitting a tube with red yarn and grey metal conductive thread

Kt1.png The three different tubes, top: smooth metal conductive, middle: sticky metal conductive with red yarn, bottom: conductive wool thread

Rk4.png More tubes, with different yarn combinations, and the values.

See more details here: http://interactionstation.wdka.hro.nl/wiki/ResistanceKnitting

The swatch will contain an ATtiny85 with two led's. The second one will light up if the knitting is pulled. Depending on the resistance of the tube, there must be a second fixed resistor in the circuit, which has a middle value. The the analog PIN can be read and the microcontroller can see if the knitted tube is pulled.

Pull sensor from knitted conductive wool

Using an ATtiny85 with a voltage divider.

The conductive wool, knitted into a tube has a nice range of resistance when pulled: relaxed, 500K Ohm, pulled 50 Ohm.

With a resistor of 2K Ohm, and the appropriate scripting, this is a reliable pull sensor.

Script: https://github.com/contrechoc/swatches/blob/master/knitted_pull_sensor

Application: breathing sensor, in a band around the chest. Bending sensor for the arm, situated on the elbow.

Ps1.png

SoftPotMembrane

An example of adding electronic components to fabric. The only "soft" part is the membrane but even this is relatively "hard".

Microcontroller: ATtiny85 - 8Mhz, + speaker 3V coin cell battery

SoftPot Membrane Potentiometer - 50mm

https://www.floris.cc/shop/en/flex-force/740-softpot-membrane-potentiometer-50mm.html

Datasheet membrane: https://www.sparkfun.com/datasheets/Sensors/Flex/SoftPot-Datasheet.pdf

The pitch of the tone from the speaker can be altered by touching the strip at several places. It also works as a capacitive sensor.

Script: https://github.com/contrechoc/swatches/blob/master/softpot_membrane

Rr4.png

intermediate result, without an embroidered title.

Woven battery holder - ATtiny connected pithing the woven structure

Made on a so called baby loom, see last image if this section.

A simple circuit with an ATtiny85, and two LED's. You have to fold the side so that it forms a battery holder. The LED's will blink and if you come close to the ATtiny with your finger the blinking frequency will change - capacitive effect.

You have to press the battery on to the yarn.

The polarity - plus and minus are indicated on the swatch. Don't put the battery in the wrong way: the ATtiny85 will die!

Wb3.png Wb1.png

https://www.flickr.com/photos/contrechoc/albums/72157713148275338

https://github.com/contrechoc/swatches/blob/master/woven_batteryholder

Weaving this swatch is time consuming! Although this is fun making, I don't think this will become very popular :-)

If you start making this: program the ATtiny85 first, before soldering the conductive wire to the legs....

You need solderable conductive wire for this: The Karl Grimm, which you cannot buy anywhere unless you are an industrial consumer!

Wb4.png Another example of weaving and connecting to an ATtiny85 - which I made during the e-textile summer camp in ... 2015(?)

Sensor swatches

ATtiny85 + LDR light sensor.

Rr1.png

ATtiny85 + Force Sensitive sensor: https://www.floris.cc/shop/en/flex-force/738-force-sensitive-resistor.html

Rr2.png

ATtiny85 + NTC Temperature Sensor: http://interactionstation.wdka.hro.nl/wiki/Thermistor

Rr3.png

These swatches show in a simple way the working of these basic sensors.

In principle these resistors are voltage dividers, where the sensor is a variable resistance.

The data are thus "relative" to the values of the resistors, the data are not "real", not calibrated by the sensor. The data can be calibrated by the code, like the NTC.

Microcontroller ATtiny85

https://cdn.sparkfun.com/assets/2/8/b/a/a/Tiny_QuickRef_v2_2.pdf

I am using this cheap microcontroller for many smaller projects. It is very cheap compared to the Arduino, but of course, just a few PINs and just a bit of memory.

Tutorial: https://learn.sparkfun.com/tutorials/tiny-avr-programmer-hookup-guide/attiny85-use-hints

You need a chip holder, unless you want to solder directly to the pins.

Mc1.png Mc2.png Mc3.pngPin view, chip holder, ATtiny85

The ATtiny is programmable inside the Arduino environment. But if you need all the memory, you can better program it in AVR.

Flashing the program is done with a programmer, the most convenient for the ATtiny85 (I think) is: Tiny AVR programmer - https://www.floris.cc/shop/en/home/996-tiny-avr-programmer.html

Mc4.png Comparing the sizes of Arduino, the Arduino Pro mini, and the ATtiny85

Adafruit has boards with ATtiny, then it is easier to program and attach to the PIN's: Adafruit Trinket - for us in Europe, buy at a local webshop...

Slow and fast sensors

This swatch has a TFT screen, not sheltered in fabric.

Fast acceleration Sensor: ADXL345: https://learn.sparkfun.com/tutorials/adxl345-hookup-guide?_ga=2.89251487.561194753.1589359662-1975814699.1588796476 Slow environmental Sensor: BME680: https://learn.adafruit.com/adafruit-bme680-humidity-temperature-barometic-pressure-voc-gas/

The code: https://github.com/contrechoc/swatches/blob/master/fast_slow_sensor_swatch

The slow data are displayed as numbers, the fast data, acceleration as graphs in time.

The sensors are providing "real" data in physical units, temperature in degrees, pressure in bar, etcetera.

These two sensors are connected using the I2C protocol.

Sparkfun and Adafruit are also providing the libraries and example code.

The sensors are connected to a Arduino Pro Mini 3V (Be careful: the 5V connection is deferred to the RAW Voltage input on the microcontroller. Then this voltage is regulated to 3.3V.

References

A movie of "the" e-textile swatch book 2013: https://www.youtube.com/watch?v=YcmxE24VdWA

Documentation of the e-textile swatch exchange books:

http://etextile-summercamp.org/swatch-exchange/category/2017/

http://etextile-summercamp.org/swatch-exchange/category/2016/

http://etextile-summercamp.org/swatch-exchange/category/2015/

http://etextile-summercamp.org/swatch-exchange/category/2014/

http://etextile-summercamp.org/swatch-exchange/category/2013/


Mika and Hannah: https://www.kobakant.at/DIY/

Many techniques and workshops are documented here:

http://etextile-summercamp.org/2016/

http://etextile-summercamp.org/2015/

http://etextile-summercamp.org/2014/

http://etextile-summercamp.org/2013/