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TUTORIALS

STRAWBERRY FIELD

Instructions

STEP 1: Pompoms fabrication

  1. Start from printing 9 pompoms holders3. TPU filament were used for printing as it is easier to push through the pompom and will make sewing easier.

  2. The wrapping of the thread is made from a 3 mm thick and 15 mm wide piece of felt. 250 wraps of thread for 300 Ω/m Shieldex® Wrapped Yarn-dyed red conductive thread. One pompom is made from 2.5 kΩ/m Shieldex® 235/36 conductive thread.

  3. The end of the pompom is knotted with thread, leaving two ends of 15 cm each for sewing the circuit later.

  1. The other end of the wrap can be cut with scissors. The knot can be tied again to secure the pompom threads.

  2. 2 threads should be inserted through the top of the holder, i.e. the narrower part of the hole.

  3. By pulling the threads together, the pompom should slide into the hole of the holder and secure into place.

  4. The same process can be repeated with other pompoms.

STEP 2: Circuit

  1. This electrical circuit vector file2 allows to use sublimation print technique on fabric. Open the file in Inkscape and you will see the layers named: snaps - marking for the frame snap-fasteners , frame - to cut the frame from 3 mm felt, circuit - for what can be printed and as guide for the circuit embroidering.

  2. ATtiny PCB tutorial and fabrication files56 at the bottom of the page.

STEP 3: Code

For the code4 Charlieplexing technique were used following Plusea sample book.

STEP 4: Power

For this swatch 9V battery were used. Snap-fasteners connections[7] with battery materials list bellow:

materials
  • double side conductive fabric tape 50 mm
  • 9.5 mm metal snap-fasteners
  • 40 Ω/m Shieldex® 235/36 HCB conductive thread
  • regular thread
  • 3 mm felt
  • 1.5 mm felt
  • 9V Battery Snap Connector

FABRICATION MATERIALS | Strawberry field

MATERIAL PRICE LINK
40 Ω/m Shieldex® 235/36 HCB conductive thread 4.95 €/sample cone Shieldex
300 Ω/m Shieldex® Wrapped Yarn-dyed red conductive thread 4.95 €/sample cone Shieldex
2.5 kΩ/m Shieldex® 235/36 conductive thread 4.95 €/sample cone Shieldex
double side conductive fabric tape 50 mm 8.72 €/20M Aliexpress
9.5 mm metal snap-fasteners 4 €/60 pcs. Kaivida
10 mm metal snap-fasteners 5.85 €/60 pcs. Kaivida
TPU filament FiberFlex 40D 1.75mm 40 € Anodas
Fiberglass fabric impregnated with PTFE 0.13 mm 21.18 €/1M e-plastena
1.5 mm polyester felt 9.60 €/1M Danesa
3 mm polyester felt 10.43 €/1M Danesa
Griffin® braided nylon cord 2mm 3.98 €/25M Veriame

ELECTRONICS | Strawberry field

QTY COMPONENT PRICE LINK
1 ATTINY85-20PU 1.54 €/1 pc. Farnell
1 8 contacts DIP Socket 0.11 €/1 pc. Farnell
2 470 KΩ through hole resistor 0.04 €/1 pc. Farnell
6 LilyPad Led white 1.32 €/20 pc. Aliexpress
1 9V Battery Snap Connector 0.47 € Farnell
1 9V Battery 1.67 € amazon

ATtiny flex PCB

All of the materials listed below are easily plated, although a laser cutter will not cut copper tape. PCBs consist of three layers: bottom - fiberglass fabric, middle - copper tape and top might be fiberglass fabric or kapton tape.

Instructions

STEP 1:

  1. cut the layers using the materials as shown in the picture bellow. The same drawings are in fabrication file56.

  1. Unnecessary parts of the copper tape can be carefully peeled off using tweezers.

  2. Transfer film is applied to the cleaned part.

STEP 2: layer the materials.

  1. Attach the copper tape part on the fiberglass fabric bottom part using transfer film.

  2. Bend 8 contacts DIP Socket legs sideways and press down on a flat surface.

  3. Solder DIP Socket to copper part, use the weight and some flux to make this work easier.

  4. The upper part should be placed on the socket, drops of super glue helps to secure this part. Insulating tape attached with the adhesive side facing up will help precision when gluing parts.

FABRICATION MATERIALS | ATtiny flex PCB

MATERIAL PRICE LINK
double side copper tape 50 mm 4.57 €/10M Aliexpress
Fiberglass fabric impregnated with PTFE 0.13 mm 21.18 €/1M e-plastena
8 contacts DIP Socket 0.11 €/1 pc. Farnell

References

Capacitive swipe example >> https://www.kobakant.at/DIY/?p=4855

Charlieplexing >> http://en.wikipedia.org/wiki/Charlieplexing

FABRICATION FILES

  1. strawberry field circuit PDF ↩

  2. strawberry field circuit SVG ↩

  3. pompom holder STL ↩

  4. strawberry field code TXT ↩

  5. ATtiny PCB SVG ↩↩

  6. ATtiny PCB PDF ↩↩

  7. Connections files for laser cutting ↩

Last update: 2023-05-12