Hacked knitting machine — generated patterns

Path	Target	Duration	Skills
Discovery	18-25	1 day	Digital Design, generative patterns, spreadsheet, machine knitting

Objectives¶

This workshop aims at introducing beginners to code by using a tangible medium. Using the gender bias of textile to counter balance the gender bias of new technologies.

Learning Outcomes:
Understand how IT can help the design process
Produce an [object/prop/pattern] using a spreadsheet to grasp some coding aspects.
Learn to use a hacked knitting machine

Target audience and contexts of use

Students with an interest in textiles, art school teachers. If participants don't have basic knowledge of machine knitting, casting the stitches on the machine will be made by the facilitators.

To teach this use, one computer per person is required as well as at least one hacked knitting machine.

Recommended number of participants: 6–8

Preparation and materials¶

Equipment, tools and materials

Equipment

hacked knitting machine
Computers with LibreOffice installed
Sufficiently spacious tables and chairs
A screen or projector for the demonstration

Material

yarn of at least 2 different colors

Introduction and context¶

We are using a spreadsheet editor to generate patterns from a sequence of numbers. Odd and even numbers are visualized by black and white pixels/cells. Then a python script is used to transform those numbers into a bitmap image that we can transfer to the knitting machine with the Ayab software.

One column of the spreadsheet represents one needle of the knitting machine.
One row of the spreadsheet represents one knitting row (so one pass of the carriage).

Tutorial¶

!!! Advice: do not forget to save your file regularly as an .odt file !!!

Preparing the spreadsheet to visualize odd/even numbers with colors

step 1: Install Libre Office

Install LibreOffice, a gratis free/open source spreadsheet software → https://libreoffice.org/

step 2: Grid setup

Create a new Calc document.
Select all cells by clicking Ctrl+A.
Right-click on the column names (A, B, C…) → Click on "Column width" → Type "5mm".
Right-click on the row names (1, 2, 3…) → Click on "Column height" → Type "5mm".

step 3: Conditional formatting

This step will render white cells for even numbers, black cells for odd numbers.
Click on "Format/Conditional/Manage"
Click on "Add"
In order to check whether a number is even: in "Condition 1", select "Formula" and type next to it: MOD(A1,2).
Please note that on some versions of LibreOffice, you might need to replace the comma sign (,) by a semi-colon sign (;). So MOD(A1,2) would become MOD(A1;2).
In the dropdown menu "Apply a style", choose "New style" → Select a black background color → Validate.

↑↑↑ Screenshot of conditional formatting window. ↑↑↑

1.A Draw a pattern by hand¶

Draw by typing in numbers by hand

step 1: Prepare the canvas

Type a 0 in the first cell A1.
Select cell A1.
Copy the cell A1 by clicking on Ctrl+C.
Select all the cells needed to cover the desired working area.
Click on "Edit/Paste Special/Paste Transposed".
All selected cells should be filled with zeroes. This is important as if there are no numbers in the white cells, the conversion script that we will use later won't work.

step 2: Draw

Select the cell you want to paint black.
Type a 1 in it. The cell should turn black.
Repeat "Step 2" to paint all desired cells in black.

step 3: Erase

If you want to transform a black cell into a white cell, type a 0 in the cell.

step 4: Extend your pattern

Once you've made your pattern
Select the cells of your pattern
Drag&drop the bottom-right corner to the right to extend your pattern to the right, or below to extend your pattern to the bottom.

: Step 4

1.B Generate a pattern with formulas¶

Pattern Generation

step 1: Variables

Create a new sheet at the bottom and call it "Variables".
In the first column, fill some cells with some numbers of your choice.
Select the filled cells and drag&drop the bottom-right corner of the selection down to row 50 (or whatever number of rows you want to knit).
The software attempts to guess some logics to the number sequence you input.
Note: On this sheet, the cells stay white. It's normal as the conditional formatting is only applied on the first sheet. Otherwise, we would have to repeat those steps for this sheet…

step 2: Connecting sheets

Go back to the first sheet.
Select cell A1.
Type in this cell: =$Variables.$A1
Make sure that the spelling and lettercase match the name of your second sheet "Variables".
Drag&drop the bottom-right corner of cell A1 down to row 50. The cells will fill with the same numbers as on the "Variables" sheet.

step 3: Formulas

In cell B1, write a mathematical formula using a cell from the previous column. Always use the FLOOR() function to round the numbers, otherwise the conditional formatting might not work. Here is a formula example: =FLOOR(A1/4)
Drag&drop cell B1 down to row 50.

step 4: More formulas

In cell C1, write a mathematical formula using cells from the two previous columns. Again, don't forget the FLOOR() function to round numbers. Here is a formula example: =FLOOR(A1-B1)
Drag&drop cell C1 down to row 50.

step 5: Extend pattern

Select columns A, B and C. Drag&drop the bottom-right corner to the right until column AZ (or the desired column for the total pattern. 1 column represents one needle/stitch on the knitting machine).
You now have a pattern!

step 6: Adjust the pattern

Because we used variables, we can edit the pattern by editing numbers in the "Variables" sheet. The pattern on "Sheet 1" will update automatically.
If you want to add more formula columns before step 5, you can!

: Step 2

: Step 3

: Step 4

: Step 5

2. Prepare the pattern for the knitting machine¶

Exporting the pattern

Export to .csv

Click on "File/Save As".
Choose the .csv file type.
Transfer the file to the facilitator.

We need to convert our .csv file to an image file such as .png or .jpg. During the workshop, to make things easier, the facilitator will convert the .csv files to .png files. Here are the steps for the facilitator (or any participant willing to go deeper in the process).

Convert .csv file to .png

step 1: Preparation

Download the Python script Python csv2xpm.py here: https://gitlab.com/svilayphiou/csv2xpm/-/raw/main/csv2xpm.py?inline=false
Get the .csv file from participant and save it in the same folder as the file csv2xpm.py.
Open a Terminal.

step 2: Run the script

Go into the folder where the file csv2xpm.py is located. For this, type cd /path/to/csv2xpm.py (replace the path according to where your file is located), and validate by typing the Enter key.
Type python csv2xpm.py my_pattern.csv (replace the .csv filename accordingly) and validate by typing the Enter key.
If you look in a file browser, a file called my_pattern.xpm (according to your .csv filename) has appeared.

step 3: Convert .xpm to .png

Open the my_pattern.xpm file with a bitmap editor such as (Gimp)[https://www.gimp.org/].
Export the image with a .png extension → my_pattern.png.

Troubleshooting the script¶

Sometimes the script does not work right away… (sorry for that!) In that case, open the .xpm file that is not working with a code or text editor.

The .xpm file will look like that:

! XPM2
8 25 2 1
A c #000000
V c #ffffff
AVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAA
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
AVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAA
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
AVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAA
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
AVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAAVAA

On line 2, the first number 8 corresponds to the number of rows of the picture, so the number of lines of the file starting from line 5.

The second number 25 corresponds to the number of columns of the picture, so the number of characters each line (starting from line 5) has.

If those numbers don't match, you would have to replace the numbers with the correct ones. A code editor should tell you easily the line and columns numbers so you don't have to count all the lines yourself!

Once you're done correcting, you can save the file on itself and start again at "step 3".

3. Knitting the pattern¶

Knitting preparation

Cast on

Cast on the number of stitches according to your pattern centered on the machine.
Knit a few rows with the background color.

To send the pattern to the knitting machine, you need tha Ayab software available here: https://ayab-knitting.com/.

Ayab 0.95 quick manual

Preparation

Click on "Load file" to upload your my_pattern.png image file.
Plug the Arduino to your computer with a USB cable.
Choose the port where the Arduino is connected (in general, there is only one choice. On Linux, it is usually /dev/ttyUSB0 or /dev/ttyACM3).

Configure

Knitting mode: Single Bed
Colors: 2
Start Row: 1
Start Needle: 26
Stop Needle: 26
Alignment: center
Click on Configure.

Init

Plug your knitting machine to an electric socket.
Turn on your knitting machine (you should see a red line on the power on switch).
Click on "Knit!".
Put the carriage on the left side going over the left arrow mark of your machine.
Put the carriage on mode KC II.
Push the carriage on the right just after the left arrow mark. The Ayab shield should beep three times.
Pass the carriage over your knit to the right.

Jacquard

Press the MC button.
Put the second color in the B slot of your carriage.
Knit across. The shield should beep at the end of the row.
Knit as many rows as needed. At the end of the pattern, the shield will beep dramatically.

Photos¶

Photos of the workshop

Last update: September 30, 2022