Knitting with the Knit Editor – First Success

With AYAB we are working on an editor which also has the ability to control a knitting machine. Here is the progress we made: one can control the needles and get some instructions on what to do:

Views of the Editor

The editor has several view. To begin with, you can either load or save patterns as knitting patterns or images:


This is the incomplete editor view, where you are able to add and remove instructions and rows and build your knit work:


Once, your pattern is done, you go over to the knit settings. Currently, there is only one ability to knit, knitting with the AYAB hack. You can choose your machine type and the connection and start knitting.


After you started knitting, you see the pattern which you want to knit.


Right next to the pattern, you can see the instructions for you. You can follow these to create the knit peace.


You can also open the settings menu by pressing F1. There you can choose your language:


At the current state, all this is rather sketchy. The basics work. For the best user experience, there is still a lot to do.


I started a conversation on and was inspired to take a closer look at DesignaKnit 8.

A free Demo version of DesignaKnit is available which cannot save changes to patterns or shapes and cannot connect to a knitting machine. Otherwise all functionality is available.

DesignaKnit contains:

  • an editor for color patterns
  • an editor for shapes or sewing patterns
  • a shape library
  • a tool for converting images to patterns
  • interactive knitting

Patterns can be applied to shapes.

I did not look very closely at the editors because I do not know much about pattern generation, especially shape or sewing patterns. And the editor for the color patterns did not work for me.

Interactive Knitting:
I took a look at some of the features available in the interactive knitting. There are some interesting features we would also like to implement.

I was not able to take in all the functions available. I could not connect it to a machine and I am still a beginner with knitting machines, which is why I am probably missing some features which make life easier.

The interactive knitting support has several views:

  • overview of knit piece which also shows the position of the carriage
  • view for next row to be knit, some rows around for context
  • view for yarn colors in use and visualization that shows which yarn is currently in the carriage and being knit
  • view for instructions to the human, which also contains
    • row counter as it should be on the machine
    • counter for row in the piece being knit
    • counter for row in pattern
    • information on start and stop needle on machine


DesignaKnit can be configured to play sounds when an action, like decreasing the number of meshes, needs to be taken. Voice cuing is also possible. Furthermore, the view for the instructions for the human can flash yellow and displays what step needs to be completed by the human next. In the image above the number of meshes should be decreased by 6 on the right side.

Ideas for our interactive knitting support:
The idea of extra audio and visual cuing is very interesting and we are considering also having this option in our interface. We are not yet sure how we will organize all the information, but the information we will show to the user will be similar to what is shown in DesignaKnit.

The interface for DesignaKnit serves its purpose well. However, we think we can create something that is a little more appealing to the eye.
To keep our Design of the user interface clean and simple we are designing for mobile devices first.


Code Quality in the knittingpattern Python Library

In our Google Summer of Code project a part of our work is to bring knitting to the digital age. We is Kirstin Heidler and Nicco Kunzmann. Our knittingpattern library aims at being the exchange and conversion format between different types of knit work representations: hand knitting instructions, machine commands for different machines and SVG schemata.

Cafe instructions
The generated schema from the knittingpattern library.
The original pattern schema Cafe.








The image above was generated by this Python code:

import knittingpattern, webbrowser
example = knittingpattern.load_from().example("Cafe.json")".svg"))

So far about the context. Now about the Quality tools we use:


Continuous integration

We use Travis CI [FOSSASIA] to upload packages of a specific git tag  automatically. The Travis build runs under Python 3.3 to 3.5. It first builds the package and then installs it with its dependencies. To upload tags automatically, one can configure Travis, preferably with the command line interface, to save username and password for the Python Package Index (Pypi).[TravisDocs] Our process of releasing a new version is the following:

  1. Increase the version in the knitting pattern library and create a new pull request for it.
  2. Merge the pull request after the tests passed.
  3. Pull and create a new release with a git tag using tag_and_deploy

Travis then builds the new tag and uploads it to Pypi.

With this we have a basic quality assurance. Pull-requests need to run all tests before they can be merge. Travis can be configured to automatically reject a request with errors.

Documentation Driven Development

As mentioned in a blog post, documentation-driven development was something worth to check out. In our case that means writing the documentation first, then the tests and then the code.

Writing the documentation first means thinking in the space of the mental model you have for the code. It defines the interfaces you would be happy to use. A lot of edge cases can be thought of at this point.

When writing the tests, they are often split up and do not represent the flow of thought any more that you had when thinking about your wishes. Tests can be seen as the glue between the code and the documentation. As it is with writing code to pass the tests, in the conversation between the tests and the documentation I find out some things I have forgotten.

When writing the code in a test-driven way, another conversation starts. I call implementing the tests conversation because the tests talk to the code that it should be different and the code tells the tests their inconsistencies like misspellings and bloated interfaces.

With writing documentation first, we have the chance to have two conversations about our code, in spoken language and in code. I like it when the code hears my wishes, so I prefer to talk a bit more.

Testing the Documentation

Our documentation is hosted on Read the Docs. It should have these properties:

  1. Every module is documented.
  2. Everything that is public is documented.
  3. The documentation is syntactically correct.

These are qualities that can be tested, so they are tested. The code can not be deployed if it does not meet these standards. We use Sphinx for building the docs. That makes it possible to tests these properties in this way:

  1. For every module there exists a .rst file which automatically documents the module with autodoc.
  2. A Sphinx build outputs a list of objects that should be covered by documentation but are not.
  3. Sphinx outputs warnings throughout the build.

testing out documentation allows us to have it in higher quality. Many more tests could be imagined, but the basic ones already help.

Code Coverage

It is possible to test your code coverage and see how well we do using It gives us the files we need to work on when we want to improve the quality of the package.


Landscape is also free for open source projects. It can give hints about where to improve next. Also it is possible to fail pull requests if the quality decreases. It shows code duplication and can run pylint. Currently, most of the style problems arise from undocumented tests.


When starting with the more strict quality assurance, the question arose if that would only slow us down. Now, we have learned to write properly styled pep8 code and begin to automatically do what pylint demands. High test-coverage allows us to change the underlying functionality without changing the interface and without fear we may break something irrecoverably. I feel like having a burden taken from me with all those free tools for open-source software that spare my time to set quality assurance up.

Future Work

In the future we like to also create a user interface. It is hard, sometimes, to test these. So, we plan not to put it into the package but build it on the package.

Knitting Pattern Conversion


We can convert knitting patterns to svg (middle) which proves the concept but is still a different from the original (right)

Our goal is to create a knit-work exchange format. This includes the conversion to a scematic view of the knittting pattern as svg – to make it endlessly scalable and allow conversions to png, pdf and paper.

This week we ended the prototype of the SVG conversion. The positions are a bit off and instructions are placed above eachother. Most of the work is done.

We are also able to load and save knitting patterns a png files.

(1)a34e6d2c-372d-11e6-9bbd-71c846ead7f9 (2)f6a6bf82-372e-11e6-9467-8bab0e07c099


We loaded them (1), converted them to a knitting pattern and then saved them again as png (2). This way we path our way towards using the ayab software and actually knitting the pattern. Also we can convert the knitting pattern to an svg consisting all of knit instructions (3). Here is the code for it in version 0.0.8.

>>> import knittingpattern
>>> from knittingpattern.convert.image_to_knittingpattern import *
>>> convert_image_to_knitting_pattern.path("head-band.png").temporary_path(".json")
>>> k = knittingpattern.load_from_path("head-band.json")
>>> k.to_svg(10).temporary_path(".svg")

Here you can see a proof of concept video:


A look into the knitting pattern format

We are currently working on a format that allows to exchange instructions for knitting independent of how it is going to be knit: by a machine like Brother, Pfaff, or by hand.

For this to be possible we need the format to be as general as possible and have no ties to a specific form of knitting. At some point the transition to a format specifically designed for a certain machine is necessary. However, we believe that it is possible to have a format so general that instructions for all types of machines and for hand knitting could be generated from it.

We have decided to use JSON as the language to describe the format, because it is machine readable and human readable at the same time.
The structure of our format follows the rows in knitting.

Our first thought was about creating a format that would describe how meshes are connected and how the thread travels. This would allow for great flexibility and it should be possible to represent everything like this. However, we have decided against it, because we think this format would be quite complicated (different orientations and twists of meshes possible, different threads for multiple colors…) and would get quite big very quickly, because of all the different properties for each mesh and because of all the meshes. Furthermore, and this point is probably more important, knitters do not think this way. If we had a format like that, it would not be easy to understand what was happening for human beings.

Whenever I knit by hand, I never think about how all the meshes are connected by this single thread I am using. I always think about which operations I am performing when knitting in each row. Instructions for creating patterns in knitting are also written this way. They give the knitter a set of knitting instructions to do and possibly repeat. We have concluded, that most knitters think in knitting operations performed rather than connections between meshes.


Knitting instructions from Garnstudio’s Café.

Therefore we have decided to base our format on knitting instructions/operations. The most common instructions probably are: knit, purl, cast on, bind off, knit two together, yarn over. Of course for increases and decreases there are many different operations which work in a similar way but have slight differences (e.g. skp, k2tog).
Since in knitting many things are possible and it is unlikely that we ever manage to create a complete list of all the possible operations you can perform in knitting we have decided to have a very open format, that allows the definition of new instructions.

Instructions are also defined in JSON format. Here is an example, the “k2tog” instruction:

        "type" : "k2tog",
        "title" : {
            "en-en" : "Knit 2 Together"
        "number of consumed meshes" : 2,
        "description" : {
            "wikipedia" : {
                "en-en" : ""
            "text" : {
                "en-en" : "Knit two stitches together, as if they were one stitch."


Knitting patterns consist of multiple rows, which consist of multiple instructions. Furthermore we want to define the connections between rows. This is important, so we can express gaps or slits which are multiple rows long. For example when knitting pants the two legs will be separate. They will be knit separately and their combined width will be increased in comparison to the width of the hip.
Here is an example for a pattern which specifies a cast on in the first row, then a row where all stitches are knit, then the last row is bound off.

  "type" : "knitting pattern",
  "version" : "0.1",
  "comment" : {
    "content" : "cast on and bind off",
    "type" : "markdown"
  "patterns" : [
      "id" : "knit",
      "name" : "cobo",
      "rows" : [
          "id" : 1,
          "instructions" : [
            {"id": "1.0", "type": "co"},
            {"id": "1.1", "type": "co"},
            {"id": "1.2", "type": "co"},
            {"id": "1.3", "type": "co"}
          "id" : 2,
          "instructions" : [
            {"id": "2.0"},
            {"id": "2.1"},
            {"id": "2.2"},
            {"id": "2.3"}
          "id" : 3,
          "instructions" : [
            {"id": "3.0", "type": "bo"},
            {"id": "3.1", "type": "bo"},
            {"id": "3.2", "type": "bo"},
            {"id": "3.3", "type": "bo"}
      "connections" : [
          "from" : {
            "id" : 1
          "to" : {
            "id" : 2
          "from" : {
            "id" : 2
          "to" : {
            "id" : 3

Connections are defined “from” one row “to” another.  The ids identify the rows. The optional attribute start defines the mesh where the connection starts. If start is not defined, the first mesh of the row is assumed. When indexing the list of meshes in a row the first index is 1. The optional attribute “meshes” describes how many meshes will be connected, starting from the mesh defined in “start”.

The resulting parsed Python object structure looks like this:

row model

The Python object structure for working with the parsed knitting pattern.

Each row has a list of instructions. Each instruction produces a number of meshes and consumes a number of meshes. These meshes are also the meshes that are consumed/produced by the rows.


Towards a unified digital aproach to knitting

Our idea is to create a knitting library for a format that allows conversion of knitting projects, patterns and tutorials. Usually, communities will only focus on the knitting format for their machines. Our approach should be different and be able to support any knitting communities efforts.

Here is our strategy to achieve this:

  • We connect to different communities to get a broader view on what their needs are.
  • Our knitting format is based on knitting instructions like knit, purl, yarn over, skp. We found a comprehensive list on Wikipedia.

Other Communities

From time to time we meet with other people who also knit and could use our software.

First, we met with Viktoria from ETIB Berlin. She taught us a lot about knitting, how she does it, that almost everything could be created from one peace with the machine. Also, that AYAB is used for lace patterns. We saw examples where she let meshes fall so that larger holes were created. Our goal is to support laces in the file format.  Color patterns should be possible across sewing edges.

We are also in touch with Valentina Project. With their software we would be able to connect to yet another community and use their sewing patterns for custom-fit clothes.

We got in touch with Kniterate. They and we share a lot of goals. Because they create a startup, they are very cautious what they release. They focus on their open-source knitting machine first and later on the software. They already created an editor much like we imagined ours to be, but as a web application. A way of collaboration could be that we understand their file format and see how we can support it.

Only talking about our GSoC project is worth it as other people may have seen alike at Maker Faires and other hacky places. We have the chance to bring communities and efforts together.

Knitting Format

A universal knitting format has many concerns:

  • Languages of users differ
  • It should be possible to knit by hand
  • Mesh sizes and wool differ
  • Different knitting machines with different abilities
  • A knitting format for exchange is never complete. A knitting format for machines must be complete.

In contrast to a knitting format for a automatic machine, it is possible, to have machines operate in semi-automatic modes or just to knit by hand. In both cases, meshes could be changed in a way that was never foreseen. This is why we did not base it on meshes and mesh types but rather on instructions – closer to the mental model of the knitters who perform instructions with their hand.

Some of the instructions are understood by the machines, some could be adapted a bit so the machine can do it automatically or faster and some are still necessary to be done by hand. We created a Python module for that, “knittingpattern“. We work on it in a test-driven way.


Functionality of KnitWeb Application

Hi Everyone,

In this blog post I will show what are the functionalities implemented in KnitWeb application. First of all let us look into why there is a web application to get a knitting job done. It’s simple. Going for a web application is the best way to acheive platform independence among all the knit app firmware. So the if the hardware level functionality can be abstracted out to a separate library then the web application can use that and provide a common interface to all different knitting application platforms. This is what we have been doing in this GSoC, to provide a common platform and interface for all open source knit app solutions.

So let’s look at the KnitWeb Functionality. KnitWeb consists of two major components, KnitWeb front end and KnitWeb back end logic. KnitWeb front end consists of a pattern editor for edit loaded patterns to workspace, Simulator for show knitting progress and a drawing tool for draw a pattern from scratch. Therefore Pattern editor component is used for easily edit the pattern before send for knitting.

Knitting Simulator is used for render knitting progress to the user with a enhanced user experience. It also consists of main controls for knitting job which user can start/pause/stop a job while knitting.

KnitWeb Drawing tool is used to generate a pattern from a scratch. It provides basic drawing tools including pencil, line, basic shapes and color palette. It also used for replicate a pattern from a existing pattern or a image. Then user can export it to the workspace to continue knitting job.

Pattern Editor Usage

Pattern editor gives following functionality to the users

  • Loads the pattern according to number of rows and columns(stitches) to the editor. Pattern is pixelated as the defined number of rows and columns.

Screenshot from 2015-08-25 08:42:41

  • Select pattern area using square/free hand tools. Then edit colour values of selected area.

Screenshot from 2015-08-25 08:57:28Screenshot from 2015-08-25 08:59:53

  • Show colour regions of selected area/whole pattern and easily edit their colour values.

Screenshot from 2015-08-25 09:08:03

  • Configure machine type and Available ports before creating a knit job. In this step knit web client is communicating with the knit lib server to get those information. After that user can click proceed knitting button to create a knit job.

Knitting Simulator Usage

Screenshot from 2015-08-25 12:14:40

  • Knitting simulator provides knitting progress to the user with enhanced user experience. Current knitting progress is shown to the user as above and also with a progress bar.
  • Knitting simulator window consists of other meta data input needed for configure knitting pattern(knitpat) file such as Start Line, Start Needle, Stop Needle, Number of colours used etc.

Screenshot from 2015-08-25 12:19:33

Drawing Tool

Screenshot from 2015-08-25 12:25:19

  • Drawing tool is used to generate a pattern from scratch or design patterns by replicating image or a texture.
  • After editing finished pattern can be exported to the workspace.

Apart from the above mentioned components edited patterns at the pattern editor can be downloaded as a image file. Also multi-language translation is added by @shiluka to the knit web interface. following is the translation for german language

.Screenshot from 2015-08-25 09:36:08

This sums up the most critical functionalities of knitweb application. I would like to continuously contribute to FashionTec as this inspired me to research and do things that I have not done before. :).

Also here is a little demo on the functionality of knit web. demo link

Thank You 🙂

KnitWeb Localization

Why Localization important

Localization is the process of adapting, translating and customizing a product for a specific locale or cultural conventions. Localization distinguishes a good web front end from a truly successful one. Today English is a priority language to be learning to use computers. Having Localization we can gain benefits such as, no need to local users to learn English first, Reduce amount of training and localization brings additional value. Localization To improve localization community of volunteers needs to get together and first establish a guiding set of terms to guarantee accurate and consistent translation. Community is the strongest part for an Open Source project. Translation process can be improved by making sure that efforts in translations are consistent and structured. So the lots of local users can enjoy KnitWeb and hopefully become a part of the community.

How Localization work on KnitWeb

KnitWeb construct elements of the interface using JavaScript dynamically. Retrieve the correct localized string in JavaScript is the most important part for localize an app like KnitWeb. For the Localization I used 3 types of files i.e., locles.ini and l10.js.

.properties files (, These files contain the translations of strings used in the KnitWeb. Each line is the translation of a single string in “name=value” format; name is an identifier for this string, It is used to map the string; value is the translation of the string in particular language.





locales.ini : locales.ini includes which is the default language in case app does not support current language, what type of other locales KnitWeb supports and the location of the each translated file.

l10n.js: JavaScript library. Automatic localization of strings appearing in your app’s HTML. Provides a JavaScript API your app can use to retrieve localized strings( get, getLanguage, setLanguage, getDirection)

Localization – German
Localization – Sinhala

Exception handler in KnitLib

An exception is an error that happens during the execution of a program. It is important to have exception handler in KnitLib to handle and deal with errors automatically. Many standard libraries define their own exceptions to report errors that may occur in functions they define.  Depending on the kind of error in knitlib (“communication error”, “pattern not found error”, etc.. ). The exception handler module in the knitlib can handle the exception and the knitlib can be continued afterwards with the previously saved data.

Define exceptions as classes

Exception can be defined as classes which do any other class can do, but are usually kept simple, often only offering a number of attributes that allow information about the error to be extracted by handlers for the exception. When creating a library like KnitLib which can raise several distinct errors, a common practice is to create a base class for exceptions and subclass that to create specific exception classes for different error conditions.

Part of the Exception Handler Module, catch exceptions raise from the library

Importance of the test cases for the KnitLib

Having test cases is very important especially for a library like KnitLib because using test cases; we can clearly test particular fields.  In KnitLib, test cases show the information of how the KnitLib should be checked. Also test cases help for new contributors to understand about the KnitLib.

There are several test cases for the current KnitLib implementation such as tests on ayab communication, tests on ayab image, tests on command line interface, tests on KnitPat module and tests on knitting plugin.

For an example in ayab communication there are several important functions have been tested. Test on closing serial port communication, test on opening serial port with a baud rate of 115200 which ayab fits, tests on sending start message to the controller, tests on sending line of data via serial port and tests on reading line from serial communication.  Most of these tests have been done using mock tests. Mock is a python library to test in python.  Using mocks we can replace parts of our system with mock objects and have assertions about how they have been used. We can easily represent some complex objects without having to manually set up stubs as mock objects during a test.

It is very important to improve further test cases on the KnitLib because with the help of good test cases we can guarantee that the KnitLib’s features and functionalities should be working great.