AYAB Hack for Brother Computer Knitting Machines

The goal of the AYAB project is to provide an alternative way to control the famous Brother KH-900-965 knitting machines, use thewhole width of the knitting bed/ 200 needles and an infinite numberof height, lines or rows.

Originally AYAB was developed to work on the KH-910 model, which is far cheaper and numerous than the other models, mainly because it features an error-prone scanner mechanism for reading the image data (but we don't care because we don't use the scanner anyway, nor the computer part either…).

Normally, the KH-910 is programmed using semi-transparent picturecards which are scanned by the machine line by line. Using this information, the machine sets the needles accordingly to achieve the knitting of the picture shown on the picture card. The card is 60 squares wide, so the KH910 machine only supported pictures with a maxof 60 needles (= pixels) width, although the machine has a total width of 200 needles. Though it was possible to mirror the 60 stitches, or to “copy and paste” the scanned image multiple times for a repeating pattern such as for Fair Isle/Norwegian patterns.

With the AYAB interface, you can supply the knitting machine with a digital image from your computer using simple software such as Paint or GIMP, under Windows, Mac and some Linux variants. Thus the restriction of a 60 pixel/needle image width has also simply been abolished due to the vastly improved control that AYAB interface has over the original Brother design. You can now simply knit an image with up to a 200 needle/pixel width.

The control of the needles and the needed identification of the current position and direction of movement of the knitting carriage are supplied by a cheap and well-known Arduino microcontroller, combined with a custom developed shield (the name for an “interface” in the Arduino world) for the knitting machine. You only need to open up one part of your knitting machine and simply replace theexisting control board (the one with all the switches and LEDs on it) with the AYAB controller, then link the Arduino part of this interface (shield) with your computer and start knitting!

The AYAB hack (as we call our Arduino and shield) is non-destructive and fully reversible! Simply remove the AYAB hardware, reconnect the Brother controller and everything is back to its original state, just like in the 1980's!

Most users will just use the provided free AYAB software (open source, regular updates, you are welcome to join!) and do not need to know anything about the details of the Arduino. For those who want to know more, the API (Application Programming Interface) to the Arduino is designed in a simple and straight forward manner, so that the control of the machine can be taken over by almost every piece of knitting machine software which can access the USB port of your computer. The API consists only of three commands (request information about the controller firmware, request the start of a new picture, send line[x] to the controller when the controller requests it)

What you can do with the AYAB:

• AYAB supports the whole width of the needle bed, 200 needles (also called pixels);
• your image can have an infinite numberof rows;
• direct connection to your computer;
• pattern templates can be designed in any graphic program;
• also supports the ribber for Brotherknitting machines. So you can do “Double Bed Jacquard”, amulti-color technique without strands on the back;
• 4-6 colours can be knitted in jaquardtechnique;
• lace knitting is also supported;

Happy knitting!