Knit yourself a computer with the Lilypad Arduino

Arduino kits are the go-to tool for many DIY wiring and computer projects, and the same is true for knitting. One of the best known Lilypad Arduino projects is Kalani Craig's pattern "Know It All" which was published by Knitty.

Know-It-All is a felted bag which acts as a row counter and knitting chart minder. You program it with your knitting pattern (up to 10 stitches across), and a row of ten LEDs displays your chart. (A steady light is a knit stitch, an off light is a purl stitch, a fast blink is a yarnover, etc.) It has a push button, which you press to advance your pattern. A Lilypad Arduino serves as the controller, with its microcontroller board.

Confused? You can see it all in action here, in a short video in which Kalani Craig describes how the whole thing works, and demonstrates its use.

How is all this possible?

The Lilypad Arduino was created by Leah Buechley, an Associate Professor at the MIT Media Lab, specifically designed for use in textiles. It's not just small, flexible and cute, it's also washable (although you should wash it gently to be on the safe side). Other Lilypad projects include a jacket with a turn signal sewn into the back, for use by bicycle riders, and a flower lapel that changes color as you move (thanks to the accelerometer add-on).

Image of Lilypad Arduino controller board courtesy Flickr/jeanbaptisteparis

The Lilypad is one of many different forms of Arduino microcontrollers which were developed for hobbyist robotics in 2006. Arduino kits have been used by enthusiasts around the world to create amazing works of computational joy. You "talk" to an Arduino board by installing the Arduino software on your computer, writing your program, then connecting your computer to the controller via USB in order to transfer the program to the Arduino.

Image of Lilypad Arduino receiving instructions courtesy Flickr/Rain Rabbit

Arduino programming was designed to be simple for non-programmers to learn and use. It's written in a Java environment, and includes a software library for most of the more common applications you might want. (Luckily for knitters, Kalani Craig includes the Arduino programming file along with her knitting pattern, so that you do not have to write any code in order to get your Know-It-All bag working.)

The second technological advance that makes the Know-It-All possible is conductive thread. This too was designed to be used in textiles, which means that it can be (gently) washed. It connects the Lilypad to the LEDs, and you can sew with it just as you would an embroidery thread.

Image of Lilypad and conductive thread courtesy Flickr/sameerhalai

Craig has done some testing and experimentation, and found that the greatest problem with using conductive thread in textiles is that if the fabric (and the conductive thread) shifts around too much, short circuits can form. This is why she has chosen to make Know-It-All a felted project: The thick felted wool provides the stability that a regular knit fabric would lack.

In order to avoid short circuits, you will also need to use a bit of care in sewing the conductive thread and connecting all the various parts. Craig has included a great deal of valuable information in this regard - just follow the instructions and you should be fine.

From a technical knitting standpoint, actually creating the Know-It-All bag is, as Craig points out, not very difficult. If you can knit, felt, and do some basic seaming, you have all the skills you need to create the bag. Craig's instructions are laudably clear and concise.

You don't need to specifically make a bag, either. I love the idea of a knitting bag that helps you knit, but I have trouble envisioning myself sitting on the couch consulting a felted bag for my pattern. Any felted item that has enough room for both the Lilypad Arduino and the row of LEDs will work for this project. Personally I would love to see this as a Leela-style arm cuff, a felted box, or even a large felted pendant that you could wear as a necklace.

It goes without saying that the Lilypad Arduino has a lot of applications for knitting patterns that have yet to be explored. I'll tell you what I would really like… a felted bag that outputs my grocery list. There's something that I would use regularly!

Main image copyright Kalani Craig/Knitty.com