Technique Report:The Replaceable Lilypad

purpose:

• lilypads don’t live forever -

• battery accidents can be fatal

• Exposed electronics on your clothes are an accident waiting to happen (especially in this context, for a dancer, where the lilypad is subject to intense physical activity).

• Quickly switch out different programs, without interfacing with Arduino

step 1: solder loops to lilypad

It can take some patience aligning the loops with the terminals, but they solder pretty nicely.

Next, I cut out a piece of 5”x5” (or so, depending on application) pieceof fabric.

I eyeballed 22 button snaps along the edge (5 or 6 per side)

Then, I marked the locations of the buttons on a piece of paper

Then, I cut out a piece of 5”x5” conductive fabric, ironed it to an iron-on sheet, and markedthe location of the buttons on the rear side.

I traced the lilypad in the center.

And I marked the locationeach solder terminal on thepaper

Next, I drew the desired shape of the conductive fabric

I cut out the shapes, and ironed them onto the original piece of fabric

I began sewing the hooks to the fabric

and attaching button snaps

Here it is more or less finished. Unfortunately I ran out of both snaps and hooks part way through.

Here it is with the lilypad hooked in

next stepsIn retrospect, I realize that I created a redundant dual modularity -The entire unit and the lilypad itself are both removable. It makes more sense to have the lilypadsewn into the conductive fabric, then to create many of these interfaces, such that one can be snapped out and another snapped in. In this situation, there is no need for the lilypad to be modular.

So, the next step is to create and Illustrator vector file of the conductive fabric layout, and to create several more of these. From now on I’ll be sewing the lilypad into the fabric.

**However, I think the hook and loop technique was effective, and could be applied in other situations. lilypad sells several sensors with the same circular layout, so this technique could be good for making modular sensors. I have since used it to make a modular accelerometer (see final project presentation).