Zipper Switch

2023-03-07 | By Adafruit Industries

License: See Original Project Wearables FLORA Gemma

Guide by Becky Stern

Overview

Here’s a fun way to make your clothes more interactive-- you can ‎turn a zipper into a switch for activating lights, sounds, and more ‎using stainless steel conductive thread.‎

zipper_1

The switch works like a momentary pushbutton. As the zipper pull ‎travels along the teeth, two pads of conductive thread are bridged, ‎momentarily creating an electrical connection.‎

This connection can be sensed by a microcontroller like FLORA or ‎GEMMA with an activated internal pullup resistor or be used in place ‎of a push button in circuits like the TV-B-Gone or audio FX boards.‎

The zipper switch is not delivering current and should not be used to ‎drive LEDs-- it's a very weak connection that is only made ‎momentarily and not suitable for more than a few milliamps of ‎current.‎

metal_2

Find a metal zipper pull, not plastic. If it’s painted, use some ‎sandpaper to sand it off.‎

find_3

The teeth of the zipper can be plastic or nylon, so long as the zipper ‎pull is metal!‎

Stitch long strands

stitch_4

Use straights stitches to bring two long pieces of conductive thread ‎to the edge of the zipper.‎

sew_5

You can put 2-ply thread in the bobbin of your sewing machine, then ‎pick up long tails with a needle and hand-stitch the rest.‎

Stitch pads near zipper

pads_6

Build up stitches to make two small pads of thread. They should be ‎close enough together that when the pull goes by, it briefly touches ‎both pads at once.‎

build_7

You want the knots away from the zipper, so stitch a bit back and tie ‎off, then seal with a dab of clear nail polish. Let it dry before cutting ‎the thread short.‎

polish_8

Attach to circuit

attach_9

At the other ends of the thread, stitch one to ground and the other to ‎a digital input on your FLORA or GEMMA microcontroller.‎

ends_10

Don’t forget to activate the internal pull up resistor when you set up ‎your Arduino sketch.‎

‎Download File‎

Copy Code

void setup(){
  pinMode(1, INPUT_PULLUP);

}

Use it!‎

use_11

It acts like a momentary switch. You can use a zipper switch in place ‎of a pushbutton, like in this TV-B-Gone jacket.‎

push_12

I stitched this a few years ago with silver conductive thread, and it’s ‎tarnished. That’s why we carry only stainless-steel thread! It’s a little ‎more expensive but will last a lot longer.‎