Wearables: First Steps

Intro

This is an introduction to working with soft electronics.Combining and entwining circuits and fabrics. We will go trough the fundamental knowledge of electricity and how we can use it in various ways to make soft interfaces.

Hello wolrd: Soft circuit

For the hello world we will use an led as an output. A light-emitting diode (LED) is a two-lead semiconductor light source. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. (https://en.wikipedia.org/wiki/Light-emitting_diode) There are two things we have to take care when using LED. – LED has polarity. Make sure to connect LED in correct direction. You can tell the direction as the positive side usually has a longer leg, or a smaller triangle lead in the epoxy lens. Or a dent in the epoxy on the negative side. How much voltage and current does LEDs require to light up? It depends on the LED and you will need to check its datasheet to know exact specification. The voltage you need is called “(forward) voltage drop” and the current required is called “forward current”. Most of the normal (not super bright) LEDs light up somewhere around 2-2.5v and require 20-30mA.

– You will need to limit the current to suitable range. you can read here “why?” >> To limit the current, you need to add resisters in your circuit. You can calculate it yourself using Ohm’s law, or use online calculators like this one >> http://led.linear1.org/1led.wiz

simple

Lets s start my making the hello world of soft and any kind of circuitry:) And use the led we talked so much about.

Cut conductive fabric that has fusible interfacing on one side. peel off the backing paper and place it on base fabric. Make sure the iron is set to synthetic. Most conductive fabric is delicate. And you do also rist the glue from the interfacing glue to appear of the front.

You can cut each side or fold to make corners. In both cases we need to check if all connections are right. We will use the continuity setting.

We make a rectangular shape and leave both sides open. On one side we will clamp the battery, and on the other: sew the led.

Use pliers ( best rounf ones) to bend the led legs into hooks. That way it will be easy to sew.

Then we will use a clip to hold the battery in place.

Many options are possible of course. Both in materials and design. But we have to get started,

You can also use conductive thread to make the circuit.