Hardware Hacking Projects for Geeks

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Part II: Advanced Hacks, Tools, and Techniques

Project Overview

A basic wearable system will likely have a central processor unit, a display

(usually mounted over one eye), a user input device, a mass storage device,

and some sort of power source. This is by no means an exhaustive list, just

a general guideline.

You can see several typical components and how they might be connected

in Figure 14-1. This particular setup is not the only way to connect the

components. You will construct your system based on the components you

choose and connect them to suit your needs.

Before you build your wearable system, you might want to take a look at

what others have done already. A number of wearable projects are listed at

the end of this chapter.

Hardware Assembly Instructions

You can choose from a large number of available components to add to your

wearable system. However, the basic components you will need to complete

this hack include:

CPU

Battery

Accessories

User input device

Head mount display

Figure 14-1: Wearable overview

Project Overview

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Chapter 14, How to Build a Wearable Computer

• A display

• A CPU and motherboard

• A power system

• Human input and control devices

• Communications interfaces

• Data and program storage devices

• Sensors and I/O devices

The following sections cover each component system and describe how

they can be assembled.

Display

When people think about a wearable computer, often the first thing that

comes to mind is some sort of eyepiece display. This type of display allows

hands-free operation and keeps whatever you are looking at private. An

eyepiece display is often called a head-mount display or HMD. This display

will probably be the most expensive part of your system.

If the “Borg” look doesn’t appeal to you, you can just as easily choose a

small LCD display that is strapped to your arm or held inside a pouch or

bag. This small display can then be brought out when needed and stored

away when not in use.

Many of the lower-cost displays available are low resolution, at least com-

pared to desktop or laptop monitors. This means you will need to carefully

arrange your desktop icons (if you are using a Windows-based frontend to

your operating system) or carefully partition your interface to fit in your

most used programs.

Today, a number of companies make HMDs that can be useful for building

your own wearable computer. The following list describes three that seem

quite interesting and are not outrageously expensive. But note that the

HMD market changes quite a bit, and there may be other companies out

there with new products.

I-Glasses. The I-Glasses product line offers a reasonably priced HMD that

accepts and displays either SVGA or NTSC video signals, depending on

the model you choose.

These displays cover both eyes when worn, so obviously they aren’t suit-

able for use while walking or engaging in any activity other than using

your wearable. You can see both models in Figures 14-2a and 14-2b.

They can be purchased for less than $1,000 from http://www.i-glasses.

com/.

Head-Mount Displays

A number of companies have

attempted to produce consumer-level,

head-mount displays, but most have

stopped manufacturing due to lack of

consumer demand. One of the first

companies to produce a relatively

inexpensive HMD was the Phoenix

Group with its Private Eye. This

device, though no longer available,

worked by moving a column of 240

LEDs back and forth across your field

of vision 30 times per second, provid-

ing a display area of 720 horizontal

pixels. The display allowed only a

single color, red, but was relatively

inexpensive (less than $1,000) and

was built for wearable applications.

Figure 14-2a: iGlasses NTSC

Figure 14-2b: iGlasses SVGA

Hardware Assembly Instructions

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