Making Things Talk

116 MAKING THINGS TALK

Introducing Network Modules

There are many such modules on the market, with varying

prices and features. Just as you can choose how technical

you want to get when you pick a microcontroller platform,

you can also choose your technical level when you pick a

network controller. Some modules, like Rabbit Semicon-

ductor’s RabbitCore processors, come with all the source

code for a TCP/IP stack, and expect you to modify it for

your needs and program the device yourself. This module

is powerful, but has a steep learning curve. Others have a

stack programmed into their firmware, and present you

with a serial, telnet, or web-based interface. These are

much simpler to use. The web interface gives you access

from the browser of your personal computer; the telnet

interface gives you access from a server or your personal

computer; and the serial interface gives you access from a

microcontroller.

In the past few years, a wide array of commercial appli-

ances has come on the market that can connect directly

to the Internet without the aid of a personal computer.

Companies like D-Link, Sony, Axis, and others make

security cameras with network interfaces, both Ethernet

and Wi-Fi. Ceiva, eStarling, and others make picture

frames with Wi-Fi connections to which you can upload

images from the Net. Ambient Devices makes lamps and

displays of various sorts that connect to the