Making Things Talk

WIRELESS COMMUNICATION 217

In Project #5, you connected a microcontroller to the

internet using a Lantronix Micro serial-to-Ethernet module.

You could replace the Micro with a WiMicro and build the

exact project, with only some minor configuration changes

on the WiMicro.

It’s worth mentioning why Wi-Fi isn’t more pervasive in

embedded wireless projects. First, there’s the cost. Most

of the serial-to-Wi-Fi modules on the market are more

expensive than equivalent transceivers implementing

other protocols. For example, the WiMicro costs about

$165. DigiConnect’s equivalent module, the plaintively

named Wi-ME, costs about $130. Other wireless Ethernet-

to-serial modules on the market are in the same price

range — over $100. When compared to $20 for XBee and

other serial transceivers, or even the $60 price range

typical for many Bluetooth modules, Wi-Fi isn’t exactly

a bargain.

Besides the cost, however, there’s another factor to

consider before going Wi-Fi. Most Wi-Fi modules consume

more electrical power than the other radio types

mentioned here. Because one of the main reasons for

going wireless is to go mobile, you’ll be eating up battery

life with Wi-Fi radios. So they’re great when they’re conve-

niently already built into a product, but if you’re building

from the ground up, it’s worth considering other alterna-

tives. One common solution for wireless projects that

need Internet ...