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238 Part III — More Complex Interfacing

ant.
reset
leds sw
2 1 GND 2 1 5Vin
4 3 (output) TXA 4 3 RXA (input)
6 5 (output) DTRA 6 5 RTSA (output)
8 7 (input) DCDA 8 7 CTSA (input)
10 9 WiPort /RESET 10 9 RVA/TX_EN
12 11 (output) TXB 12 11 RXB (input)

FIGURE 12-4: Pinout and location of WiMicro header (top view)

Lantronix doesn’t produce a single document on how to use and configure the WiMicro. Instead
you must download several different documents, most for the WiPort. Particularly useful is the
WiPort User Guide (WiPort_UG.pdf), which describes how to configure the device, and the
WiMicro Addendum (WiMicro_Addendum.pdf), which goes over the layout of the WiMicro
board.

DPAC Airborne and Other Wireless Device Servers
There aren’t as many Wi-Fi device servers as there are Ethernet ones. This is unfortunate since
Wi-Fi is much more interesting. The devices that do exist are bulky like the WiMicro. For
example, another company called Digi (www.digi.com/) makes the Wi-ME (www.digi
.com/products/embeddedsolutions/digiconnectwime.jsp). The Wi-ME is very
similar in terms of usage, power, and cost to the Lantronix WiPort or WiMicro. There’s not as
much hacker-friendly information about it on the Internet, however, so using the WiMicro is
easier in that respect.

An interesting device that is just now making its way into the hobbyist space (thanks to SparkFun)
is the DPAC Airborne embedded server. This is a truly tiny device, at only about an inch square
(see Figure 12-5). In large quantities they cost about $80 a piece. In small quantities you can
get them for $125 from SparkFun. SparkFun also makes them a little easier to interface to by
offering a $15 breakout board that converts the high-density connector to a useful 0.1˝ header.
To properly experiment with the Airborne module, you get the evaluation kit. This kit is large
not only in price ($479) but also in size (see Figure 12-6). It’s unfortunate that DPAC doesn’t
do what Lantronix did with the WiMicro, which is just a packaging of the WiPort. A small,
experimenter-friendly drop-in board would make it easier to use.