Page 353 - Hacking Roomba

334 Part III — More Complex Interfacing

This chapter uses many of the same techniques of installing the OpenWrt embedded Linux
from Chapter 14. Installing and configuring OpenWrt is very similar on the various routers it
supports. Refer to Chapter 14 for details on getting OpenWrt running for the first time.

Parts and Tools

The parts for this project are:

Linksys WRTSL54GS wireless router, Newegg N82E16833124057
Creative Instant Webcam, or equivalent, Newegg N82E16830106120
USB flash drive, any capacity, Newegg N82E16820211027
USB hub, 4-port travel size, Newegg N82E16817201604
Generic USB-to-serial adapter, or USB dongle (see sidebar below)
Power plug, standard barrel connector, Radio Shack part number 274-1569
9V battery snap connector, Radio Shack part number 270-325
8-cell AA battery pack, Radio Shack part number 270-407
Eight AA cells, 2700 mAh NiMH, SparkFun part number Batt-NiMH
1N4004 diode, Radio Shack part number 276-1103

It turns out all the component parts for this project are available from Radio Shack. The AA
cells should be rechargeable, and preferably the nice 2700 mAh NiMH batteries from
SparkFun should be used.

Upgrading the Brain

Even though an entirely different wireless router from a different vendor is being used, the
underlying chipset is essentially the same. Thus any binaries you have from the previous project
will work in this one, too. And since you’re using OpenWrt, much of the configuration is the
same as in the previous project.

Linksys WRTSL54GS

The WRTSL54GS (or SL because the name is so ungainly) is composed of a 266 MHz CPU,
8 MB flash and 32 MB RAM. So it’s essentially double everything the Asus WL-HDD is,
except the price. The SL can be had for a little over $100, whereas the WL-HDD can be
found for around $70. The SL is a little bigger. It’s shown in Figure 15-1, and you can see the
USB port that makes it so interesting compared to other wireless routers.