Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 349 — #375

Linux on Mobile Devices

Check the conﬁguration of the interface if there is no output or the other

device does not reply. Verify that the correct interface is used. The infrared

interface is sometimes located at /dev/ttyS2 or at /dev/ttyS3 and

an interrupt other than IRQ 3 is sometimes used. These settings can be

checked and modiﬁed in the BIOS setup menu of almost every laptop.

A simple CCD video camera can also help in determining whether the in-

frared LED lights up at all. Most video cameras can see infrared light; the

human eye cannot.

16.4 Bluetooth — Wireless Connections

Bluetooth is a wireless technology for connecting various devices. Two im-

portant characteristics distinguish Bluetooth from IrDA: the individual de-

vices do not need to “see” each other directly and several devices can be

connected in a network with a maximum data rate of 720 Kbps (in the cur-

rent version 1.1). Theoretically, Bluetooth is even capable of communicating

through walls. However, in practice this largely depends on the properties

of the walls and the device class. There are three device classes with maxi-

mum transmission ranges between ten and a hundred meters.

16.4.1 Proﬁles

In Bluetooth, services are deﬁned by means of proﬁles, such as the ﬁle

transfer proﬁle, the basic printing proﬁle, and the personal area network

proﬁle. To enable a device to use the services of another device, both must

understand the same proﬁle — a piece of information that is often miss-

ing on the device package and in the manual. Although some manufactur-

ers strictly comply with the deﬁnitions of the individual proﬁles, others do

not. Nevertheless, the communication between the devices usually works

smoothly.

16.4.2 Software

To be able to use Bluetooth, you need a Bluetooth adapter (built-in or exter-

nal), drivers, and a Bluetooth protocol stack. By default, the Linux kernel

contains the basic drivers needed for using Bluetooth. The Bluez system

is used as protocol stack. Additionally, install all packages associated with

Bluetooth (bluez-libs, bluez-bluefw, bluez-pan, bluez-sdp, and

bluez-utils), as these provide some necessary services and utilities.

349SUSE LINUX Enterprise Server