Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 347 — #373

Linux on Mobile Devices

an IrDA-compatible transceiver that enables communication with other de-

vices, such as printers, modems, LANs, or other laptops. The transfer speed

ranges from 2400 bps to 4 Mbps.

There are two IrDA operation modes. The standard mode, SIR, accesses the

infrared port through a serial interface. This mode works on almost all sys-

tems and is sufﬁcient for most requirements. The faster mode, FIR, requires

a special driver for the IrDA chip. Not all chip types are supported in FIR

mode because of a lack of appropriate drivers. Set the desired IrDA mode

in the BIOS of your computer. The BIOS also shows which serial interface is

used in SIR mode.

Information about IrDA can be found in the IrDA how-to by Werner

Heuser at http://tuxmobil.org/Infrared-HOWTO/Infrared-

HOWTO.html. Additionally refer to the web site of the Linux IrDA Project

at http://irda.sourceforge.net/.

16.3.1 Software

The necessary kernel modules are included in the kernel package. The

package irda provides the necessary helper applications for supporting

the infrared interface. The documentation can be found at /usr/share/

doc/packages/irda/README after the installation of the package.

16.3.2 Conﬁguration

The IrDA system service is not started automatically by the booting pro-

cess. Use the YaST runlevel module to change the settings of the system ser-

vices. Alternatively, use chkconfig. Every few seconds, IrDA sends out a

“discovery packet” to detect other peripheral devices in its neighborhood.

This consumes a considerable amount of battery power. For this reason,

IrDA is disabled by default and should only be started when needed. Man-

ually activate it with rcirda start or deactivate it with rcirda stop.

All kernel modules needed are loaded automatically when the interface is

activated.

The ﬁle /etc/sysconfig/irda contains only the one variable IRDA_-

PORT. This is where the interface used in SIR mode is set. The script /etc/

irda/drivers of the infrared support package sets this variable.

347SUSE LINUX Enterprise Server