evad.zone

Recently I was faced to the problem of buying cellular modem on PCMCIA/CardBus interface for my laptop. One of the minimum requirements was Linux support – of course. I have found really good deal on Sierra AirCard 850 wireless GPRS/EDGE/UMTS/HSDPA modem, and I also was more than happy to learn that it has (unofficial) Linux support. Well, once card has arrived, it turned out ‘Linux support’ wasn’t that straightforward, and I was really struggling to get it working, but finally I’ve succeeded.

First of all, we need to completely forget about manufacturer’s solution. It was written quite long time ago, for old kernels. Nowadays kernels are supporting PCMCIA interface in a bit different way, and this is why we need to fix the problem in other way.

Second of all, download a file from Sierra’s website. It contains SW_8xx_SER.dat file. Rename it to SW_7xx_SER.cis and place in /lib/firmware directory. After rebooting the computer, card should be recognized automatically once it’s inserted into slot. You can check it with dmesg:

[root@dell620 ~]# dmesg
[...]
pccard: PCMCIA card inserted into slot 0
cs: memory probe 0xa0000000-0xa0ffffff: clean.
pcmcia: registering new device pcmcia0.0
0.0: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A

Basically, card is recognized as new serial device /dev/ttySX, so you can now add it as new modem and network interface – check out one of my previous entries to get the idea how to do it.

AT Commands Reference

Somewhat off-topic, but still interesting – this modem has quite extensive set of AT commands, which can be used for diagnosing modem status, possible network problems, or even force modem to use particular band. You can communicate with modem using minicom – for example. However, it is not possible to communicate with modem simultaneously with PPP connection. :(

Download: Sierra’s AT Commands Reference (thx to ST)

Sources:
http://lists.opensuse.org/opensuse/2006-07/msg01866.html
http://umtsmon.sourceforge.net/cards/sierra_wireless_aircard_775.shtml

This entry was posted on Wednesday, May 23, 2007 at 8:12 and is filed under Linux. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.