[Xastir] Xastir Digest, Vol 68, Issue 14

[Dale Seaburg]

David,

Thanks for the reply.  The baudrate in the axports refers to the comm 
speed between the 'sm0' port (in my case) and a tnc via some serial 
port.  See the link: http://www.linux-ax25.org/wiki/AX.25 in the section 
labeled "Creating the /etc/ax25/axports file" where each field is 
described.  The Channel section of the same document mentions the actual 
RF speed (1200 in our case).  The RF speed is not in the axports file.  
But, because I am using a soundcard for my "TNC", that baudrate is a 
moot point.  The soundmodemconfig tool sets the RF baudrate which 
impacts the soundmodem.conf file, independent of the axports file.

Now, on to more interesting findings late last night, or should I say 
early this morning.  I somehow, in my "twisting knobs" (diddling with 
software parms), I lost the ability to decode the incoming packets with 
the smdiag tool.  No matter what I tried it simply would not decode (I 
did not reboot the box, probably like I should have).  I really wanted 
the internal sound card to be my "TNC".

However, I had purchased two of those cheap USB Sound Cards off ebay a 
month or so ago.  So, I hooked one up and did the soundmodemconfig 
thing.  But, I still got some errors that now appeared to gave me a clue 
that the soundmodem app needed to be running as root.  Each of the 
documents I read says to run in user space.  I'm sure that is for 
security purposes.  Phooey on that advice (for now), I did a 'sudo 
soundmodem -M -v 5' and up it came without any errors at all!  YES!  The 
smdiag now decodes beautifully.  So, I brought up xastir and YES, I'm 
seeing stations!  A real plus for the USB Sound Cards, is that the 
associated sound mixer is very simple compared to that gosh-awful, 
complex to the point of being absurd, sound mixer for the internal sound 
card.

The USB Sound Card is not exactly what I wanted, but it works.  BTW, 
those USB Sound Cards are dirt-cheap, like $1.97 buy-now price with free 
shipping.  Beats the price of a h/w TNC!  My plans are for a VOX PTT 
circuit married to the USB Sound Cards similar to the one on G4ILO's 
page:  http://www.g4ilo.com/usblink.html.

Now, when I get some time I will go back and try the internal sound card 
again, this time running the soundmodem as root.

These TC1100 tablet PC's will be deployed for primarily ARES work (real 
emergencies or S.E.T.'s), so security is not an issue.  They do have 
WiFi cards, but those are not configured at this time for use.  They 
probably need a special driver for ubuntu.

Is there a real compelling reason to run soundmodem in user space, other 
than security?

Thanks for the replies, guys.

73 - Dale.  KG5LT


On 7/18/2011 11:00 AM, xastir-request at lists.xastir.org wrote:
> From:
> "David A. Ranch" <xastir at trinnet.net>
> Date:
> 7/17/2011 11:50 PM
>
> To:
> Xastir - APRS client software discussion <xastir at lists.xastir.org>
>
>
>
> For my axports, I have:
>
>    sm0 KI6ZHD 1200 255 2 144.390 MHz (1200 bps)
>
> The biggest point I see is the baud rate in your config file is set to 
> 4800 when it should be 1200.  Btw, I *had* to use the mkiss module or 
> the system load would go to 100%.
> If everything loads up seemingly ok, what do you see in 
> /sbin/ifconfig?  You might not be getting the sm0 device name you expect.
>
> If it helps, I have my config files here ( 
> http://www.trinityos.com/HAM/CentosDigitalModes/etc/ax25/ ) and also 
> my master startup script ( 
> http://www.trinityos.com/HAM/CentosDigitalModes/usr/local/sbin/packetrig.sh 
> ) that might also help.
>
> --David
>
>
>
> Dale Seaburg wrote:
>> Got a problem with ax25 and soundmodem install on a xubuntu 10.04 LTS 
>> box (HP TC-1100 tablet).
>>
>> Using the Synaptic Package Manager (gui apt-get), I had installed 
>> ax25 stuff and soundmodem stuff */after/* I had installed xastir.  
>> So, xastir did not have the necessary parts loaded.  After realizing 
>> this, I ran the update-xastir script and now ax25 parts are included 
>> in xastir to where I see the interface when I add an AX25-TNC.  So 
>> far so good, or so I thought.
>>
>> BTW, I am following the steps in the xastir wiki: HowTo AX25 and 
>> HowTo Soundmodem.
>>
>> I have run the soundmodemconfig program to setup the soundmodem with 
>> the interface name of 'sm0' and mode of MKISS.  When testing with the 
>> Diagnostics tab of that same program, I see APRS packets decoded, and 
>> hear the brab in the speaker.  So I know the soundmodem is working in 
>> the receive section.  The transmit will be next after I solve the 
>> receive problems.
>>
>> I start xastir and go to the Interface tab.  I have the AX25-TNC 
>> already added, but, the AX25-TNC will not come up when I click the 
>> Start button.  I see this error in the terminal window in which I 
>> start xastir:
>>
>> axconfig: port sm0 not active
>> ERROR: problem with axports file
>> Sun Jul 17 20:36:23 CDT 2011:
>>     Interface Error!  AX.25 problem with axports file
>>
>> Sun Jul 17 20:36:23 CDT 2011:
>>     Interface Error!  Error opening interface 0 Hard Fail
>>
>> Here is the axports file in /etc/ax25:
>>
>> # /etc/ax25/axports
>> #
>> # The format of this file is:
>> #
>> # name callsign speed paclen window description
>> #
>> #1    OH2BNS-1    1200    255    2    144.675 MHz (1200  bps)
>> #2    OH2BNS-9    38400    255    7    TNOS/Linux  (38400 bps)
>> sm0    KG5LT-2        4800    256    7    144.390 MHz (1200 bps) APRS
>> #sm0    K5BWD-2        4800    256    7    144.390 MHz (1200 bps) 
>> Radiogram
>>
>> I also see (before bringing up xastir) in the terminal window I use 
>> to bring up soundmodem these errors (with or without the -M option).  
>> The smstart.sh script is: soundmodem -M -v 5:
>>
>> barc at tc1100-dev:~$ ./smstart.sh
>> sm[1936]: kiss: symlink error: /dev/pts/2 -> /dev/soundmodem0
>> sm[1936]: audio: starting "/dev/dsp"
>> sm[1936]: audio: forcing half duplex mode
>> sm[1936]: audio: sample rate 9600 input fragsz 256 numfrags 128 
>> output fragsz 256 numfrags 128
>> sm[1936]: mlockall: Cannot allocate memory (12)
>>
>> What might I be doing wrong?  I see no reference in either the AX25 
>> or soundmodem HowTo that talks about the seeming need for a symlink.  
>> Am I missing something.  Are the HowTo's missing something?  It would 
>> seem that the symlink error and the sm0 port not active error are 
>> related?
>>
>> Anyone with experience?  It can't be that difficult, but right now, 
>> I'm blind-sided.  I want to use the MKISS rather than the KISS 
>> interface.  I have not tried the KISS interface, IIRC.
>>
>> I'll be glad to pass along any other bits of information as needed.
>>
>> I'm open to words of wisdom...
>>
>> 73 - Dale.  KG5LT