HacDC Wiki - User contributions [en]

Meeting Agenda 2008 12 09

2011-04-18T05:57:26Z

Happyfine:

{{Floating TOC}}
== Time & Location==

: December 9, 2008
: 7:30
: HacDC, 1525 Newton St NW, Washington, DC. (Space)

== Draft minutes of the last meeting ==

Tentatively approve [[Regular_Member_Meeting_Minutes_2008_12_02 | Draft Minutes of the Dec 2 Meeting]]

== The Consent Agenda ==

(No items submitted in time to meet Consent Agenda Rules)

== Minister Reports ==

* [[Coordinator-in-Chief]] : Elliot Williams
* [[Minister of Finance]] : Nick Farr
* [[Minister of Information]] : Katie Bechtold
* [[Keeper of The MIBS]] : Richard Bewley

The jackets of Abercrombie are http://www.thomasaboshop.com/thomas-sabo-jewelry.html produced for males belonging to numerous walks of life. They have in no way been specified for males who belong to some particular profession. They could possibly be used even although you are stepping away from your real estate property property for buying and even in the time as quickly when you are http://www.thomasaboshop.com/thomas-sabo-necklaces.html steering to go to an informal purpose or party. These jackets would go with you in every one of the way. You can place on them all through evening and even at night. everyone will appreciate your taste from the choice of jackets.

It persists to be lots of years, because http://www.thomasaboshop.com/thomas-sabo-bracelets.html when Abercrombie and Fitch jacket persists to be producing males a complete great offer more trendy and sophisticated. Abercrombie and Fitch will be the brand, which has in no way believed in http://www.thomasaboshop.com/thomas-sabo-watches.html developing loud jackets for men, but this http://www.thomasaboshop.com/thomas-sabo-earrings.html producer has consistently prioritized decency in its developing and also this could be the reason, why a tremendous amount of males are attracted over the types of Abercrombie jackets.

== Old Business ==

The colours of those jackets are http://www.billigetiffanysalg.com/tiffany-armringe.html quick as well as on washing them, they are not faded. You will see how the fabric, which http://www.billigetiffanysalg.com/tiffany-smykker.html could be employed from the producing of jackets, is extremely durable. It suggests that Abercrombie and Fitch provides worth to preserve up the high quality needs and also this could be the reason, why their purchasers experienced been transformed http://www.billigetiffanysalg.com/tiffany-gennemse-pengeclips.html to loyal customers. These jackets are supplied in numerous colours also it may help you, in choosing the just one of your personal choice. if you actually http://www.billigetiffanysalg.com/tiffany-tilbehor-gaver-til-ham.html are also amid the fans of Abercrombie jackets, then you http://www.billigetiffanysalg.com/tiffany-gennemse-nogleringe.html certainly can very easily purchase just one for yourself, from Abercrombie and Fitch outlet or you also can purchase them, over Internet.

=== [[Main Space Reconfiguration]] ===

Nick, Nate and others will present their plan for reconfiguring our present space over the coming week. A tentative budget for the project will be presented.

== New Business ==

* Notification of appointment of Shadow Ministers
** [[User:Q|Andrew Righter]], Shadow Minister of Special Projects
* Renew [[Nate_B_Dues_Waiver | Nate B's dues waiver]] to January 31, 2010.
* Admit new members, if any

[[Category:Meeting_Agendas]]

Meeting Agenda 2008 12 09

2011-04-18T05:55:40Z

Happyfine:

{{Floating TOC}}
== Time & Location==

: December 9, 2008
: 7:30
: HacDC, 1525 Newton St NW, Washington, DC. (Space)

== Draft minutes of the last meeting ==

Tentatively approve [[Regular_Member_Meeting_Minutes_2008_12_02 | Draft Minutes of the Dec 2 Meeting]]

== The Consent Agenda ==

(No items submitted in time to meet Consent Agenda Rules)

== Minister Reports ==

* [[Coordinator-in-Chief]] : Elliot Williams
* [[Minister of Finance]] : Nick Farr
* [[Minister of Information]] : Katie Bechtold
* [[Keeper of The MIBS]] : Richard Bewley

The jackets of Abercrombie are http://www.thomasaboshop.com/thomas-sabo-jewelry.html produced for males belonging to numerous walks of life. They have in no way been specified for males who belong to some particular profession. They could possibly be used even although you are stepping away from your real estate property property for buying and even in the time as quickly when you are http://www.thomasaboshop.com/thomas-sabo-necklaces.html steering to go to an informal purpose or party. These jackets would go with you in every one of the way. You can place on them all through evening and even at night. everyone will appreciate your taste from the choice of jackets.

It persists to be lots of years, because http://www.thomasaboshop.com/thomas-sabo-bracelets.html when Abercrombie and Fitch jacket persists to be producing males a complete great offer more trendy and sophisticated. Abercrombie and Fitch will be the brand, which has in no way believed in http://www.thomasaboshop.com/thomas-sabo-watches.html developing loud jackets for men, but this http://www.thomasaboshop.com/thomas-sabo-earrings.html producer has consistently prioritized decency in its developing and also this could be the reason, why a tremendous amount of males are attracted over the types of Abercrombie jackets.

== Old Business ==

=== [[Workshop Configuration]] ===

Nick, Nate and others will present their plan for reconfiguring the new workshop space over the coming week. A tentative budget for the project will be presented.

=== [[Main Space Reconfiguration]] ===

Nick, Nate and others will present their plan for reconfiguring our present space over the coming week. A tentative budget for the project will be presented.

== New Business ==

* Notification of appointment of Shadow Ministers
** [[User:Q|Andrew Righter]], Shadow Minister of Special Projects
* Renew [[Nate_B_Dues_Waiver | Nate B's dues waiver]] to January 31, 2010.
* Admit new members, if any

[[Category:Meeting_Agendas]]

Notes on Soundmodem

2011-04-18T05:50:34Z

Happyfine:

[http://www.baycom.org/~tom/ham/soundmodem/ Soundmodem] emulates a hardware modulator/demodulator in software, vis a vis a daemon running in userspace.

v0.15 is the latest, I recommend using that. v0.14 requires libxml, which I don't think anybody makes available anymore. libxml2 is used for storing the config file in /etc/ax25.

Soundmodem will either turn your soundcard into a KISS radiomodem or an AX.25 network interface. We're going to be working with the AX.25 side of the house.

= Installation =

There are many different sorts of http://www.tiffanyandconline.com/tiffany-pendants.html jackets inside the Abercrombie's guys jacket collection. one of the most favored and marketed out sort is of that of Abercrombie fur jacket. These jackets are well-known for a lot of different prospects to and therefore are wanted by any youthful dude since the level of quality belonging toward fur http://www.tiffanyandconline.com/tiffany-keys.html they use for that manufacture of those jackets is really genuine. The fur is inside the finest of skins and is also utilized wisely and finely. It is not even unhygienic. This fur is made and utilized in a different way and with decency so if anybody would like to actual appearance genuinely brilliant and completely different amid his buddies he really should purchase an Abercrombie fur jacket.

Any Abercrombie men's jacket which consists of Abercrombie fur jacket is stylish however really comfortable. The comfort ought for getting offered to their http://www.tiffanyandconline.com/tiffany-earrings.html consumers could possibly be the motto of the style retailer. developing jackets which could be each comfy and stylish is genuinely a job Abercrombie Fitch have been executing offered that it absolutely was founded. From then, the level of quality of the jackets have been consistent. They http://www.tiffanyandconline.com/tiffany-bangles.html by no signifies compromise using the excellence and comfort belonging toward jackets. These two features make these jackets lengthy lasting impressive. As these http://www.tiffanyandconline.com/tiffany-watches.html jackets by no signifies loose their essence and therefore are typically in fashion, just one may properly be as very much as dated by style trends if just go using the choice Abercrombie Fitch offers.

== Apt-Get: Ubuntu Lucid and Up ==
Gets you version 0.13 on Lucid, and 0.15 on Maverick and Natty

As root do the following
<pre>
apt-get install soundmodem
mkdir /etc/ax25
soundmodemconfig /etc/ax25/soundmodem.conf #see below for configs
soundmodem /etc/ax25/soundmodem.conf -R -M >/dev/null 2>/dev/null& #this makes an awful noise when it works
</pre>

==On Fedora==
???

= Configuration =
== IO Tab ==
On the I/O tab, choose your sound driver (out of soundcard, file, simulation, and alsa, I picked alsa). You'll have to play around with the value of the ALSA Audio Driver field to get one that works. On Windbringer, I used plughw:0,0. Check half duplex for now. Leave the Capture Channel field set to 'mono'. I don't know what to set the PTT Driver field to yet, so I left it on 'none'.

It's possible that we'll have to develop some sort of [http://www.baycom.org/~tom/pcf/ptt_circ/ptt.html serial or USB push-to-talk interface] for the comm system, or use full duplex with two radios, using one to transmit and one to receive. We could rig up PTT circuits with microcontrollers, build a known circuit (like the serial port or VOX one from the above link), or evade the problem entirely.

== Channel Access Tab ==
Don't change the settings on the Channel Access tab.

== Channel 0 ==
Right below the name of your configuration in the tree you will see a new entry, Channel 0. If you select it you'll be presented with three new tabs on the right.

=== Modulator Tab ===
The possible values for the Mode selector are Off, fsk, afsk, pam, psk, and newqpsk. I picked afsk because [http://www.xastir.org/wiki/HowTo:SoundModem the Xastir wiki told me so]. I left the values for Bits, Frequency 0, and Frequency 1 set to 1200, but we can play with that later. Leave Differential Encoding checked.

=== Demodulator Tab ===
On the Demodulator tab (which governs decoding audio signals into bits) the options are much the same, save that the Mode selector has an extra option (p3d). Leave everything else the same for now.

=== Packet IO Tab ===
On the Packet IO tab, the network/non-serial side of soundmodem is configured. Pick an IP address, netmask, and broadcast addres for a network interface (hint: stick with RFC 1918 for now). There are two options in the Mode selector, KISS and MKISS. I went with the default (MKISS).

= Theory =
When running the soundmodem utility ('''soundmodem /etc/ax25/default.conf &'''), the daemon configures the sound card to send and receive bitstreams encoded as audio through the jacks in the soundcard. On the network side of the house, it allocates a virtual network interface (sm0) which has a callsign associated with it (relevant for ham radio, not so much for other applications) as well as an IP address, network mask, and broadcast address. The idea is that whatever packets are sent through that network interface will be transparently converted into sound and transmitted using whatever device is connected to the headphone and microphone jacks of the computer. Conversely, any data received by the broadcast device (ham radio, laser, etc) is demodulated into bits, encapsulated into network frames, and made available to the OS.

In theory, it's just like a point-to-point IP link, only instead of ethernet you're using a nebulously defined network technology. You should then be able to do with this network interface what you could do with any other: send and receive traffic, route packets, use IPtables to filter traffic, et cetera.

= Diagnostics, Testing, and Configuration =
Here's where you debug your configuration. It's going to take some flipping back and forth between tabs to get right the first time.

You really should run soundmodemconfig from a terminal, because if you got something wrong (like the audio device) it'll be printed to stderr. It doesn't show up in a window.

The Diagnostics menu only appears when you have a channel (Channel 0) highlighted.

The first option is Scope, for oscilloscope. To get a test signal, click the PTT button (make sure your speakers are turned down!)

The second option is Spectrum, for spectrum analyzer of the signal being send to the sound card. To get a test signal, click the PTT button (again, make sure your speakers are turned down!)

The third option, Modem, dumps the raw bitstreams that your soundcard-emulating-a-modem is sending and receiving. Seeing strings of bits (even when disconnected) means that you have probably configured soundmodem correctly.

I do not know what the AO40-P3D option does. (It's an amateur satellite protocol thingy. We don't need it?)

To save your config file, use the File, Quit option. It'll save it automagically to /etc/ax25/soundmodem.conf.

= So, how is this supposed to work, anyway? =
Assume that you have a laptop running Linux (or Windows if you dare) and soundmodem. Assume that soundmodem is configured correctly. Assume that you have a transceiver - a black box that has a pair of audio jacks (speaker and microphone) on the back, can receive signals, and can broadcast signals.

Further assume that there is a third jack on the black box which plugs into the USB port of a computer. Whenever a signal is sent to that jack, the black box stops receiving and transmits whatever signal it gets through its microphone jack. Alternatively two radios one transmitting only and one receiving only (possibly on different channels) such that there is no need for drivers or a switching mechanism.

You'd connect the speaker jack on the black box into the microphone jack on your laptop. You would then connect the headphone jack of your laptop into the microphone jack of the black box. Then plug the push-to-talk USB jack of the black box into a USB port on your laptop.

Whenever a packet (say an ICMP4 echo request) is transmitted to the IP address of device sm0 on your laptop, it is converted by the soundmodem daemon into modulated sound which goes out through the headphone jack to the black box. The push-to-talk circuit engages and the black box stops receiving and goes into transmit mode. The black box receives that modulated static and broadcasts it. When the broadcast is done the PTT disengages and the black box goes back into receive mode. Conversely, whenever the black box picks up a signal it converts it into modulated static, which then goes out through its speaker jack into the microphone jack of your laptop. After the signal hits the mic jack, the soundmodem daemon demodulates the static into bits, packages them into an IP packet, and drops it into the networking subsystem of the kernel.

By using soundmodem we'll be setting up a virtual AX.25 network interface that, insofar as we're concerned, acts just like an ethernet interface. We can use ifconfig, route, and ip to configure it, IPtables to filter traffic, and /proc/net/ipv4/* to tweak it (and set up packet forwarding).

= Other resources =
*[http://www.febo.com/packet/layer-one/transmit.html Setting your TNC's audio drive level] (In other words, fix your volume!)
*[http://www.qbjnet.com/packet.html#soundmodem Using soundmodem with AX.25]
**Are we really going to bother with AX.25?
***AX.25 is used to transport TCP/IP over not-Ethernet. It doesn't look that difficult to configure.
***What about using PPP?
**Has a few things about building PTT circuits.
**Has some notes on how to tune your laptop's sound levels for optimal operation.
*[https://wiki.archlinux.org/index.php/Amateur_Radio Amateur radio nodes] in the [https://wiki.archlinux.org/ Arch Linux wiki]