"U-Know-Who" wrote in
:


"Leland C. Scott" wrote in message
...
On Sat, 15 Apr 2006 22:25:02 +0000, Slow Code wrote:

"Leland C. Scott" wrote in
:

On Fri, 14 Apr 2006 16:11:39 +0000, Slow Code wrote:

"Leland C. Scott" wrote in
:

On Wed, 12 Apr 2006 16:43:09 +0000, Slow Code wrote:

"Leland C. Scott" wrote in
:


"Slow Code" wrote in message
ink.net...
"Leland C. Scott" wrote in
:


"Slow Code" wrote in message
nk.net...
"Leland C. Scott" wrote in
:


"Jim Hampton" wrote in message
...
Has gone? Hmmmm ....

Not really

I'm just glad a few folks can get a few posts across with a
bit of sanity -
even if only once in a while

It's been a load of fun reading the wild posts about me. It's
like sitting back with a cold one and watching a dog chase
it's own tail for hours on end because it's too dumb to know
better. From reading the posts the really dumb ones stand out
from the crowd. Better they left their mouths shut rather
than opening it thus relieving all doubt.

Anyway I've had better things to do the last few weeks,
finally got my TI 320C6713 DSP EVM boad with the development
software so I've been busy with another engineer buddy
working on some DSP projects. Nothing like going back to
review all the discrete time system theory, FFT's and
z-transform stuff I learned years ago. It's a lot more
interesting than the silly name calling and baiting to start
a flame war going on in this news group lately and I don't
want to waste my time with such crap either Jim.


That gave me a headache, I got the TAPR 56000 EVM, Put it
together. Tried some 9600 packet, and 400 bps psk telemetry
when A0-40 was still working. I have it collecting dust now,
as soundcard software is easier. Don't even hook up my
MFJ-1278 TNC anymore either.

I wouldn't say that the sound card software approach is
"easier" at least from a design standpoint. From a user's point
of view you're right about the ease of use, you can't beat it.
The main difference between a DSP board as opposed to sound
card software is performance. And that is a two part issue. One
is raw computational performance and the second is power
consumption. The TI 6713 on my EVM gets barely warm while
cranking out 1200 to 1300 MFLOPS. Then take a look at the
monster sized CPU in your PC and it's heat sink. No contest. A
last point DSP chips don't waste transistors on stuff that
isn't needed like virtual memory, privilege levels etc. that
only matters to CPUs running general applications and need to
be protected from other users on the system.

One of the things that the TI EVM development software does for
you is the complex scheduling of the various routines that have
time critical deadlines to meet. If you do the sound card
routine, writing it yourself that is, you have to not only do
the application code but you have to write your own scheduler
routine and maybe with multi-level interrupts you assign to the
different threads running.

Writing code for DSP chips has gotten easier now that most
vendors have "C" compilers you can use. And at least with TI
they have a DSP BIOS that handles the low level hardware crap
so you don't have to using assembly code. Add on hardware often
comes with plug-in modules containing the required low level
code so you don't have to write it yourself. You just call the
low level routines from "C" using the provided function
prototypes in the vendor's "xxx.h" files and the linker finds
the code in the vendor supplied library files.

One of the interesting things I've found out is some hard-core
audiophiles are using some of the DSP EVM boards to do some
custom filter and complex frequency-gain adjustments etc. I've
seen some lively discussions among some of them over which EVM
system is best to use or going a roll-your-own approach is
better. Some of them were looking for doing direct digital to
audio applications, some audio equipment has direct digital
outputs, with noise reduction etc. because they don't like the
limitations of the commercial gear out there.

Thanks for the post. It's refreshing to have an intelligent
exchange of messages compared to the infantile crap some others
are trying to get me to waste time on.

http://focus.ti.com/docs/toolsw/fold...dsk6713.html#t
op TMS320C6713 EVM

http://www.dspguide.com/pdfbook.htm Free for down load a text
book on DSP theory


My EVM came with five thick books. I went through part of the
first one and realized to write my own software for it, it was
going to take some time to learn things. So I mainly used
software written by others.
Why re-invent the wheel. I still don't have a lot of time to
play,
but maybe someday I'll plug it in again and learn a little.

SC

Hey, it's never to late. You stop learning when you're dead in my
view. It sure beats exchanging insults on this news group.

Yup, reusing code written by others is a good idea, why reinvent
the wheel unless you're doing it for self pedagogical reasons. In
fact that's one aim for good software engineering practice; code
reuse. Was that EVM board a stand alone system or was it part of
some kit it was to be used in? I assume you're referring to the
Motorola 56000 DSP chip you mentioned in another post.


Funny talking about DSP in this group. I normally come here to
stir a little when someone says their CB broke. LOL. I know
that's mean.

What the heck, you have to play with the kids some time. 8-))


Mine has the motorola DSP56002EVM. TAPR made a kit to use it in.
You can connect a couple radio's to it. It has status lights on
the front you can program to indicate various states like what you
would see on a regular multi-mode TNC. On the back is a
programming port and a communications port. My soldering iron was
probably only hot for about an hour and a half putting it
together.
It's really quite neat setup, after you load the modem software
you want
you can use it without having to wire every up again, or switch
cables. It's nice to have two computers hooked to it. One to use
as a terminal for what ever you're doing. PSK, Packet, etc, and
the other computer to load the modem software and program it. If
you only have one computer you have to switch back and forth. One
thing I didn't do but wanted to was burn an Eprom with the
different modems on it to switch between modes faster. What I had
to do each time I used it was load what ever software I wanted to
use at the time. There was another way you could load two
different modems in it at the same time but I never did that.

That sounds like a nice kit they put together. They supply any
block diagrams or other documentation explaining how the code
worked?

I'll have to look. I think it was covered in one of the books, by
Motorola but TAPR didn't provide one.

I wouldn't mind looking at it if you find it. I do have an older book
from TI titled "Theory and Implementation of a splitband Modem Using
the TMS32010" if that rings any bells for you.




If you can program yours in a higher language and compile it down
to the EVM, that's a lot better than using an assembler like I got
with mine, though some members of TAPR wrote some apps to make
things easier.

If you look around you may find a compiler released under the
public GNU license agreement that would work for your DSP chip. If
you get the bug again it would be worth the time to look.


Like I said, I'm not doing much with it right now. Time is the
problem. It's easiest to use the soundcard.

I've looked at some of the FFT routines used on some of the
software defined radios being sold. The one I looked at wasn't
documented very well. I wish that people who write code for public
release did a better job at documenting what they did with more
in-line comments and extensive cometary in the header files.


If you develope a new mode, you might have to port it to the PC so
everyone else can use it.

What I'm working on, with another engineer buddy from work, is sort
of a midnight engineering project that's work related but not
necessary for work if you get my meaning. Many companies like to
swipe work related stuff people do and then paten it under the
company's name with no compensation to the employee and that's even
if they did all the work on their own time and at their own
expense. There was a magazine published at one time I've read
called "Midnight Engineering" that covered exactly these sorts of
issues with engineers developing ideas on their own at home. I
don't know if the magazine is still published or not.

There are a number of people in Amsat that
are working with DSP for the satellites. Look around for Phil
Karn, he's a good one to bounce ideas off of, and knows who else
is experimenting.

I've seen Phil's name mentioned often.

Also browse TAPR, I don't know what they're doing DSP
wise these days.

They are in to the new thing; software defined radios. They sell a
kit with a home grown DSP board to use with it. Even the
professional community is in to it big time as well.

I was never a member. I only really got into the EVM
& DSP when you couldn't buy an AEA DSP.

I thought that AEA still made DSP modems for packet. At least
that's what I thought I saw at last years Hamvention. They usually
set up in a hallway between a couple of the larger rooms. The rage
now is using commercial WiFi 802.11b gear for extended range. One
company I checked out on the Internet is selling a 2 watt
bi-directional 2.4 GHz amp. To get one you must supply
documentation to them proving you're a licensed Ham before they'll
ship one out to you. No proof no amp. As long as the WiFi stuff is
operated on the correct channels the frequencies used fall in to
the 2.4 GHz allocation Hams can use so we can legally run much
higher power with gain antennas that ordinary WiFi users can't. And
here's the kicker operating that way, under Part 97, any
interference ordinary users suffer they can't do much about it
since the commercial WiFi stuff is licensed under Part 15.

Regards,
Leland C. Scott
KC8LDO


The AEA unit was the 2232 I think or something like that. I haven't
done wifi but I hear alot of talk about war driving. I have a three
foot dish on the tower that I used on 2.4 ghz when ao-40 was going.

How often did you get on? I was on several times myself but work
really put a damper in to the activities. I live in an apartment so
any time I wanted to get on I had to take the setup out side. The
neighbors thought it looked like something from an episode of the
"X-Files" when they saw it! I have a 40" grill dish for the 2.4 GHz
down link in to an UEK300 down converter, to 2m, from SSB. The up
link was on 70 cm, 50 watts in to an 11 element beam from M-Squared.
If I needed more power I've got two 10 w in 100 w out 70 cm brick
amps I could have used. The rig I use is an FT-847. The few times I
got on it really was fun. The half second delay in the audio does
take some getting use too. I'm waiting for the next one to go up. I
want to do some more sat work.

I downconvert
sigs to two meters. Never tried to see what wifi looked like. If
they had a weatherproof unit minus the antenna, I could plug that
on the helix and point the dish around the neighborhood. It has
tight beamwidth & good gain. LOL, hey, Free broadband. ;-) There's
also wireless internet in the area that operates at 2.4 gig too,

The county here, Oakland Michigan, is setting up a free WiFi county
wide access too. It won't be real fast, something like 128kbps, but
it's better than paying for the same slow crap using a network card
through the cell phone telco's.

it gets down
converted an plugs into a regular cable modem. The company supplies
a grid dish and there is some form of transmitter on it. I always
wondered who made the transmitter and if you could buy one surplus
for experimentation. And then experiment with a little with a cable
modem.

If you have a link for that I would like to read about that kind of
setup.


I haven't seen anything on it. I did a Google search once, but
couldn't find any information on anyone experimenting or hacking it.


I'm not on the Leo's much, but can't wait to try P3E the Germans are
building, and we're building Eagle. Some good satellites coming soon.
:-)

You and me both! I got bummed out when AO-40 quit. That bird had the
potential to be a communication master piece if everything worked. I
waited until it went up before getting the gear to work it. Even as it
was after the accident it was impressive. I've been on UO-14, before it
died, a few times running mobile but those birds aren't really made for
rag-chewing. Plus there always seemed to be some overpowered station
hogging the pass nearly every time. You get a window of what 8 to 10
minutes per pass. With AO-40 you had at least a couple of hours to talk
on SSB without having to chase the bird all over the sky constantly to
stay on target with the antennas like you do with some of the LEO
sat's. Readjusting the antennas by hand anywhere from 15 to 20 minutes
was normally good enough for AO-40. Another high orbit sat is what I
like to see and the one they're building now is what I'm waiting for
too.

Regards,
Leland C. Scott
KC8LDO



You don't have HF privileges.



For the satellites we're talking about, you don't need HF privileges.

" wrote in
oups.com:


You don't have HF privileges.

so what, AO-40 was better than HF in many ways.

my concern over the german bird in that they will over do the
complexity and repate what I suspect (with no real proof) was the cause
of loseing AO-40



That's easy for you to spell.

SC

Slow Code wrote:
" wrote in
oups.com:


You don't have HF privileges.

so what, AO-40 was better than HF in many ways.

my concern over the german bird in that they will over do the
complexity and repate what I suspect (with no real proof) was the cause
of loseing AO-40



That's easy for you to spell.
whatis your problem Mr Slow

SC