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Re: amsat-bb] Radio Control via Internet



> 
> I'm also spending some time to figure out how to making control of a
> receiver by LAN.
> My target is to have a server (LINUX) directly connected via serial line to
> receiver, and a client (WIN) to control the device.
> At present I've done some experiments using socket programming + serial
> programming on Linux, and on the other side I use VB5 enviroment.
> For now the control of the receiver is not a problem ( I have tried with a
> RHODE & SCHWARZ ESM500 receiver that is used on my QRL), but I want also
> "pass" the audio from receiver by LAN.
>   THIS IS A REAL PROBLEM HIHI.
> Any ideas by the group ???

I have been controlling my radios here for quite a few years over the
internet.  The system is pretty nice. It runs on a UNIX box (Solaris).
I can control my Icom IC-R7000, my YAESU FT-847, Bearcat 245, and my YAESU
FT-757GX.  The best way to do it is create a program that sets the
frequency and mode from the command line. For example, the program to
control the 847 here is simply called 847freq.  So, if you execute 

847freq 15000

the FT-847 goes to WWV on 15 MHz.

Here is the cool part:  Run a WWW server and put the 847freq program in
your /cgi-bin/ directory, now you can control your radio with a WWW
browser !  I also created a program which grabs the output from WWW servers
from the command line.  The program is called 'ws'.  So, if I am at
work and want to change the frequency of the radio, I don't have to use
the WWW browser if I dont want to, I can just execute

ws http://www.nr0d.ampr.org/cgi-bin/847freq?15000

and it sets the radio frequency !

UNIX works pretty good for all this because you can log into the machines
and change volume settings, etc.  You can also login from across the
internet and hook up to your TNC too then.  I have been logging in during
lunch time and playing around on 10 meter packet lately like this.

I also have some Tcl/Tk programs which call these scripts, so that is 
another GUI interface to the radios.  

For the audio, I have a Linux box running a Real Audio server.  You
connect to that box for the audio.  I don't run this configuration
anymore, but I used to have the left channel of the real audio feed HF,
and the right channel VHF from the R7000.  Then I could listen to
GHFS/SHORTWAVE, etc AND the cops when I was at work !

Some people use Shoutcast (mp3) for the audio, that is ok too, but I don't 
know of a UNIX based encoder.  If you like Windows, that won't matter to you.
I like Real Audio better.  I have seen a 12kbps Shoutcast stream drop audio,
but Real Audio can run quite nicely upto 16kbps over a 56k modem line.

One more thing:  These radios arent connected to serial lines anymore,
but they used to be.  The problem is that you will run out of IRQ's.  I
now have a terminal server with 25 serial ports.  All the radios are
connected to that. The KAM Plus is connected to it too.  All the
devices  have their own IP address.  So, the 847freq program used to
connect to /dev/cua/a and do its thing, now it uses Berkeley sockets to
do the same thing.  It doesn't matter in C, you use an
open("/dev/cua/a") call to get to the serial port and it returns a file
handle, which in turn you use for a write() call.  Well, instead of
using open("/dev/cua/a") to get the file handle, you use a socket(), connect()
sequence which also returns an integer file descriptor.  The modification to
make it use the terminal server  instead of the serial ports was trivial.

I am also working on a Java based program which takes the output of the
Kantronics Kam and displays it in a web browser.  I didn't write that code,
my freind Glenn Valenta did that work.  The main purpose of this was so
my friends could watch marine sitor output from the Kam when I was monitoring
that.

I have alot of other software I have been running and tinkering with over
the years here.  None of it is really production grade yet.  I think I am
the only person that knows how to run most of it, so I can't give you a
turnkey solution to do what I have been doing, but hopefully you can place
your efforts into control via the web, it is the way to go.

-- 
JEFFREY R. COMSTOCK
EMAIL: JRC@BRAINIAC.MN.ORG
CW:    -. .-. ----- -..
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