What will you display on?

wrote in message
oups.com...

nana wrote:
But Dave, the soundcard is doing that already!

Yes, indeed it is. But I wouldn't be looking to transmit via a PIC if
I could take a PC along. I'm looking for a PIC-based solution in order
to make it flight-weight.

Dave

My PC will be the receive station.

nana wrote:
What will you display on?

wrote in message
oups.com...

nana wrote:
But Dave, the soundcard is doing that already!

Yes, indeed it is. But I wouldn't be looking to transmit via a PIC
if
I could take a PC along. I'm looking for a PIC-based solution in
order
to make it flight-weight.

Dave

But, if you are displaying it on a PC, won't the sound card be inside it?


wrote in message
oups.com...
My PC will be the receive station.

nana wrote:
What will you display on?

wrote in message
oups.com...

nana wrote:
But Dave, the soundcard is doing that already!

Yes, indeed it is. But I wouldn't be looking to transmit via a PIC
if
I could take a PC along. I'm looking for a PIC-based solution in
order
to make it flight-weight.

Dave

Yes, RECEIVING with the PC. Transmitting via a PIC. The PIC will be
airborne. My PC will not.

nana wrote:
But, if you are displaying it on a PC, won't the sound card be inside
it?

Finally, Dave is beginning to give us the complete story.

Now, Are you thinking of generating audio tones using the pic in order
to transmit AFSK, audio frequency shift keying? This will basically be
filtered and sent to the microphone input of a transmitter. Or are you
going to use the pic to control a tone generator? What you use as a
transmitter has a lot to do with how complex the PIC program will be an
which PIC you will use.

Several years ago my company hired an engineer to develop a fax/modem
phone line switch using a 16 bit PIC. I don't remember the number.
Anyway, the circuit he designed and the software the programmer
developed watched for the phone ring tones and for the tones sent by
fax machines. It also generated the ring tones to ring the telephone on
the line it had selected. Just as with your project, it never had to do
all at the same time, although,I think the timer generating the tone
could continue until the PIC turned it off.

Have you looked at all the data sheets and sample programs available
for the PIC from the manufacturer? It's been a long time since I looked
there, but I think there were sme good examples of what you want to do.
Paul, KD7HB

nana wrote:
But Dave, the soundcard is doing that already!

Most Ham RTTY is in Baudot (Paul, take note), I've never seen any ASCII on
air although it was experimented with when machines became available. The
actual code is called Murray Code. Baudot is a bit of a misnomer as it
really refers to timing.

W1AW sends bulletins in 110 baud ASCII.

http://www.arrl.org/w1aw.html

--
Jim Pennino

Remove -spam-sux to reply.

W1AW sends bulletins in 110 baud ASCII.

http://www.arrl.org/w1aw.html

--
Jim Pennino

Well, they'd be about the only ones!

Nana

wrote:
Finally, Dave is beginning to give us the complete story.

Hey. :-) In all fairness, I did say "My goal is to program a PIC so
that it can control a FSK circuit and transmit to my PC, which is
receiving with MMTTY or something similar." Although it was several
messages back.

Now, Are you thinking of generating audio tones using the pic in
order
to transmit AFSK, audio frequency shift keying? This will basically
be
filtered and sent to the microphone input of a transmitter. Or are
you
going to use the pic to control a tone generator?

Probably the latter. I'd like to be able to use a standard handheld
with a PTT. I might have the tone generator be an external circuit
outside the handheld... still not sure.

Have you looked at all the data sheets and sample programs available
for the PIC from the manufacturer? It's been a long time since I
looked
there, but I think there were sme good examples of what you want to
do.
Paul, KD7HB

I've checked a couple, but I don't plan on generating the tones with
the PIC... I'd like to take as much processing off the pic as possible.
Thanks for the help!
Dave

nana wrote:
Aaahhhh! Okie Dokie Dave. Little lights started to flicker on. You
sure are
a cryptic devil, aren't you?

So, why not just generate the 5 unit code at CMOS levels then run it
into an
XR2206 tone generator like everyone else? It will save you hours of
heartache. http://www.klm-tech.com/technicothica/xr.html

Wow, nice chip. I like the datasheet on that one so far. That might
be a great option...

Are you attempting to make a beacon, or something for APRS? What is
the
purpose of the one-way acft borne RTTY transmitter?

Mainly temeletry. Most of it would be GPS information, but some would
be temperature and status information.

I ask because there are
pic type units made that take a GPS position, format it to packet
1200bd
APRS and transmit same on VHF. (search APRS)

Is this what you have in mind?

Somewhat, but I was kinda hoping to have a lot of control over what is
sent... and it'd be educational to design my own RTTY generator.

It'd be going on a high altitude balloon. I've launched one in the
past using pre-recorded audio sounds (numbers and the pilot-alphabet),
but it's slow and consumes more battery power. I'd also like to get
more frequent transmissions.
www.geocities.com/achilles03/hab.htm

Thanks for the info!
Dave