David Griffith wrote:
Michael J. Coslo wrote:
On Apr 14, 2:46 am, "D. Stussy"
wrote:
"David Griffith" wrote in message

...

Does anyone here done something like sending ASCII to a microcontroller
which then emits morse code? I'm tinkering around with old telegraph
sounders.
Yes. I re-wrote the firmware in my Icom repeater, which included the I
D
section too.

Here's a webpage where a fellow has done something similar:

http://www.steampunkworkshop.com/

It's on the right hand side of the page, a link called "telegraph
sounder"

http://www.steampunkworkshop.com/telegraph.shtml

That's one of the first places I looked and where I got the idea.
However, what he did was have a circuit watch the keyboard LEDs. What
I'm trying to do is make something that attaches to an RS232 port. That
way, I can run a three or four wire cable from a server in a back room
to wherever I decide to put my sounder. There are two ways I could do
this. The first is cheap and dirty. It works by energizing the sounder
coils whenever RTS is asserted. That would require special program --
not too tough, but won't be as flexible as in the second approach. The
other is to buffer RS232 in a microcontroller, convert to morse code,
then tap out the message. In effect, this creates a one-way
serial-to-telegraph modem. That second approach is what has me most
interested. Suppose you have a server writing logs to a serial port...
See the sort of bizzare fun that can be had?

Absolutely!

I would think something like this would be fairly easily done in an
Arduino or basicStamp.

The hardware would be near trivial -- get the thing some power, provide
a RS-232 driver, and a open-collector transistor to drive the sounder.
(what kind of voltage/current does a sounder want?)

You'd have plenty of spare output lines (since you only need one to
drive the sounder!) so you could generate a keyed tone on another
output for driving a speaker, useful once you find out why they
dropped sounders like a hot rock once someone invented the BFO(grin)!

--

Doug Smith W9WI
Pleasant View, TN EM66