David Griffith wrote:
I suppose the next thing to do is look for a good simulator that runs on
Linux.

The Arduino development environment is, if I recall properly, written
in Java & should run on Linux. Don't know about a simulator.

The power requirements of sounders depend on the ohm ratings of the
coils, which is usually stamped somewhere on the sounder. The lower the
ohms, the lower the voltage requirements. Some modern things need to be
done like adding more resistance so it won't be too sluggish. Also a
pair of zeners back-to-back is recommended to prevent something (I
forget what).

Voltage spikes, which could kill the driver. I don't really have a
handle on the magnitude of the current involved in running a sounder,
but I think you'd almost certainly want some kind of driver stage (a
transistor or two, depending on the current requirements) between the
microcontroller and the sounder. Spike protection would be part of
that circuit.

Another thing I'll need to use a few lines for would be some means of
varying the output speed. Yes, an alternate output could ride along for
free. Perhaps also a relay to go to the key input of a radio.

Arduino has analog inputs which could be connected to a potentiometer
for varying the Morse speed.

--

Doug Smith W9WI
Pleasant View, TN EM66