A few weeks ago I wrote an openBSD client to connect to CWCOM servers and called it irmc.
A new version of the client was implemented using an Atmel microcontroller. I decided to use an arduino board that was gathering dust on my work bench. I was initially planning to use the arduino as a testbed only and build an actual board later, But I usually only have time to do weekend projects and the coding already took me the entire weekend. So I decided to put building a standalone hardware for later or maybe never.
The source is available here http://fernan.bitbucket.org/irmc-avr.tgz. The code is written in C compiled using the avr-gcc tools. Orginally it was a port of the original irmc, but the limited memory of the atmega required a considerable rewrite. In addition to the limitation of the original irmc, here are few things to note.
1. Only 12 presets are programmed, instead being able to connect to an arbitrary frequency/wire.
2. PD6 is a GPIO that generates a ~650Hz square wave tone.
3. Some clock jitter results in 4ms variation in timming was observed.
4. I have it configured to interface to a separate sidetone generator for keying so the key input is expecting a 5V pulse.
5. I did not like the way I implemented the MorseKOB latch function in the original irmc, so I did not add that function into the avr version. (maybe someday)
BUGS?: Probably a few.
The final version was placed into an enclosure. The green LED blinks to indicate that it is connected to the cwcom servers.