Multimode Digital Modem

For some time, I've had an idea rolling around my brain. As an amateur radio operator who was never able to "get" Morse code, I've pondered a number of ways I could create a "Morse Code Modem." In effect, Morse code was the first digital radio communications. Morse code generators have been around and cheap for decades. Decoding has been the harder part, but isn't that the fun part about Arduino/Propeller and their ilk?

I followed a rabbit hole and found the Morseduino created by Budd Churchward, WB7FHC. This re-sparked my imagination, and immediately answered a couple of my big questions. Budd was kind enough to answer my questions about his creation, and he also introduced me to the Universal Digital Radio Controller, which looks pretty interesting as well.

I haven't stepped into the weeds, but have started to lay out the project:

• Keep it inexpensive enough to roll around in a go-bag.
• Minimalize the interfaces. Include an LCD to keep it simple.
• "Idiot proof" it. If it is to be useful in an emergency, it needs to accommodate the fact that no one thinks as clearly when stressed as they do when they're relaxed and playing.
• A PS2 keyboard interface makes it fast to enter information, but does add a part that's larger than the project itself. USB keyboards are more ubiquitous, but harder to interface with...Considering all options.
• Easy connections to Kenwood, Baofeng, Icom, Yaesu, etc. HTs, preferrably using PTT rather than VOX to control transmit.

Main functions:

• Morse code encode and decode. Adapt to the variability of Morse in the wild as much as possible, and as automatically as possible and reliable.
• GPS NMEA interpreter
• APRS encode, transmit, receive, decode
• PSK31 digital modem for raw text transmission and terminal connection

I'm considering Arduino or Propeller as the platform. I'm not too keen on using RasPi, even though all the capabilities may be easier to implement on it. It takes longer to boot than I prefer for this and it needs to be gracefully shut down to protect the SD card and OS image, which also takes longer than I prefer. When it comes to a project I prefer a robust end result over easy and slapped together.