I built a Teensy USB MIDI project years ago for interfacing a morse code key to a PC, it works great, but some people just can't figure out MIDI.

It turns out that there is another way to interface a morse code key to a PC over a serial port. It toggles CTS and DSR in one direction and RTS in the other. I've got a working example on my desk using a USB<->Serial converter connecting to a morse code program running in Wine on my Ubuntu laptop. It would be neat if I could extend the morse MIDI interface widget to support the morse Serial interface as a second option.

I've looked through the Teensy USB Serial code but I haven't found any sign of the full set of RS232 control signals. Is there any way to get at these signals in a Teensy implementation of USB Serial?