node morsecmd -s 10 -t 800 -i 'Testing 1 2 3' -o ./morse.wav
--sidetone -t Sets the tone frequency. Default is 800
--wpm -s Sets the speed in wpm. Default is 10
--input -i Sets the input text to convert to morse code
--output -o Sets the output file (must be a .wav file)
You can also pipe and/or redirect from STDIN and to STDOUT with morsecmd.
echo 'Hello world' | morsecmd > hello.wav