additionally to the commands I wrote above here is what I am using(in red) from my SSH login but I still can't 'echo':
root@DD-WRT:~# stty -F /dev/tts/0 raw
root@DD-WRT:~# stty -F /dev/tts/0 -echo -echoe -echok
root@DD-WRT:~# stty -F /dev/tts/0
and I get:
speed 115200 baud; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = ;
eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-brkint -icrnl -imaxbel
-opost
-isig -icanon -echo -echoe -echok
and then:
root@DD-WRT:~# echo "Here I am" > /dev/tts/0 115200
I get nothing on the arduino serial monitor