1. Check your /dev/ttyS0 or /dev/ttyS1

For example, assuming that you are using /dev/ttyS1 do:

> stty -F /dev/ttyS1

speed 9600 baud; line = 0;
min = 0; time = 10;
-brkint -icrnl -imaxbel
-opost -onlcr
-isig -icanon -iexten -echo

if this setting is not correct then do:

> stty -F /dev/ttyS1 -icrnl -opost -onlcr -isig -icanon -iexten -echo

2. run

> onoff 1
> gohome
> onoff 1