Disable Serial Port Terminal Shell Output on the Raspbian/Raspberry Pi
By Default Raspberry PI Raspbian OS is using serial port as console terminal port.
To disable that function start raspi-config tool:
Go to “8.Advance Function menu” , then “A8.Serial” and select “No” to disable shell terminal on the serial port.
On the new Raspbian Jessie release as of May 2016 serial port is disabled by default , it has to be enabled in config.txt!
To enable run next command to edit confix.txt:
sudo nano /boot/config.txt
Change enable_uart to 1 or add line if does not exist:
In the case of Rapsberry Pi 3 one more line has to be added to config.txt because serial ports are swapped!
Reboot the Pi after update!