Using RaspBerry GPIO Serial port ttyAMA0

STEP 1 – Disable Console

You can use this simple tool: RpiSerialConsole (https://github.com/lurch/rpi-serial-console)

sudo wget https://raw.github.com/lurch/rpi-serial-console/master/rpi-serial-console -O /usr/bin/rpi-serial-console && sudo chmod +x /usr/bin/rpi-serial-console 

To display whether the serial console is currently enabled or not, simply run:

rpi-serial-console status

To enable the serial console, simply run:

sudo rpi-serial-console enable 

To disable the serial console, simply run:

sudo rpi-serial-console disable 

STEP 2 – Install and use Minicom

sudo apt-get install minicom

Now run up minicom on the Raspberry Pi using

sudo minicom -b 9600 -o -D /dev/ttyAMA0

STEP 3 – Test your serial port

If you can test your port connect Pin8 to Pin10 and write with your keyboard

STEP 4 – Connect your device

Connect your device to the Raspberry Pi serial port using an appropriate wiring on Pin8 (TXD) and Pin10 (RXD). Setup a connection using the serial port at 9600 baud.