Some garbage will start appearing in the terminal. Step 1: Log in to the Raspberry Pi over the serial cable and run the Point-to-Point Protocol Daemon: A network connection running over a serial cable can be very useful for copying files onto the Raspberry Pi. This uses the Point-to-point Protocol (PPP). If this is not possible, as is the case for the Raspberry Pi Model A, you can set up a connection over the serial cable. The easiest way to set up a network connection between your Raspberry Pi and another computer is with an Ethernet cable. Network connection with the point-to-point protocol (ppp) Start GtkTerm, select Configuration->Port and enter the values above in the labeled fields.
Built-in (standard) Serial Port: the Linux standard is /dev/ttyS0, /dev/ttyS1, and so on.
If your PC is running Linux, you will need to know the port name of its serial port: The following parameters are needed to connect to the Raspberry Pi console, and apply on both Linux and Windows. When this is done, you will need to set up a terminal emulator program on your PC as described below. You can connect the Raspberry Pi to a PC using a USB-serial cable, or (if it has an RS-232 port) a level-converter circuit - see above for details. NOTE FOR RASPBERRY PI 3: The Raspberry pi 3 has changed things a bit and you might need to add the option enable_uart=1 at the end of /boot/config.txt (see this post by a Pi Engineer) The Debug Buddy ultimate serial port can also be configured for 0/5 V signals. Other circuits for level shifting are shown at RPi_GPIO_Interface_Circuits#Level_Shifters. See this tutorial for an example using a ready-made level shifter module. If you wish to connect to a peripheral which has 0/5 V signals, you should ideally have a circuit to convert between the voltage levels.
See this tutorial for one example on how to build a 3.3 V to RS-232 level converter with a breadboard, a MAX3232CPE IC and five 0.1 ♟ capacitors. If you wish to connect one of these, you need a board or adapter to convert the signal levels. The ports use 0V and 3.3 V logic levels, not 0 & +5V TTL levels or the +/-12 V used by RS-232 serial ports found on some older PCs.
The Broadcom chip at the heart of the Raspberry Pi has low power serial ports with limitations of voltage and protocol compatibility. You will also need to connect the Ground pins of the two devices together.
To connect to another serial device, you connect the 'transmit' of one to the 'receive' of the other, and vice versa. The Raspberry Pi serial port consists of two signals (a 'transmit' signal, TxD and a 'receive' signal RxD) made available on the GPIO header.