Serial and network connections

In this book, I'm mainly going to use two different kinds of connections to interact with the embedded kit: the serial console, and an SSH terminal and Ethernet connection.

The serial console, implemented over a USB connection, is mainly used to manage the system from the command line. It's largely used for monitoring the system, and especially for taking control of kernel messages.

An SSH terminal is quite similar to the serial console, even if is not exactly the same (for example, kernel messages do not automatically appear on a Terminal), but it can be used in the same manner as a serial console to give commands and edit files from the command line.

In the chapters, I'm going to use a Terminal on the serial console or over an SSH connection  to give the most of the commands and configuration settings needed to implement all the prototypes explained in this book.

To get access to the serial console from your host PC, you can use the minicon command, as follows:

$ minicom -o -D /dev/ttyUSB0

However, in Chapter 1 , Installing the Development System, these aspects are explained and you should not worry about them. Note also that on some systems, you may need root privileges to get access to the /dev/ttyUSB0 device. In this case, you can fix this issue or by using the sudo command or, better, by properly adding your system's user to the right group by using the following command:

$ sudo adduser $LOGNAME dialout

Then log out and log back in again, and you should be able to access the serial devices without any problem.

To get access to the SSH Terminal, you can use Ethernet connection. It is used mainly to download files from the host PC or the internet and can be established by connecting an Ethernet cable to the embedded kit's Ethernet port, and then configuring the port accordingly to the reader's LAN settings (see all the instructions in Chapter 1 , Installing the Development System).