This has been an
exciting year for embedded Linux with the introduction of half-a
dozen single-board computers (SBC) under $100 USD. The Raspberry pi
has captured a lot of that attention at $35 for a 'deluxe' model and
$25 for the base one. I pre-ordered the deluxe pi in April; and after
some manufacturing delays, finally got my hands on it in July. This
SBC costs less than all of the .net micro-controllers I have
purchased (Domino, Panda II, Spider) and has more capability. First
and foremost, it has a Linux operating system (which I downloaded
from www.raspberrypi.org
and burned an image onto an SD card). The SD card functions as a
solid-state hard drive.
The basic specs:
Arm 6 processor
700MHz
256MB RAM
Broadcom Video Core IV
3.5W
There are several
distributions of Linux that have been optimized for the pi; I chose
'Wheezy', which is Debian. Each distribution may have its own default
user name and password (pi, raspberry for Wheezy), which would be
information found on the distribution's download page.
A micro USB connection
powers the SBC. I have a KVM (keyboard, mouse, monitor) switch on my
work bench, which I use to test computers, so I simply plugged in the
VGA cable through a VGA-to-HDMI adapter to the pi, as well as the USB
cables from the switch for the keyboard and mouse. I also hooked up a
Ethernet cable from my router. Upon powering up the unit, typical
Linux boot-up text scrolled down the screen until it asked for the
aforementioned user name and PW. Then a prompt appeared saying enter
"startx" for GUI. This brought up a white screen with a big
raspberry. Clicking on the bottom left tool bar’s icon of the world
brought up the Internet. This process took a minute or two, but
consider that this is a small processor and there is no cooling fan:
it won't replace your desktop nor laptop; but it will serve as a
wonderful embedded computer for a multitude of applications. I am
thinking Raspberry pi mini Web servers for telemetry.
I made a dreadful mistake
that I should warn readers about, that corrupted the pi's file
system. I pulled the power plug without properly shutting down Linux.
The Raspberry pi would not reboot! I had to re-format my SD card, and
re-burn the Wheezy image due to this carelessness. The proper way to
shut down is to log off of the GUI, and in the command line text
enter “sudo shutdown -h now” (-r is for reboot, FYI).
What I would really like
to see developed for this (and all Linux SBCs) is a good touch-screen
display, like found on a tablet computer (like Android has mastered;
but for 'ordinary' Linux). That would ring my bell!
Newark Element 14 Store
[Link]
