Thursday, August 23, 2012
My workbench tends to reflect the state of my mind: somewhat cluttered (there is a lot going on in there!) I have some trepidation over having any bare-bottomed PCB being electrically powered up on a surface that also potentially has screws, wires, paperclips and other conductive metals capable of shorting out the board. Sometimes I resort to simple stand-offs; but that does not protect from avalanches from above. For the Raspberry PI, I found an elegant solution from ModMyPi: a well-crafted plastic case that snaps together as a fitted shell. It runs about $11 USD. Something as cool as the pi deserves to look good, too!
ModMyPi Store [Link]
My other interests [Link]
Monday, August 20, 2012
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
Broadcom Video Core IV
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!
Raspberry pi Org [Link]
Newark Element 14 Store [Link]
My other interests [Link]