building a linux-driven digital picture frame, part 1

8/3/2019 Building a Linux-Driven Digital Picture Frame, Part 1

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uilding a Linux-Driven Digital P icture Frame, Part 1ate: Mar 18, 2005 By Seth Fogie.

A picture might be worth 1,000 words, but does that make it worth $1,000? If you want a digital picture frame, you canexpect to pay anywhere between $300 and $2,000. Fortunately, options are available for those who like the idea, but nhe price tag. In this article, Seth Fogie provides a very inexpensive alternative that can give you much the same effect

but for a fraction of the cost. For about $50, you can enjoy your very own Linux-driven digital picture frame.

OTE

edits: The idea for this article came from a presentation at the Lancaster Linux User Group meeting. Thanks to theirmonstration, I was inspired to design and build my own Linux-driven digital picture frame, which then led to this article

...Thanks, LUG!

e digital camera is quickly becoming a household necessity. While a few film diehards are still around, most people haund the convenience and cost savings of the digital image too attractive to ignore. Not only are digital cameras easier te, but you no longer have to worry about bad photos. If you don't like it, delete it! Or, if you have the time and inclinatiou can use photo editing software to manipulate the image to your liking.

ere are many other benefits; however, there's also one major disadvantage. The digital photo is hard to hang on a wat in your wallet. While it's true that you can set up a computer with a slideshow, how many people want to devote an estem to showing off their photography?

ere are electronic devices that can display digital images. In fact, some televisions have built-in Secure Digital/Compaash slots that allow an owner to turn that $2,000 TV into a very expensive picture frame. For those consumers who areoking for something less costly, other dedicated applications range from the 10.4-inch $499 frame to the smaller 3x5-in50 frame. Be careful when buying these products, though; many of these plug-and-play solutions require a subscriptiooad them with new photos.

not a millionaire, nor would I want to spend that much money for something that I know can be built for less. So I deccreate my own digital picture frame for under $50. In addition, I wanted to create not just one, but several of these devd give them to my parents/in-laws. This meant that I not only had to create a cheap digital picture frame (DPF), but als

ake it easy to use, visibly acceptable, and fairly robust.

ost Breakdown

e goal of this project was to create a DPF for less than $50. Meeting this goal was going to be challenging. Since I wader rather extreme financial limitations, I first created an outline of my expected expenditures:

q Laptop: $3040 (including shipping)q Stand/Frame: $58q Extra stuff (paint, screws, etc.): $3.00

tice that this list leaves out one important piece: the operating system. Unfortunately, any Windows-based OS would h
http://www.informit.com/authors/bio.asp?a=9d8cfd3a-8c91-4770-8a21-afbfab729514http://www.informit.com/authors/bio.asp?a=9d8cfd3a-8c91-4770-8a21-afbfab729514


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creased my costs by at least $20 (Windows 95 retail on eBay). This left only one choice: Linux.

e Operating System

ven my limited funds, Linux was the only real option for an operating system. I could have installed DOS or Windows 9m an OEM copy I had lying around, but technically this is illegal. Since these were to be presents for my family, I really

anted to avoid that kind of unethical conduct, although the thought of the BSA busting in on my parents was amusing!

ciding to use Linux was the easy part; the real question was whichLinux. After a few minutes of searching online, I reat the options were almost endless: Red Hat, Slackware, SUSE, Mandrake, and so on. Fortunately, the fact that I was ely going to be using an old laptop helped dry up the pool of candidates.

y first search was for "small Linux." The results were humorous. Damn Small Linux seems to be rather popular; but ags was to be a family gift and I couldn't see myself explaining that one to my in-laws. I next searched for "Linux boot floich proved to be more successful. I choose this search because my laptop most likely would not have a CD-ROM and

erefore would require a floppy-based installation. This landed me at the floppy page of LinuxLinks.com, which lists mor

an 30 versions of Linux that fit on a floppy. While many of them serve a unique purpose, such as a bootable router or dping tool, several stood out. I researched each version for a few minutes, but came to the conclusion that muLinux wa

st option. First, many sites online were devoted this operating system and its uses; second, it seemed to be fairly popu

h little in the way of negative feedback. So, I took a chance and went to the muLinux web site to learn more.

cording to the developer's web site, "muLinux is a minimalistic Linux distribution, suitable for old computers. X11, GCCNC, SSH, Samba, Netscape etc. are supported on additional add-on floppies. It can be installed from DOS/Win9x or Lihout repartitioning." The muin the name represents a millionth unit, or simply stated, is a way to say "very small." Figuows the muLinux boot screen.

gure 1 The muLinux boot screen.

ne of the key requirements for my operating system was that it had to reside on the laptop. In addition, since I was goinplay pictures, I would need an image-processing program and most likely the X Window System with some window

anager. Not familiar with Linux? The X Window System (popularly but incorrectly known as "X windows") gives Linux ao which a window manager can connect and create the windows/graphics most people expect from their computer.

e muLinux web site had lots of information about the packages and components included with the operating system. Ile to review the /usr/bin directory (Linux program list) and found most of the normal executables. In addition, muLinux

cludes numerous add-ons that can be installed from 1.722MB floppy images, as shown in the following table.

bbreviation Product Description

RV Server Extension (Samba, Smail, etc.) Popular services found on Linux

KS Workstation Extension (mutt, ssh, PGP, etc.) Popular client programs
http://www.linuxlinks.com/Distributions/Floppy/http://mulinux.sunsite.dk/http://popup%28%27/content/images/art_fogie_dfp1/elementLinks/fig01.jpg')http://popup%28%27/content/images/art_fogie_dfp1/elementLinks/fig01.jpg')http://popup%28%27/content/images/art_fogie_dfp1/elementLinks/fig01.jpg')http://mulinux.sunsite.dk/http://www.linuxlinks.com/Distributions/Floppy/


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11 X Window system (VGA-16, fvwm95, Afterstep, wm2) All about X

NC VNC (zip, UPX, etc.) Very popular remote-control program

CC GCC reduced (make, nasm, yacc and lex, Fortran, Pascal) Create programs

CL Tcl/Tk (with a lot of demos) Popular program language

EX TeX typesetting system Formatting of text files

ERL Perl language and libc6 support Great for scripts

MU Wine, DosEMU Emulation software

VM Java Virtual Machine (Kaffe compiler, sshd) Support for Java programs

S1 Netscape Part 1 (SVGA XServer) Required for SVGA and GUI browsing

S2 Netscape Part 2 Ditto

I discovered, part of the brilliance of muLinux is that the components of these packages overlap to reduce their size. ample, the VNC package includes an image viewer and the NS1 package includes the files needed for SVGA (good qaphics) output.

ardware

om my initial expenditure list, I knew that my laptop had to cost no more than $40, includingshipping. As a result, mytions were very limited. A cursory look at eBay told me I was going to have problems finding anything over a 100 MHzocessor, much less be able to afford a color LCD screen or a CD-ROM. In addition, shipping costs added anywhere fro20 per order. So I stepped back and thought about what I really needed.

rocessor

suming that my DPF would only have to load an OS and display images, my processing requirements weren't particulmanding. I wanted at least a 486 processor, but according to the muLinux site, even an older 386SX might work.nverting this to actual processor speed means that I would want a 33100 MHz processor, with a higher number beintter.

AM (Memory)

AM was a more significant problem. Most display programs, such as Windows 95 or even the X Window System (Linuxuld require at least 8MB. While it's possible to load a GUI-based OS in less than 4MB of RAM, any graphics would berribly slow and the chance of failure was very high. As a result, I figured that my laptop would need at least 8MB, with


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eference of 16MB or more.

ard Drive

wadays, most people take hard disk space for granted. Unless you're downloading movies or MP3s, the standard80GB is more than most people will use in a life time. However, space wasn't always this abundant. Even as few as ars ago, hard drives had less capacity than the standard CD-ROM (600MB).

y picture viewer would be storing digital images locally on its drive. This requirement meant that I would need at leastveral hundred megabytes of space for storage. As I thought about the footprint of muLinux, in addition to its swap spacncluded that 400MB should be more than enough space. My calculation was based on the assumption that anything o000 pictures would be overkill. Given the fact that the pictures would have to be reduced to 640x480 (standard display der laptops), each image should be no larger than 100KB. Doing the math, 2,000 pics 100KB = 200,000KB (ab0MB). Assuming that each picture was displayed for one minute, it would take over 33 hours just to run through one cy

CD

digital picture frame wouldn't be very successful without a color LCD display. Fortunately, most laptops include at leasme type of color support. The twist is that not all LCDs are the same. Available colors, quality, angle of view, and moreaffected by the LCD type. The following list outlines the terms/LCD types you need to be familiar with when looking fo

PF candidate:

q Active matrix. TFT LCDs use active-matrix technology, which uses 14 transistors to control each pixel on thescreen.

q Passive matrix. Less costly than active-matrix types, this type of screen uses a grid of wires to display colors.q TFT. The most common, but also the most expensive. The term TFTis often used interchangeably with active mq DSTN. This type of passive-matrix screen is relatively cheap to create and is found in low-end laptops. Generall

type of screen supports fewer colors than TFT LCDs.q VGA and SVGA. The video graphics array (VGA) defines the resolution of the display and the number of suppo

colors. VGA typically supports only 16 colors at 640x480, whereas super VGA (SVGA) can support a much largresolution/color pool, as defined by the amount of video memory and screen type.

you can see, selecting a laptop screen is not a simple process. Be sure to check the specifications of the desired laptfore making a purchase. For the most part, 65,536 is more than enough colors for a DPF. In addition, it's important to

at muLinux supports monochrome, VGA, and SVGA output. The inclusion of SVGA drivers with the NS1 package is one key reasons that muLinux attracted my attention. Without it, the images would be stuck at 16 colors.

ccessories

hile the exact visual design was still up in the air, I could expect that I would need some paint, Velcro, and some sort ome. However, before purchasing any of these items, I would need to have the laptop in hand and working.

summary, I was looking for a laptop with at least a 33 MHz processor, 400MB of disk space, 8MB of RAM, and a colorreen. A CD-ROM would be nice, but not necessary. I was once again ready to start looking on eBay for a laptop.

OTE

uLinux is not the only option, of course. The following table lists the specifications from two similar DPFs created byembers of the LUG.


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pecification Keith Zimmerman Jamie Filson

rocessor Pentium 90 Pentium 90

AM 8MB 16MB

S version Slackware Red Hat

ard drive 10GB 5GB

rchasing the DPF

as ready to spend money. However, after looking on eBay for 15 minutes, I started to get a little perturbed. There werndreds of old laptops online and I found many that fit my requirements. The problem was that they all wanted $1520

pping. I was about to give in and cheat on my bottom line when I found the perfect post.

aptop Blowout!!! 4 Dell Latitude XPi P75D PPS"and only 18.50 for shipping! That would mean that each laptop woulare the shipping cost, for a respectable $4.63 each. Now if I could only win the bid.

not often that I get a chance to snipe (as it's called), but in this case I needed the laptops and the price was right. To ong story short, I won the bid at $102.05 with eight seconds to spare and only seven seconds ahead of another sniperher words, I was now the owner of four laptops at $30.14 each...well within my budget.

course, the story doesn't end here. I had failed to notice the small line that stated "AC Adapternot included." So, witore return to eBay, and $62.00 later, I had four complete laptops for a total price of $45.59 each. Still within my budgets didn't leave much room for accessories!

OTE

hen purchasing a laptop on eBay, pay close attention to the small print. Most sales don't include an AC adapter, and mn't include a hard drive. Also, be sure that the laptop is being sold in working condition. Old laptops are often sold for p

w that we've spec'd out the parts and purchased them, the next steps will be to install Linux and assemble the piecesntinue with those steps in part 2.

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building a linux-driven digital picture frame, part 1

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