So, I've picked a project. For christmas I'm goign to build a Digital Photo frame out of an old Dell Latitude CPi 300Mhz laptop that' been living somewhere in the loft ! It seems from my friend Google that several otther people have also tried this, so it can't be completely useless.

From this; , to this; !

There are 5 more parts to this story (at the moment) so read on;

Part 2: Base O/S

Part 3: Configure the Software

Part 4: Infra-Red Control

Part 5: Cron, what a tool !

Part 6: We can rebuild it...

(Update) Part 7: We can Re-Rebuild it, better than ever !

(google sketch up model, assembled and exploded !)

Install the O/S Xubuntu 7.10 (Gutsy Gibbon)

I started with a Dell Latitude Cpi, which was hanging around.  This is quite a nice little laptop with the following specs;

• Pentium II 300Mhz
• 256MB Ram
• 1024x768 LCD Display (@24bits, see later)
• 6GB HDD

This should be plenty for a digital photo frame.  For O/S I chose Xubuntu for several reasons

• Whilst other projects had used Windows, I knew that Windows would run slowly on this laptop, and would be had to configure headlessly    
  
• Other projects had used Damn Small Linux, which I looked at, but wasn't quite up to my desires   
  
• I was already using Kubuntu on my normal laptop (Compaq Armada M300), so the smaller brother Xubuntu seemed ideal.

So I downloaded and burned a n Alternative Install CD for Xubuntu 7.10 (because my laptop didn't really have the memory for a Live CD installation, I went text only  Old School !).  This installed fine with a few minor issues;The graphics adaptor in the Latitude is a NeoMagic MagicGraph.. This was recognised by Xubuntu, but configured the display as 800x600 @ 24 bits, it took me a while to work out, but by changing the colour depth to 16bit in my xorg.conf I got the display to 1024x768. 

Whilst I was at it, I did a few other things to the base O/S;

I installed ndiswrapper (actually I compiled it from source, because something happened when I compiled LIRC from source that stopped the ndiswrapper from the repositery from working ) and configured it with a Netgear WG511 PCMCIA wireless card

I installed Wicd to handle WPA security for my home network

I disabled everything I wouldnt need, like printing

I installed Samba, and configured it to share out the Share partition which would hold my pictures. That way anyone in the family can add pictures to the frame
I configured laptop-mode so the hard drive only spins up every ten minutes or so
I set the drives with the noatime option in /etc/fstab to reduce hard disk writes as much as possible.

I set the desktop to no image, black colour. I removed the taskbar and made the menubar smaller and autohide

Next I started to inswtall and configure the various bits of software I needed.

X11vnc,

A VNC server for the current X11 session, roughly according to this post here.

Slideshow

For the slideshow I used feh.  This is a great command line driven image viewer, and provided all the functionality I need.  I can use it to;

• Start the standard slide show, with all the pictures changing every 300 seconds (5 mins)
• Show a collage of pictures assembled randomly on screen
• Show the pictures from a removable drive that's been inserted. 

There are several scripts to start various styles of slide show, all listed here,most are adapted from those listed by drware  here ; 

Clock

I also wanted to be able to show a clock full screen on the display.  I couldn't find a perfect solution, xdaliclock was about the closest I could come up with.  Then I found sunclock, which isn't perfect either, but does look a bit interesting. The clock is started with the start_clock.sh script 

Miscallaneous Software

I also installed unclutter to hide the mouse, and autocutsel to keep the clipboard synchronised between my PC and a vnc client, although it doesn't work ! I use osdsh and osdctl to display messages on screen much like the TV on screen display. I also wrote scripts to turn the display on and off, and to toggle between the two using the remote; 

About half way through the project, I decided that the family would want some control, and using putty or a VNC client wasn't really suitable, after some googling I found the LIRC project which seemed ideal.

The LIRC project is designed to interface with several different kinds of Infra Red receivers and transmitters, like USB or Serial ones which actually decode the IR signal and home made Serial receivers which cheat by toggling the RTS signal line of the serial port. I decided to build one of these.

For this I first built the standard serial port IR receiver from the LIRC website, however, whilst this worked on my Armada laptop, the Latitude didn't put out enough voltage on the Serial port (only about +3V), so I built the more complicated RS232 compliant one. I also used a low voltage drop regulator, which was unfortunately only available as a SMB device, which isn't easy to attach to strip board ! Here's my schematic (I'll try to put some eagle schematics in here at some point, if I ever ressurect my Linux system).

Here's some pictures of the completed board. I built it on strip board, and if you do the same, please, a) make it a bit smaller, b) learn to solder better than I can.

The end result isn't pretty, but it works, which is all I need really. I am tempted to go way off the deep end of geekiness, and try iron on transfer PCB etching, but I'll leave that for another day... I then configured Lirc, Heres my .lircrc file (which wont make a great deal of sense without the other bits of software)

I set cron up to do three jobs;

• Restart the slide show every six hours or so to pick up new images
• Turn the display off in the evening
• Turn the display back on in the morning.

First job, Rip the laptop apart

This part was Fun !  See images below..  No, seriously, This took a while.  I disassembled the case, and removed the LCD from the motherboard.  I kept the motherboard without keyboard or trackpad and the LCD along with the metal screen on the back of the LCD.

Rebuild the laptop

I used a 16x10 frame from Homebase.  This frame has plastic sides which I thought would be great, but it turned out they flex too much and were hard to fix things to, next time, I'll try for an all wooden frame I bought some hardboard and cut a piece to fit inside the frame, I then marked where the screen would go and cut a hole.  I then carved out where the mounting lugs of the frame met the hardboard so the screen sat practically flush with the front of the hardboard.  It was then epoxied in (araldite).

After this was done I masked off the screen and connector and sprayed the whole thing matt black. I then used some offcuts of hardboard to fit a panel behind the screen with a small gap. I then mounted the motherboard to this (more epoxy).  I then attached the frame from a smaller picture frame over the mainboard, aften cutting some slots for the power, pcmcia, video, PS/ and USB connectors.

For the mount (or matt ?) I tried to cut one myself, but it took two hours, looked awful (the second one had blood on...).  I then went into Alnwick and tried the Alnwick Picture Shop, where the nice lady cut me a mount the perfect size in about ten minutes (after working out what I was trying to do), it only cost a pound as well !

I could then assemble the frame, glass, matt and hardboard containing screen and motherboard.  I glued the hardboard into the frame with a bead of bathroom silicone sealant (in case I ever have to get it out again). I epoxied two wire hooks onto the back of the frame at roughly 45 degrees, so I can add some picture wire and hang this on two hooks, its not actually that heavy.

I rewired the laptop power supply cable onto a piece of White Cat 5 (I know, 24AWG Cat 5 can't take the current, well I used 4 conductors for +ve and four conductors for Gnd, so it should be fine !) I also fitted a black push button into the smaller frame and soldered the wires directly to the laptop motherboard for a power switch.

Test and debug

When I turned it on. Eureka ! It worked first time.  Although it does have a slightly annoying habit of not starting / dying every so often if its been moved.  Its because the processor board comes loose, because its got three screws in it, none of which are in the corner where the connector is !  Its a known design flaw with the Cpi, and mine doesnt have the small metal clamp they used to fix it ! Well see how the family like it at Christmas.

Well, they loved it !

But there were a few, teeny tiny problems;

It can be quite loud, due to a) the hard drive whirring up every six minutes and b) the fan whirring up every two.

It wasn't particularly stable on the wall.

It wasn't angled enough on the wall, so only tall people could see the image, due to the LCD sweet spot viewing angle.

Read on to find out how these were solved ....