Duo Digital Frame
James sent this story to me on August 7, 2002. I believe it was one of the first digital picture frame projects on the internet. - Tom
by James Roos
If you own a digital camera, you've no doubt noticed that digital picture frames have hit the market. These frame typically feature a small color LCD screen and display a slide show of your digital images. At this time, there are only three such frames on the market, and each is seriously flawed. Consider the Poloroid/Ceiva frame. This relatively attractive digital frame is selling for around $100. Sounds like a steal, but the frame provides no mechanism for moving your images onto the frame without a subcription to the proprietary Ceiva network. Ultimately, you'd end up paying a pretty penny for a frame that also suffers from a serious technical flaw, it has a passive matrix display. Another thing to consider is the financial stability of both Ceiva and Polaroid. Both are in trouble, and the Ceiva service could be closed down any day, leaving you with a rather expensive paper weight. Perhaps the most popular digital frames are made by DigiFrame. These frames retail for around $300 and feature active matrix displays. Unfortunately, they are hideously ugly (IMHO). The third frame on the market is the equally ugly Sony model that currently retails for $900. Frankly, for that money, I'd rather have an iBook.
Since an attractive and inexpensive digital picture frame has yet to hit the market, I decided to build my own using a PowerBook Duo 280c and the frame of my choosing. Not a new idea, but the 270c and 280c are the ideal platform for a digital picture frame. Consider the following:
- Active matrix display featuring 1000s of colors
- Ultra compact design can easily be mounted into a picture frame
- Relatively small display is the perfect size. Others have mounted 12" laptop displays into picture frames. Frankly, the results are disappointing. These "frame" look more like laptops on a stick. The LCD on the 270c and 280c is about the same size as a 5x7" print. Larger than all of the commercially available digital frames, but not so large as to look goofy.
- Easy to find and inexpensive. 280c's are always up for auction on eBay and regularly sell for less than $100.
Before I describe the process I used to create my digital picture frame, let me caution you: Tearing apart any electronic product and mounting it in a new case is frought with perils. Like a CRT, the LCD display operates and very high voltages and there is risk of injury during the construction process. Furthermore, the resulting product is not UL approved and could pose serious risk of fire. Perform these steps at your own risk.
If you've never seen the 280c before (or if it's been awhile) well, it's small. Really small. Here's a picture of the 280c next to my Compaq Presario 700. As you can see, the Presario laptop dwarfs the 280c. Notice that the 280c has black bars at the top and bottom of the display. The LCD in this laptop is capable of generating a 640x480 display at 256 colors. For thousands of colors, the display size drops down to 640x400 and these black bars appear. You could always use software to modify the 256 color palette to produce a very pleasing image. I decided to run the frame at thousands of colors at the cost of a little resolution. The choice is yours.
The first step is setting up the software. All this work must be completed before you begin dissassembling the laptop because the resulting frame will no longer have a trackball or keyboard. Note that the 280c does not have an ADB port, so you can't use an external keyboard either. I recommend JPEGView, it has a highly configurable slideshow mode. Setup your JPEGView preferences so that it generates a slideshow from a specific folder. You'll want this slide show to begin on startup, so make sure JPEGView is set to start in slideshow mode and drop an alias to JPEGView in the startup folder. Once you've completed the frame, the only way to add photos to the slideshow will be through AppleTalk, so be sure AppleTalk and file sharing are enabled.
Another thing to consider are the power saving options. Obviously, you don't want the display to go black five minutes after the frame starts up. It's probably a good idea to have the hard drive spin down after some very short interval. I recommend that you set a RAM drive and write an AppleScript to copy your images to the RAM drive at startup. This way, the hard drive will only be used when the picture frame is first booted.
Next you'll need a Torx (T-10) screwdriver to unscrew all of the screws on the bottom of the computer. Once you've completed this work, the keyboard should pull right out.
The keyboard is connected to the motherboard in two places. Push back the tabs to release the ribbon cables and remove the keyboard.
The motherboard is further mounted to the case using several screw under the keyboard. Remove the screws and the top of the casing to fully reveal the motherboard and hard drive.
The LCD panel connects to the motherboard via a gold ribbon cable. Gently pull on this connection to free it.
The motherboard is just slightly larger than my 8x10 inch frame.
Remove the two screws (covered by small patched of gray tape) at the bottom of the LCD. Once removed, the LCD casing can be pulled apart. The LCD assembly is a perfect fit for an 8x10" frame. Since I'd decided to operate the frame at 640x400, I used black electrical tape to mask of the black bars on the top and bottom of the LCD to ensure these regions are not visible through the matting. Since the LCD will be turned off when you mount it on the matting, it may be difficult to discern where these black bars are. The electrical tape ensures you'll know exactly where the image appears on the LCD, and where it doesn't.
I used a high temp glue gun to glue the LCD assembly to the back of the matting.
Once the LCD is glued to the matting, you'll need a way to affix the matting to the frame. I placed a plastic keycard inside the grooves that run along the inside edge of the frame and glued them in place. This proved sufficiant to hold to LCD assembly, matting, and glass in place.
The motherboard will be mounted behind the LCD. I decided to retain the original plastic case of the 280c to insulate the motherboard from the back of the LCD. I used a box cutter to score the plastic and create a place to mount the motherboard.
Again, I used the high temp hot glue gun to glue the motherboard assembly to the back of the LCD. At this point, I cut and glued some small balsa wood blocks to provide additional support for the motherboard. The resulting assembly is surprisingly strong.
The hard drive is glued above the memory expansion slot.
The next step was to create an enclosure for the back of the frame. I used some balsa wood to build a small frame for the rear components. I cut holes in the frame for the power cable, LocalTalk cable, and a hole at the top to promote convection. Balsa wood is available at most craft stores (e.g. Michael's, MJDesigns) and is very easy to work with.
I painted the frame with a flat black spray paint and affixed it to the back of the frame. I decided to retain the original frame backing with the tie-shaped flap used to hold the frame up. This piece was glued to the back of the box I created.
The resulting digital picture frame was cheaper than any of those available and matches my taste perfectly.