Back in the days when photons hammered latent images into silver bromide grains, the craft of photography produced pieces of paper you passed around or hung on the wall. Photons now boost valence electrons to create latent images on hard drives, but paper images still require tedious fiddling that we usually avoid.
You can, of course, admire images on your monitor and e-mail them to your friends and relations for their monitors. Ordinary folks dislike huddling around a PC and won't deal with the usual hassles just to see the grandkids, so those images return to latency fairly quickly.
All this has created a market for "digital picture frames" that display image files from flash memory on an LCD panel. A hundred bucks gets you a small LCD in a tacky plastic frame with a low-res slide show of a few dozen pictures. Half a kilobuck produces an image large enough to see across the room and maybe a wood frame. The quality and usability leave a bit to be desired, to judge from the reviews.
Seen from a different angle, though, a do-it-yourself picture frame provides an excellent platform for learning embedded systems programming. It's difficult enough to be interesting, easy enough to be approachable, educational enough to be worthwhile, and cheap enough to breeze through the Spouse Approval process. Best of all, anyone can appreciate the end product, even if they don't appreciate the underlying tech.
Here's a guide to the DIY DPF process, with an emphasis on tools and techniques that you'll find useful in other contexts. Indeed, this DPF is a thinly veiled excuse to show how virtualization works out in practice, so keep reading even if you abhor DPFs.
This month, I cover the overall issues and get into the preparations. Next month, I'll show how it all works.