View Full Version : Digital Picture Frame
01-10-2008, 09:01 PM
Hi to all,
I want to build a digital picture frame, with a 19" LCD monitor.
I would rather have an embbed design, in order to save space, power·and complexity.
The Design would eventualy work like this,
Get a JPG Picture from a USB Pendrive.
Decode it and insert a OSD time stamp
Put on the screen at 1280x1024 resolution.
wait x secs
Is the propeller ther right processor to make this?
I'm used to work with PIC and Tibbo processors, but they are no use to this project has they require some more horsepower.
So i'me looking into several options but i really do like the Propeller design.
Post Edited (Wolftec) : 1/10/2008 3:03:40 PM GMT
The short answer is "no." Forget it. Wait for the Prop II. Not enough RAM in a Prop to display a tse-tse fly at 1 pixel per mm. Yah-de-yah-de-yah.
The long answer is "yes..." with the Prop anything is possible.
In terms of display... you are going to need a display that you can control with a serial line... see 4D systems for a good example. They don't have a 19" display yet, but by the time you have your thumb drive working, it is entirely possible.
In terms of storing your images... if you change your spec to a 2Gig SD card, it is a relative no brainer.
I would suggest prototyping your system with a 4D Systems: uoled-96, which has a Prop and an uSD card built-in. If you like what you see, it is just a matter of taste as to how you do your final implementation. And the best part is that the entire prototype will cost you less than $100.
AND this is a great starter project... you can hack the whole thing, without knowing much about the innards.
01-10-2008, 09:42 PM
As Rich says: almost anything's possible with the Propeller chip - we're constantly surprised here!
To your specific requirements:
1. I think resolution and colour depth are going to be the spoilers. To my knowledge the highest resolution achieved so far is 512x384 - though I do seem to remember a flurry of posts a while ago that talked of higher resolutions. 1024x768 (See http://forums.parallax.com/showthread.php?p=615350)
2. To i/f with a thumb drive, you'll need to either roll your own i/f - using something like one of the FTDI chips - or use a pre-build device; I think there are several serial to USB drive products on the market, and I know Mike Green's been successful with one from (I think) GHI Electronics?
3. Not sure how you're going to achieve the OSD timestamp (I presume that's to display the *current* date/time?), but Bean of Hitt Consulting has a very good Propeller-based OSD (which I think is available at Sparkfun.com)
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
BTW: I type as I'm thinking, so please don't take any offense at my writing style http://forums.parallax.com/images/smilies/smile.gif
Post Edited (simonl) : 1/10/2008 3:26:05 PM GMT
Not to rain on the parade, but wouldn't it be easier to hack something existing instead of build from scratch? You could take the SanDisk picture viewer (~$50) and maybe hack that with a 19" LCD monitor that accepts svideo/rca. I've only worked with the Propeller a short time but I think your requirements might be out of scope with it's capabilities. It's an awesome chip but still just a little 32K micro-controller not a PC in a chip. Plus if it did have the specs, you'd still be writing a lot of code (USB host, JPG decoder, etc.).
01-11-2008, 06:46 PM
I was looking into the vinculum chip for the USB part, and then use 3 dac's for the vga conversion, i would need about 16 bits color depth for any good picture.
But this project would take much more time than i predicted, so for now i'll be loking into the pico-ITX board or a FPGA solution.
A pity i would really like a good excuse to start working with the propeller chip.
But i will buy the 4dsystems uOLED-96 to at least give it a go, and to look for use in other projects.