FPGA fun

 

This article in German describes how to use a cheap (30 Euro) digital
picture frame as 'industrial display', those displays are usually very expensive.
 http://www.heise.de/ct/projekte/machmit/ctlab/wiki/DigitalerBilderrahmen
 http://www.heise.de/foto/artikel/Digitale-Bilderrahmen-zweckentfremdet-1023520.html?view=zoom;zoom=1

As a short translation: the way it is done is disconnect the analog R, G, and B
signals
used with these TFTs, and leave the scanning signals to the display intact.
Then sync the FPGA to the scanning signals.
Fun fun fun, I still may have a display like that laying about :-)


My own idea is now that cheap (100 Euro) portable DVB-T receivers with similar
display are available, will somebody please do the DVB-T modulator in FPGA?
Then changing hardware on these displays in no longer needed, and you have 25
fps.
 

 



expensive.

pchub.com carries a wide range of second hand displays for little
money. And they do test their stuff before shipping.


http://www.heise.de/foto/artikel/Digitale-Bilderrahmen-zweckentfremdet-1023520.html?view=zoom;zoom=1


signals

fps.

And lesser quality due to compression artefacts.  

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

On a sunny day (Tue, 29 Jun 2010 20:39:39 GMT) it happened nico@puntnl.niks


expensive.

Interesting site.
The problem with that is, that after you add shipping costs,
order it, it lands in the NL customs, you have to pay
import duties too, for a 10 inch LCD (the smallest new one I could find on their
site),
that would make about 20 Euro + 20 Euro shipping + import duty + waiting.

I can drive to / order from <you name it conrad.nl bol.com V&D???=> and pick up
a 7 inch for 40 Euro now.



http://www.heise.de/foto/artikel/Digitale-Bilderrahmen-zweckentfremdet-1023520.html?view=zoom;zoom=1


B signals

fps.

I think not.
I have enough experience with jpeg and mpeg compression to know that stills or
almost stills
get no loss in fine details.
I have experimented with that,
What you call 'loss of detail' only happens when things move.
In displaying a meter panel or some waveform it comes out 100 %.
Mpeg2 being just jpeg with interpolated frames, try it with a jpg of
a sine wave waveform with some small font text, and see how incredibly far you
can reduce
quality before it becomes a problem.
You can use 'xv' in Linux to save ever more compressed images of the same
waveform to try.

Looking for DVB-T modulator there exists many cores, and many complete
solutions, but almost nobody gives prices,
and the ones that do ask > 1000 Euro...
I could program one, but hell do I have to program EVERYTHING myself?
And I would have to fork out for the specs...
But I found this:
 http://www.commsonic.com/products/TDvbTModulatorDiagram.htm
It is doable....

Osama

 



expensive.

their site),

They have smaller ones. They are at the bottom of the list (sorted
alphabetically).


a 7 inch for 40 Euro now.

But that probably has a very low resolution. Otherwise I'd like to be
enlightened :-) I may have a hobby project coming up requiring a
640x480 6.1" screen.


http://www.heise.de/foto/artikel/Digitale-Bilderrahmen-zweckentfremdet-1023520.html?view=zoom;zoom=1

B signals

fps.

almost stills

can reduce

I suppose so but having a still picture on a display is not going to
do much good.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

On a sunny day (Wed, 30 Jun 2010 15:53:37 GMT) it happened nico@puntnl.niks


I will look again.



up a 7 inch for 40 Euro now.

OK, anyways, I went over to V&D and got myself an 8 inch Kodak for about 49 .
This one has a touch interface, not on the screen itself, but on the border so
to speak.
I bought it because the quality is absolutely stunning, very bright too, colors
are correct.
The interface is slow, maybe a 4MHz Z80??? hehe.
Tried to open it, removed some screws, but so far I have not been able to open
it, and I do not want to demolish it,
now it is on my desk displaying full earth rising as seen from moon by that
Japanese spacecraft,
Maybe I will hang it on the wall and go for the DVB-T modulator.. have not
decided yet.
Of course the resolution is much less then 680x480, but people are so used
to rotten de-interlaced B quality low bitrate movies played on HD capable sets...
I think this will do for many things.


Well, if you use it for example as a scope, and grab a waveform, then you have a
still picture.
One feature I thought of for the digital scope is to have it beep
every time it skips (loses) a trigger :-) LOL
I mean if the waveform, or whatever you want to display, MOVES, then it is less
sharp anyways,
this is the whole idea of MPEG compression,
moving things need not be so sharp displayed, so that reduces bandwidth, needs
less bitrate.
As somebody already pointed out you can get to max bitrate if you 'own' the
channel.
MPEG2 is really really good above about 6000 kbps.