FPGA fun
in [Design]
|
Prev: CONTROLLED DEMOLITION INC explosive-charge placement technician Tom ?Sullivan 911 TESTIMONIAL Video
Next: 74LVC4245A alternative with individual direction?
From: Jan Panteltje on 29 Jun 2010 07:05 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.
From: Nico Coesel on 29 Jun 2010 16:39 Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >This article in German describes how to use a cheap (30 Euro) digital >picture frame as 'industrial display', those displays are usually very 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/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. 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(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: Jan Panteltje on 29 Jun 2010 17:36 On a sunny day (Tue, 29 Jun 2010 20:39:39 GMT) it happened nico(a)puntnl.niks (Nico Coesel) wrote in <4c2a58d7.963374859(a)news.planet.nl>: >Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: > >>This article in German describes how to use a cheap (30 Euro) digital >>picture frame as 'industrial display', those displays are usually very expensive. > >pchub.com carries a wide range of second hand displays for little >money. And they do test their stuff before shipping. 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/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. > >And lesser quality due to compression artefacts. 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
From: Paul Keinanen on 30 Jun 2010 02:32 On Tue, 29 Jun 2010 20:39:39 GMT, nico(a)puntnl.niks (Nico Coesel) wrote: >Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >>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. > >And lesser quality due to compression artefacts. Those compression artifacts in broadcast TV are due to trying to insert too many TV-programs into a single 8 MHz multiplex (typically 22 Mbit/s net). In a CCTV application, the whole 8 MHz multiplex could be used for a single stream. A less robust error correction would suffice, increasing the net payload to close to 30 Mbit/s. Of course, the receiver might not be able to handle that high bit rates. The compression artifacts are going to be rare, when sufficient bandwidth is available.
From: Nico Coesel on 30 Jun 2010 11:53
Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >On a sunny day (Tue, 29 Jun 2010 20:39:39 GMT) it happened nico(a)puntnl.niks >(Nico Coesel) wrote in <4c2a58d7.963374859(a)news.planet.nl>: > >>Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >> >>>This article in German describes how to use a cheap (30 Euro) digital >>>picture frame as 'industrial display', those displays are usually very expensive. >> >>pchub.com carries a wide range of second hand displays for little >>money. And they do test their stuff before shipping. > > >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), They have smaller ones. They are at the bottom of the list (sorted alphabetically). >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. 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/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. >> >>And lesser quality due to compression artefacts. > >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. 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(a)nctdevpuntnl (punt=.) -------------------------------------------------------------- |