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how can i recording my analog data in my digital development board ?

HOLY19

Jul 25, 2012
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hi, i have a development board belongs to altera and called cyclone 2 (some more info - http://www.altera.com/literature/manual/mnl_cycII_dsp_board_ep2c70.pdf)


my question is that
i need to receive analog RGB data from a spectrum with vga adapter (my mission is to recording it)
my teacher told my somehow to convert it to digital.
I don't know with what converter to use that help me to transfer the data into cyclone 2?
i have some inputs in there, it's I/O inputs . there's any suggestion how can i do it? some friend told me to use vga to dvi converter (and use wire up with specific pins RGB that i need in digital and connected it to the I/O connector in the development board)
it sounds a lil bit complicated any other suggestion would help me to make easier solution?
however, I need to put the dvi connector in the wire wrap board how do i do it?


I would be grateful for any help!!!


(p.s i dont speak very well english )
 

CocaCola

Apr 7, 2012
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Why did you start a new thread? It only complicates answering, best to keep everything in on place...

https://www.electronicspoint.com/looking-vga-analog-digital-converter-t250476.html

If your mission is to simply record the video, it's much easier to simply use a video recording device that is designed to record video...

Converting it to DVI (as long as you convert it to DVI-D as DVI supports analog as well) is a good start, as you now have a digital protocol and standard, but how much storage space do you have on the cyclone 2 to store data? You are going to gobble up gigs of data in no time flat, what is the resolution of the VGA signal and how many frames are per second are you going to try and capture? I don't believe you are grasping the amount of data you will need to capture and save to do this...

And yes it's complicated to do, it's a lot of data to deal with, that is why most will just use an over the counter video recorder whos sole and dedicated purpose is to record video...
 
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HOLY19

Jul 25, 2012
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Why did you start a new thread? It only complicates answering, best to keep everything in on place...

https://www.electronicspoint.com/looking-vga-analog-digital-converter-t250476.html

If your mission is to simply record the video, it's much easier to simply use a video recording device that is designed to record video...

Converting it to DVI (as long as you convert it to DVI-D as DVI supports analog as well) is a good start, as you now have a digital protocol and standard, but how much storage space do you have on the cyclone 2 to store data? You are going to gobble up gigs of data in no time flat, what is the resolution of the VGA signal and how many frames are per second are you going to try and capture? I don't believe you are grasping the amount of data you will need to capture and save to do this...

And yes it's complicated to do, it's a lot of data to deal with, that is why most will just use an over the counter video recorder whos sole and dedicated purpose is to record video...

thanks.

but unfortunately i have to use in this development board i mentioned
i write in vhdl for getting the RGB data in bus
 

CocaCola

Apr 7, 2012
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Well if you insist get a VGA to DVI-D converter (they cost a pretty penny) don't confuse this with the little dongles that only pass the VGA analog signal to DVI... Hookup all the DVI output pins to input pins of your boards and process the incoming DVI data and save... It's not going to be easy, the first thing you need to do is wrap your head around the entire DVI serial specification so you can write a code to process the incoming data and save it...
 

GreenGiant

Feb 9, 2012
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thanks.

but unfortunately i have to use in this development board i mentioned
i write in vhdl for getting the RGB data in bus

2 questions...

Do you have an unlimited budget?
Are you familiar with Labview?

if you have a limited budget then I would say youre in for quite a challenge, I don't know of a way to code/record it easily
 

CocaCola

Apr 7, 2012
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if you have a limited budget then I would say youre in for quite a challenge, I don't know of a way to code/record it easily

I agree, I don't believe the OP has a grasp of the complexity and amount of data that needs to be processed, compiled and saved to do what he/she desires... To capture a single 24 bit 640x480 video frame (uncompressed) is about 1MB of data, to capture 30 of these a second is 30MB of data a second, that is quite a bit of data to process and save in one second... 1 minute of captured uncompressed video will be 1.75GB!

You not only need the CPU to process this data combine it into a container you also need to have the bandwidth and storage space to actually save it...

You can reduce the output volume if you use a compression codec, but that puts a huge drain on the CPU, and you still have to deal with the incoming data volume...
 

BobK

Jan 5, 2010
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The cyclone 2 is an FPGA with 68,416 configurable logic cells. It is likely capable of doing the job with configurable logic (not a cpu). It has a 256MByte RAM on the development board, so that would allow, by your calculation, for about 4 minutes of video. Now, whether the OP has the knowledge and expertise to do this is another question.

Bob
 

dahhal

Jul 17, 2012
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hi holly

I have no real experience with VGA, though if I had this project I'd hope to take a moment and break down the problem.
a. The VGA development board connector on the board is designed to output. Can the pins be repurposed internally? will the analogue electronics from the fpga allow you to use the pins as a input? Probably not as you have already discounted this.
b. The board has A/D converter? will the analogue R G B be able to be plugged into the A/D or would it blow up the pins. Easy to check the pins with a scope.
c. assuming b is successful can you create a sampling algorithm and sample the signals of the 3 respective signals.
d. will it be useful to learn VGA first by learning how to use the output function? Output is a much more common use of VGA and more examples and the development board has all the electronics set up for it. So the only varible is the VHDL used to create something that outputs on a screen. The other advantage to this approach is that when you do succeed at sampling a single you will be able to test it by using the output function to output what you record.

Once you tackle some of these issues, and have a few seconds of signals captured then the solution to the other problems may present themselves.
 
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BobK

Jan 5, 2010
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About 8 seconds not 4 minutes... ;)
Oh right, missed the 30 FPS .:eek:

Edited: Of course the OP has never told use how much he wanted to capture, could be a single frame.

Bob
 
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