Making RGB LED display from VGA port

[Gola4u]

Hello friends, I would like to make a simple RGB LED display panel and drive it with the output of the VGA port on my pc so that I can display information on the pc screen onto the LED display panel. I've just learned the pin definitions of the relevant vga port:
Pin 1: Red video data
Pin 2: Green video data
Pin 3: Blue video data
Pins 6,7,8: Red, Green and Blue groundings
Pin 13: Horizontal sync
Pin 14: Vertical sync
My problem is how to drive the 307,200 (640×480) pixels with the single RGB LEDs from the vga port and combining it with the vertical and horizontal syncs. I need help on relevant circuits,ICs (registers, multiplexers, encoders etc...)
Data output of the VGA port are analogue signals.
Thank you.

 

[panic mode]

what did you get so far?
did you figure out power consumption? how about price for all the LEDs?
do you know how much memory is needed to hold 640x480 image in RGB format?

 

[Gola4u]

thanks for your response. At this time, power consumption, cost of LEDs and memory happen to be a secondary matter to me. All I need now is help on the relevant
circuits,ICs
Thanks

 

[panic mode]

awesome, then it's settled, just get Stratix V GX 5SGXEA7N2F45C2N development board. better yet, get few of them, to save on shipping. we can think about those other irrelevant pesky things later on

now seriously, have you any idea what you need to get something like this to work? what is your comfort level and what is the largest project you did on your own?

 

[Gola4u]

thanks so much,
I just checked on the features of Stratix V GX 5SGXEA7N2F45C2N development board and the hardware architecture seems a bit convoluted. I would like to do it with simple ICs(opamps, shift registers, multiplexers etc...), transistors and passive components without any programming. This is my first largest project.
Many thanks

 

[Nigel Goodwin]

thanks so much,
I just checked on the features of Stratix V GX 5SGXEA7N2F45C2N development board and the hardware architecture seems a bit convoluted. I would like to do it with simple ICs(opamps, shift registers, multiplexers etc...), transistors and passive components without any programming. This is my first largest project.
Many thanks

Perhaps you should try something a little more manageable for your first 'large' project? - it's going to be VERY, VERY expensive to do, and VERY, VERY complicated. It certainly won't be "simple IC's".

Essentially there are two main parts:

1) Digitising the incoming three signals (RGB) and storing them in a block of memory in the correct synchronous fashion.

2) Reading the memory back out and displaying it on a huge array of LED's.

I take it you are aware that 300,000+ RGB LED's are going to cost tens of thousands of dollars?.

 

[Gola4u]

thanks for your advice

 

[panic mode]

At this time, power consumption, cost of LEDs and memory happen to be a secondary matter to me.

you must start by estimating cost and other key parameters. otherwise you will never get anything done. even very simple math can help provide much
clearer picture.

for example using cheapest ones from Digikey, LEDs would cost $40000.
https://www.digikey.com/product-detail/en/LTST-C19FD1WT/160-2022-2-ND/3198709

according to datasheet, they consume 3x80mW=240mW
0.240W*307200 = 73728W = 74 kW when all leds are on (displaying white screen).
i bet you did not know this - because you can't multiply... ;-)
do you know what it takes to turn on/off 74kW?

to store single RGB frame we need 640x480x3=921600 byte or close to one megabyte. preferably one would use double of that memory so one can compute one frame while other is being displayed then swap them. that way output can be flicker free. obviously this alone eliminates many products on the market. PIC10F is clearly not going to cut it...

then you need to digitize 3 channels (R, G, B). if you are doing real time update, then you need frame rate of say 30fps, you need mre than or at least 640*480*30fps=9216000 samples every second on each of the channels (27648000 8-bit samples per second or 27megabyte per second). this tells you how much bandwidth you need to not skip any pixels.

 

[Gola4u]

thanks, you're my geek.
The minimum resolution for a standard VGA display is 640X480 and it seems this is not realistic at this level of my project. Perhaps reducing the resolution will reduce cost, power and complexity of the project for now.
Thanks again for your insight .
Any other ideas are welcome

 

[Nigel Goodwin]

thanks, you're my geek.
The minimum resolution for a standard VGA display is 640X480 and it seems this is not realistic at this level of my project. Perhaps reducing the resolution will reduce cost, power and complexity of the project for now.
Thanks again for your insight .
Any other ideas are welcome

Best idea would be to buy one - you're not going to approach the 'low' cost of a commercial unit by building it yourself.

What exactly are you trying to do anyway?, and why?.

 

[Gola4u]

well, this will be very nice on the walls in my room. I just want to have total control over a personalised and bigger screen. It will be very fancy to have a bigger-than-usual commercial screen on the wall .Though minimum veiwing distance will cause pixelation, this is not a big concern.
Now that sounds a bit like a fantasy but as an electronics hobbyist, i must be able to do that on my own within reasonable cost in time, money and mental effort.
Thanks anyway for asking.

 

[panic mode]

thanks so much,
I just checked on the features of Stratix V GX 5SGXEA7N2F45C2N development board and the hardware architecture seems a bit convoluted.

i just mentioned stratix to scare you away
not sure if you saw how much it costs. but this is one pricey baby,
there are FPGAs that should do the job just fine for far less money
but if you didn't program one before this would still be tough one to use.

regardless, price of LEDs alone kills this, this is why i asked this in the first question.
now if you like some attention grabber to make silly display of reasonable size,
you can try so called propeller clocks.

once you find source of cheap LEDs, maybe you can try 3D display too
https://www.youtube.com/watch?v=Qk_03gXvf90

 

[Brevor]

for example using cheapest ones from Digikey, LEDs would cost $40000.

At over 300,000 led's he should get a quantity discount.

 

[Menticol]

First the good news: You don't need 300.000 independent units, as you can see on the following video with "only" 30 x 30 blocks you can build a simple meaningful image.

https://www.youtube.com/watch?v=a51fL61t8CE

Bad news: 900 "blocks" is still a huge number, and any gal in your room will not be able to see anything unless she's seating at some meters away from your creation. That means outside the room.

Even worse news: As a female friend told me, this type of endeavors cross the line between "Oh god you are Tony Stark" scale and reach the "Dude, you have nothing better else to do". I know you aren't asking my opinion but please listen to her's.

Solution There are much better things to build: Your own PWM dimmable lights, your own Minibar, and **a must*** a really good stereo amp (don't forget the remote control). Now if you want to impress not only the girls but all the people at ETO you can make your own DIY Jacuzzi

Meeh, I have a feeling that you are going to stick with the LEDS idea after all

 

[Gab3Ru55]

Lets see, I would recommend checking ebay
**broken link removed** 1000 through hole
**broken link removed** 1000 SMT
The SMT are 50 bucks for 1000 and 150 for through hole, but that is just for LEDs. Keep in mind that this is going to cost a lot for control electronics, use massive amounts of power and get pretty hot. Good luck!
You're off the edge of the map, matey. Here there be monsters!"

 

[Gola4u]

thanks you all, folks. I'm already considering switching to fpga for my project