Questions tagged [vga]

stands for Video Graphics Array and provides a 640x820 screen resolution.

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72 views

8 bit PC integrated with VGA video card (similar to ben eater project)

I'm thinking about making a project like this one and add a graphics card like that one. Using an EEPROM for the video memory and changing its content setting it in write mode and assigning a value ...
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1answer
70 views

VGA digitizer with FPGA (input, not output)

Producing a VGA signal with an FPGA has been done by so many people it is a common starter project. What I cannot find is information on how to decode a VGA signal with a FPGA for example to capture a ...
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I accidentally bought an HDMI (male) to VGA (male) cable that isn't an adapter or converter of any sort. Does this product have any value? [closed]

I have a laptop with an HDMI port. I have a monitor with a VGA port. I wanted to connect the two. The website I bought this cable from labeled it as an 'adapter' so I assumed it would do the ...
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1answer
51 views

15 pin VGA configuration

I want to connect a 15 pin vga output from a computer to a TV input. However I do not want any data from the TV sent back to the computer. What I mean is that I do NOT want the TV to be a smart ...
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1answer
56 views

Are the Front- and Back-Porches Required to be Black for VGA?

My first question for this project was how to process a fast analog signal in the first place: Digitally-Controlled Analog Processing for VGA Video Signal? This one is about a specific detail of that ...
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14 views

Input Impedance Simulation

I am trying to design a VGA with CMFB, How can I simulate the input impedance in cadence? https://ieeexplore.ieee.org/document/4230874
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4answers
62 views

Do usb and vga controllers consume power if there are not devices connected to them?

Let's consider the following situation. There is a server, for example supermicro, that has 4 USB2 ports, 4 USB3 ports, and 2 VGA ports. At the same time we don't use these ports, I mean there are no ...
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2answers
49 views

Why do LED/OLED HD and UHD displays have “global refresh rates”?

What is the benefit to scanning vs. individually addressing and updating lines or pixels or screen areas? Is there a standard interface to the majority of HD or UHD displays that allows the ...
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1answer
81 views

VGA to Composite conversion cable

I'm not able to obtain an adapter from local markets for vga to composite video output. Found a circuit [VGA to composite circuit. Does it work?] that claims to work. I didn't had a vga cable so I ...
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1answer
55 views

Digitally-Controlled Analog Processing for VGA Video Signal?

A few months ago, I replaced the dead fluorescent backlight of an LCD computer monitor with an 8-bit-per-channel RGB LED strip, and built a controller for it from an AVR microcontroller that talks to ...
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Present two images side by side on the VGA screen from FPGA

Im trying to get a clue how to present two images on the screen using VGA. I using Altera Cyclone 2 DE2 and VGA, I have already working vga sync driver for 640*480 res: ...
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1answer
76 views

How to implement VGA Controller for Changing Background Color in VHDL

I'm a beginner VHDL coder. For just fun, I'm trying to implement the 640x480 @60Hz VGA controller with Basys 2 Spartan-3E FPGA Trainer Board. My goal is to make ...
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4answers
213 views

How can I make a mod for VGA cable to display only grayscale or Black & White?

My computer connects to the monitor using a VGA cable. I want to turn the display grayscale or black & white. I don't want to use any software solutions as I fear it will not be as effective as I ...
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2answers
362 views

Ghosting in VGA signal generation

So, I'm generating a 1280x1024 (native screen resolution) VGA signal using a Lattice HX8K > Yosys, according to these timings, and a PLL of 107.812Mhz of Pixel Frequency. I then pass it through a ...
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2answers
1k views

Is this how a R-2R DAC for VGA should work?

I'm trying to wrap my head around if this is how a R-2R DAC should work. I say should for two reasons: (1) because I think I understand the theory behind the resistor ladder of subsequent voltage-...
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395 views

Schematic for TTGO VGA32 V1.2 by Lilygo

After recieving a couple of these boards to tinker with I have been searching online for some schematic. I have only found the following useful images: Block Diagrams with several pinouts described ...
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2answers
449 views

How I can resolve the problem of conversion (to_integer(unsigned(variable))

I want to solve a problem in VHDL with Quartus II. I made a model of VGA protocol 640/480. When I made the part of displaying I made one two signal in integer. Error (10621): VHDL Use Clause ...
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1answer
292 views

8-bit VGA DAC Design Question

I am being driven up the wall with designing an 8-bit VGA DAC for an embedded application. Everywhere I've researched highlights the necessity for "impedance matching" the 75 ohm termination ...
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1answer
103 views

Video RAM: How to create a shared bus for processor and VGA controller

I have a discrete video controller which reads a image from SRAM. The image should be written by a CPU. So I designed this circuit. I use two display RAM because I want to use double buffering. So ...
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1answer
95 views

Can an incorrect VGA timing kill a modern LCD screen?

I'm going to play with an Artix-7 dev board with a VGA port (Nexys 4 DDR from Digilent) and I'm a beginner at this. Assuming the pinout is correct, is it possible to destroy a (very) cheap modern LCD ...
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1answer
82 views

Looking for a display RAM for my VGA card [closed]

I´m designing a simple 800x600 pixel VGA card, based on this example (but I don´t reduce the image size). I also want to use a display RAM, so a microprocessor can write a new image. For this I need ...
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210 views

Trick monitor into receiving signal [duplicate]

I have the plan to convert a few old LED backlit monitors into false windows. While I theoretically could buy direct LED drivers to power these panels, I'd prefer to keep the existing circuitry, since ...
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2answers
454 views

How to calculate resistor values for a VGA DAC

I have an FPGA and want it to drive a VGA monitor. I want more than 3 bits of color so I need a DAC of some sort. So I want to make a resistor dac. My plan is to have 3 bits per subcolor. So total of ...
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1answer
116 views

Un-moving “static” image from VGA controller

I am reverse-engineering a daughter card which uses a ADV7125KSTZ140 VGA video DAC driven by a FPGA. The FPGA is a Xilinx Spartan 3E programmed by an off-board processor using slave-serial mode, ...
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0answers
105 views

How to convert arcade RGB video (2-5v p-p) to VGA (0-0.7v)?

I'm trying to convert arcade video signals (JAMMA) to VGA specifications. From what I've gathered, arcade video signals aren't standardized. They can range from 0v-2v or 0v-5v, etc. However, VGA ...
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1answer
41 views

Ribbon Connector And Custom Graphics Card

I understand how to make a homemade VGA connection using resistor ladders or ICs, like is done in this tutorial. http://dqydj.net/how-to-produce-640x480-vga-color-video-from-an-arduino/ Is there any ...
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1answer
111 views

Identifying Feature on VGA PCB

I am reverse-engineering a board which provides a VGA output signal for connecting an oscilloscope to an external monitor. I have quite a bit of experience with PCB design but there is a feature on ...
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4answers
1k views

How is it possible to drive VGA displays at such high pixel clock frequencies?

I'm working on a digital circuit using discrete components to drive a 640x480 VGA display in a 80x30 text mode. For a 640x480 display, the pixel clock is 25.175MHz, which has a period around 40ns. I ...
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1answer
67 views

Is it possible to know CRT monitor VGA wires that have no color standards

Actually I know that rgb wires are thicker than the others also they r coax wires. But how to destinguish Vsync and Hsync wires and the respective ground wire for each signal when the wire colors ...
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1answer
156 views

VGA timing difference in pixel frequency

I'm trying to determine what is the correct timing for 640x480 VGA. Using Tinyvga.com for 640x480@60Hz I get a pixel frequency of 25.2 Mhz and not 25.175 Mhz. 800*525*60 = 25200000 I have wrote ...
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2answers
108 views

FPGA: possible to use PC as I/O?

I'm a beginner in FPGAs and I would like to implement a basic CPU with a simple VGA display. If I have a FPGA that has USB-UART could I use my own PC monitor as a display? What about sending input ...
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2answers
4k views

VGA to composite circuit. Does it work?

So I found a VGA to composite passive converter circuit online, and was wondering if it would work, if the vga timings were modified to match the timing of composite. Here is a relevant schematic:
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2answers
575 views

Unable to figure out VGA [Verilog]

After doing plenty of research on how to generate VGA signals and looking at a few code examples, I attempted to write my a simple VGA signal generator that just displays a single solid color on the ...
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2answers
68 views

Fitting USB Data in Cat5 Cable with External Power

I have a camera system at home with a DVR, which connects to a VGA monitor and mouse with which you can read and edit its settings (the cameras can be accessed over the Internet). I've been trying to ...
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1answer
848 views

How Significant is VGA Impedance Matching?

I've seen a multitude of different resistor DAC solutions for a VGA signal, however they almost always have an impedance of >200 ohms per color, e.g. when I've been lead to believe that we want to ...
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2answers
582 views

VGA cable arcing against computer case

I've tried to turn on my old PC with my old LCD monitor, which is powered by a kettle cable directly from mains, no power supply brick). When trying to get it to work, I have noticed the following ...
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3answers
535 views

YPbPr, VGA, Basys3

The Basys3 (a Digilent FPGA) manual says that the VGA analog outputs can drive between 0 and 0.7 volts. Does anyone know if, from a purely analog perspective, this can drive “component video”, ...
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2answers
334 views

VGA impedance matching

i have VGA in one side of my circuit and I want to connect that to a connector with 50 ohm impedance. after that I must convert 50 ohm impedance to 75 ohm, because I have a vga cable in other side. in ...
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1answer
312 views

Vivado Video IPs not working as expected

I've been trying to understand how to utilize AXI-Stream IPs for Video processing and display via VGA for a few days now, but can't seem to get any circuit to work. Here is a test circuit I created: ...
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2answers
1k views

Using old laptop LCD as external VGA screen [closed]

I have a few old laptops with good LCD panels that I wish to salvage and use as external VGA screen on other computers. I'am no expert in electronics but I work with computers and know the basics of ...
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2answers
1k views

Resistor DAC and buffer for VGA output

I'm in the process of designing a very simple binary weighted resistor DAC for an output stage of a RGB VGA driver. There will be 3 bits for R and G components and 2 for B. The output signal is analog ...
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1answer
524 views

how to show a picture on monitor through VGA from basys3 [closed]

I must find a picture and upload it into my basys3 board then I must show it on monitor through VGA cable. I dont know how to do that. What are the steps I must take?
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1answer
926 views

Why doesn't my VGA implementation using an AVR microcontroller work?

Problem I'm trying to generate the appropriate signal output for interfacing an AVR ATmega328P microcontroller with an LCD monitor, via the VGA specification. The VGA specification I am trying to ...
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1answer
322 views

VGA Output for 640 x 360 (16:9) Display for LCD monitor [closed]

I'm currently designing a TTL-based device to output VGA signals to a 16:9 aspect ratio LCD Monitor with a frame rate of 60 Hz. I hove mostly been referring to this question on how the VGA protocol ...
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1answer
106 views

Character mask VGA display

Im building a VGA (640x480@60Hz) adapter for my homebrew project but i dont have enought memory to store a framebuffer. Since im using 8 bit memory i plan to do 8 bit color, but 8 colors would be ...
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1answer
441 views

FPGA based VGA controller to drive PC monitor

I have implemented a VGA controller in FPGA, for 800x600 resolution @60Hz. Can I use it to drive a PC monitor ? In the PC's monitor resolution settings, it's seen that it supports multiple resolution ...
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1answer
141 views

s25fs256s serial flash not responding with RTD2660

Hello guys,, I am interfacing RTD2660 with s25fs256s serial flash using SPI. but when i send the command_type(0x46 (comman instruction type is read)) and command_data(0x9f (command for ...
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1answer
1k views

EGA display converting to VGA - screen's shaking

I've recently tried to make conversion from EGA (probably, couldn't get scope to verify) to VGA to replace an old factory CRT monitor to LCD. Screen displays fine but it appears to shake vertically ...
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3answers
303 views

VGA Image Refreshing

Hey everyone I am looking into VGA protocol. I have researched a lot but only thing I could not figure out is this: Does VGA vertical sync and horizontal sync needs to be sent over and over to keep ...
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1answer
642 views

YPbPr to VGA (consoles on monitor)

So the main idea is to take the component video of my consoles and convert them to VGA using the LM1881 IC, to strip the sync signal. If I was going to plug the green cable from my PS2 component into ...