Tag Archives: VGA

ATiny does 170×240 VGA with 8 Colors

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AtomicZombie @ avrfreaks.net used an ATtiny85 ATMEL microcontroller to produce a 170×240 VGA signal and also send audio along with video.

The original plan was to just bit bang some mono VGA and do up a Pong or Tetris game, but things went MUCH MUCH further than I ever thought possible, so over the next few weeks I will detail this fun project here. I call it The QUARK-85 VGA DEMO System.

So what can one do with an ATTINY-85 and no other external components, an 8 pin package that leaves ONLY 4 IO lines after you feed it a clock??

How about 4 color rock solid VGA with stereo sound!!!

ATiny does 170×240 VGA with 8 Colors – [Link]

HCS08 VGA Output

This reference design is a simple VGA signal generation that uses the Freescale’s MC9S08SH16VTJR, which is an 8-bit microcontroller that has Central Processor Unit (CPU) speed of 40MHz with a maximum bus frequency of 20MHz. It has an internal clock source module containing a Frequency-Locked Loop (FLL) controlled by internal or external reference. Its precision trimming of internal reference allows 0.2% resolution and 2% deviation over temperature and voltage with 1.5% deviation using internal temperature compensation. The simplest instructions such as NOP take 1 bus cycle, the other instructions take more cycles, and for example RTS takes 6 bus cycles.

The VGA signal has 5 components that include horizontal synchronization, vertical synchronization and three analog color signals. The analog color signal range is 0-0.7V with 75Ω impedance and sync signals are TTL signals. The device has a refresh rate of 60Hz with 640 x 480 resolutions, and the pixel clock is 25.175MHz. The display refresh rate is therefore slightly lower, somewhere around 57Hz. The implementation for video signal generation is in the form of an infinite loop where one loop cycle is equal to one video frame. During every frame the video signal is generated line by line. A subroutine was created that draws multiple lines, where the number of lines is expected in the A register. Every line is divided into 16 parts. Colors of these parts are stored in RAM. Pointer to this array is expected in the HX register. Each of the 3 color channels is 1 bit only having 8 available basic colors.

The device is very simple that adds character to an ordinary static image displayed in an old CRT display. This can be easily reprogrammed as desired by the user. A scrolling strip may be added that is implemented as a rotating buffer. The circuit can be easily constructed using only an MCU, crystal oscillator, VGA connector and few capacitors.

HCS08 VGA Output – [Link]

Building a simple VGA-adapter for 8-bit self made computer

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by aehparta @ tldr.fi:

My lifetime project: building an 8-bit computer using Z80 CPU. This week I had a bad flu and could not do anything useful so I decided to dig up my old plans for this project. I first re-designed many things, like power, CPU-board, IO-board and so on (my old plans were around 10 to 15 years old). After some thought I realized: When I get even the CPU-board working, I want to display some stuff! So why not build the display adapter first. Plus I planned to build the adapter in a way that it can be used separately from the computer itself. Easy thing to start with.

Building a simple VGA-adapter for 8-bit self made computer – [Link]

TWILight – VGA I²C breakout board

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blog.atx.name writes:

Some time ago, I stumbled upon an article about 25¢ I²C adapter. I usually use my Raspberry Pi to interface with I²C devices, but having it right on my notebook seemed like quite useful thing, so I decided to build a project around it. Altough the mentioned article says that I²C is not supported on Intel cards on Linux (all of this was tested on Dell Latitude E5530 which does have Intel HD4000), I decided to try anyway. A lot has probably changed since 2008 when it was written.

TWILight – VGA I²C breakout board – [Link]

Basic Arduino VGA

This project uses an Arduino UNO to create the proper timing signals for 800×600 VGA output. The output is a standard red/green/blue pattern. Not particularly exhilarating but a great starting point for any Arduino lover curious about generating VGA signals.

Basic Arduino VGA – [Link]

Android controlled VGA Scoreboard

fvicente writes:

The Scoreboard project is now finished and working!

The idea of this project is pretty simple: control a ping-pong electronic scoreboard from an Android bluetooth-enabled device. To do this, I used an ATtiny45 which main function is to display the current scores in a VGA monitor while reading from a bluetooth module UART interface waiting for “commands

DE0 Nano VGA Output

pyroelectro.com writes:

After my Masochist’s Video Card project won 2nd place in the 7400 contest, I got to choose one of many prizes being given away by Dangerous Prototypes. The prize I chose was the DE0 Nano FPGA development board, which, it turns out, is a pretty beefy little thing, despite its tiny size.

This article will look at how to build the same functionality that the Masochist’s Video Card (built only with 7400 logic IC’s) had, however this time we will use the DE0 Nano development board to complete the task, instead of wrist-breaking, pain-staking, masochist-loving wire-wrapping.

DE0 Nano VGA Output – [Link]

Masochist's Video Card

 

pyroelectro.com writes:

A friend of mine suggested that I build something for a 74xx TTL discrete logic contest at dangerous prototypes, so I figured why not? If you like this design, make sure to leave a comment on their website for my competition entry.
The Masochist’s video card is a pure TTL discrete logic design that generates the necessary video signals for VGA. The project name came about after the hours I spent wire-wrapping the project together yielded painfully raw fingertips. So be fore-warned if you duplicate this project, don’t abuse the wire-wrap tool!

Masochist’s Video Card – [Link]

Masochist’s Video Card

 

pyroelectro.com writes:

A friend of mine suggested that I build something for a 74xx TTL discrete logic contest at dangerous prototypes, so I figured why not? If you like this design, make sure to leave a comment on their website for my competition entry.
The Masochist’s video card is a pure TTL discrete logic design that generates the necessary video signals for VGA. The project name came about after the hours I spent wire-wrapping the project together yielded painfully raw fingertips. So be fore-warned if you duplicate this project, don’t abuse the wire-wrap tool!

Masochist’s Video Card – [Link]