Tag Archives: VGA

VGADuino-II : The New 256 Color Graphic Shield for Arduino

Arduino is pretty much famous for the numerous shields it has. These plug-and-play shields make our life a lot easier while working on some complicated projects. Among all other shields, graphic shields are getting more and more popular. A graphic shield lets you show text, numbers, shapes, and even small images on a screen, using Arduino. VGADuino-II is a new graphic shield which lets you use your TV or any monitor with VGA 15 pin as a large screen for Arduino.

It’s very exciting that you won’t have to rely on those small displays which are stacked on the shield itself, anymore. Rather you are getting a whole TV or VGA monitor to display your data. As  Masih Vahida, the creator of VGADuino, says:

VGADuino is a shield that is made for Arduino with all the libraries and samples that user can easily stack it on the Arduino board and starts programming. it can connect Arduino to any kind of TV or Monitor with VGA 15 Pin connector.

VGADuino-II : The 256 color graphic shield for arduino
VGADuino-II: The 256 color graphic shield for Arduino

Key Features:

  • Internal functions to draw various shapes with AT-Commands and Arduino libraries
  • 11 Different font sizes with standard ASCII characters support
  • 256 color, 8bit RGB format
  • Having access to each pixel individually
  • Standard VGA DB15 output
  • Screen resolution: 800×600 60Hz
  • Actual pixels: 400×300 60Hz

Technical Details:

In VGADuino-II, NXP-LPC1756 ARM chip is used as the main microcontroller and XILINX XC95144XL CPLD for refreshing the display and taking care of the sync signals. There is also an SD Ram to keep the screen’s pixel color data.

In this version of VGADuino, each pixel is one byte, that means each pixel has 256 colors which are in standard 8bit RGB format. (3 bits for Red, 3 bits for Green and 2 bits for Blue).

It communicates with Arduino over UART using predefined AT command set. All relevant Arduino libraries are available to implement in code. The user can choose among all 11 fonts with definable background and foreground color of text.

VGADuino-II Technical Details
VGADuino-II Technical Details


VGADuino-II is available for $79. You may go here and back the Kickstarter project to get a VGADuino-II. All the groundbreaking features offered by VGADuino-II are making it a value for money. There is no risk at all. The design is tested and completed by the maker.

For a better understanding watch this video.


TFoC: FPGA & Forth = VGA


Here is a fun project, created from start to finish by Matthias Koch:

In itself, this is no big deal. The generated pattern is a 16×16 expanded pixel image, and 640×480 displays are pretty basic by now – although they’re fine for presenting text-mode information and retro games.

TFoC: FPGA & Forth = VGA – [Link]

F1200 Low-noise Digital IF VGA with FlatNoise

The F1200 of an IDT is a digitally controlled intermediate frequency differential variable gain amplifier that adjusts the gain either dynamically or as a one-time channel gain setting. The device has extremely low noise figure over the entire gain control range. It is packaged in compact 5×5 Thin QFNs with 200 ohm differential input and output impedances for ease of integration into the receiver lineup with IF frequencies up to 300MHz.

The device has exceptional DNL and INL simplifying digital compensation. It has extremely low Harmonic, IM2, and IM3 distortion that is necessary to drive an ADC directly in an IF sub-sampling application. The F1200 acts to enhance system SNR when VGA gain is reduced. The F1200 noise figure (NF) degrades only slightly (NF slope ~ -0.16 dB/dB) over a 13 dB control range while holding the output IP3 approximately constant. The resultant improvement in noise can enhance the system SNR up to 2 decibels at low gain settings relative to a standard VGA.

This design is used in either transmitter or receiver to add an adjustable gain element to the signal chain by increasing or decreasing the attenuation value. Other applications include base station, diversity receivers, digital pre-distortion, μ-wave point-to-point radios and public safety receivers.

F1200 Low-noise Digital IF VGA with FlatNoise – [Link]

ATiny does 170×240 VGA with 8 Colors


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]