I search for info about how can use Arduino as VGA tester or video card.
First credible article is Simple VGA/Video adapter who can use 8-bit AVR MCU like ATmega8, 328, etc:
Article is writted by Maxx Ibragmov and a their montage is:
On TV, resolution is 20 rows with 38 character each:
and on VGA monotor, resolution is 20 rows with 20 characters each:
I wanted fast result and try other adapter montage (without diodes):
First test was with info from article Arduino generated VGA (color) signal - Complete!
who use this schematic:
I use Arduino IDE 1.0.3 and my test image is:
NOTE (27.09.2017): Now site is "down", so you can download usefull files from https://github.com/LaboratorioDeGaragem/VGA-com-Arduino !
I try to reproduce a more complex image like in article Arduino generated VGA (color) signal - Complete! (other site, same author):
but image is not clean.. and I jump to other material find in article Basic Arduino VGA:
I use same Arduino IDE 1.0.3, but my test image is not same in original article:
Next step was to reproduce expermiments from Nick Gammon with VGA
First is a black/white VGA video card for 30 rows with 20 alphanumerical characters each. Schematic is simple:
This VGA video card use i2c protocol for comunicate with other Arduino board, but results are very poor on transmision data (author say: unfortunately incoming data (can) make the display "glitch"). I made a movie (explanations are in Romanian language, but you may can understund what I want to say):
Next test was with moving colour test image on VGA display, using this schematic:
and a image is:
I made a movie with image on VGA (saame, with explanations are in Romanian language):
Next step was to test VGAX library writted by Sandro Maffioda after Nick Gammon info.. on display resolution is 120x60px with 4 colours.
Schematic is simple:
You can made some combination:
1) red & green made: black, red, green & yellow:
2) red & blue made: black, red, blue, purple:
3) green & blue made: black, green, blue, cyan:
4) red & cyan (green + blue) made: black, red, cyan, white:
5) blue & yellow (red + green) made: black, yellow, blue, white:
6) green & purple (red + blue) made: black, green, purple, white:
I made some movies for understund more easy: