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Topic: 7 inch led touchscreen (Read 3 times) previous topic - next topic


I would imagine that it would be either impossible or very complicated with reduced functionality on an Arduino.  The screen you mention is 800x480 pixels, which is 384,000 bytes using 1 byte for the colors (375k).  Using 1 byte will give you 256 possible colors.  A more common way to represent the image is to use 3 bytes (1 byte for each of the 3 primary colors) which is 1,152,000 bytes (1.1m).  Given the Mega only has 8k of SRAM and 256k of flash memory (the Uno has 2k/32k, the Leonardo 2.5k/32k), there is no way to even hold the entire image in memory to be able to write it out 30 times a second.  If you had just a few images you were using, in theory it might be possible to store them on a SD card and rapidly copy them from the card to the display.


With over 375k bytes for just the screen size it sounds like an impossibility.  However lots of things seem impossible until tried.  If I was to use a sd card it wouldn't be for pictures it would be for bar graph functions and the such.  It sounds like the arduino would work with a 7 inch screen if the onboard chip had larger SRAM.  Thanks for the facts Michael .


Yeah the screens processor can help alot, that's what I like about the 4dsystems one, its basically got its own processor that you can make complex commands on and then have the arduino trigger those and save the arduinos memory for something else

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