All the lcds I see here are so small. I have a project in mind where I display an image but I want it on a 800x600 10.4 inches screen. Can I do that? What LCDs are available? Are there projects that show this? Do I need a LCD controller board?
The Arduino with the largest SRAM is the Mega with 8 kilobytes of read/write memory. One 800x600 image would take:
- 1.4 megabytes of memory using the common 3 bytes for each pixel to give a full colors
- 47 kilobytes of memory using a single byte for each pixel, which you have only 256 colors available
So you wouldn't be able to hold a single image in memory. If you have static images, you might be able to store them on a SD card, and busily read the card for the next few bytes, and spit those out as fast as you can. I suspect however, the Arduinos might not be fast enough to do this 30 times a second for the refresh cycle.
There is the Video Experimenter shield (http://nootropicdesign.com/ve/
) that would let you overlay lo-res graphics over an existing video stream that should be enough for something like a car backup camera. I bought one last week, but I haven't had time to use it. There is also the Gameduino shield which allows you to create 400x300 images (http://excamera.com/sphinx/gameduino/
The other option is to move to a different embedded processor that has more memory to form the image and runs faster.