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[on:]

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?

thx
Ralph

[Reply #1 on:]

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?

thx
Ralph

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.

[Reply #2 on:]

thanks for the info. What other processors are available. Are they C++ or a different language.

[Reply #3 on:]

thanks for the info. What other processors are available. Are they C++ or a different language.

There are many different embedded processors, though a lot of them are more for large scale development where you have an expensive debug station, and you buy the chips in units of 10,000 or more.  I assume a lot of people reading these groups are more hobby programmers or who are looking for smaller/cheaper setups.

The main chip that people talk about is the ARM.  This is a 32-bit chip (Arduino is an 8-bit chip), and you can get it in many different price points and configurations.  Some that I've bookmarked include:

• Simplecortex -- http://imall.iteadstudio.com/featured-product/im120410002.html
• Arduino Due -- this isn't available yet, but presumably when it is available, you will be able to migrate existing AVR sketches to the new machine
• Mbed -- http://mbed.org/
• Beaglebone -- http://www.adafruit.com/products/513
• Rasberry PI -- http://www.raspberrypi.org/ -- this is more of a general purpose cheap computer, but I suspect eventually the infrastructure will be there for embedded programming, but for now it might be better to consider one of the other alternatives.
  

[Reply #4 on:]

VGA option: http://shop.4dsystems.com.au/vga-embedded-vga-graphics-modules/281-9004.html

Michael's comments on the limitations of the Arduinos still apply of course and you should think of this as a "graphics card" for your Arduino.

More details on the chip itself: http://www.4dsystems.com.au/prod.php?id=87. Certainly looks like it'd be fun to play with.

[Reply #5 on:]

Another graphics processing chip is SmartGPU: http://vizictechnologies.com/.  I know nothing about this, other than the link I provided.  The 4D systems chip also looks interesting.

[Reply #6 on:]

I forgot, at 8-10", you might better served with an Android tablet.  However, I don't know much about programming Android systems.

[Reply #7 on:]

VGA option: http://shop.4dsystems.com.au/vga-embedded-vga-graphics-modules/281-9004.html

Michael's comments on the limitations of the Arduinos still apply of course and you should think of this as a "graphics card" for your Arduino.

More details on the chip itself: http://www.4dsystems.com.au/prod.php?id=87. Certainly looks like it'd be fun to play with.

Sparkfun is selling this product too:

https://www.sparkfun.com/products/10329?

I think this product answers the OP's question.  This looks like the way to go if you want to control a screen via Arduino.  It outboards the video memory and gives you a serial interface.  Now, it doesn't look like simple sailing here but it looks like it works.  It also answers the eventual "42 or 50 or 60 inches" question if your TV has a VGA port on it like mine does.