Digital RGB

Ken Peterson

I have a propeller on order and we're thinking of applying it to a project involving a small 320 x 240 LCD touch screen.· The interface is 6-bit digital RGB input.· I wonder how hard it would be to drive it with the Propeller.· ·We also have the option of NTSC, but image quality isn't as nice and we're trying to reduce the number of components.

I think the two bits per color that are commonly used for the VGA output could be used on the high bits of the digital RGB.· I think there are some other additional timing signals too.

Any thoughts?

Mike Green

The Propeller's video generator can shift out 2 bits per color channel per pixel. You can use those bits any way you want. There has been some discussion of using more than one cog at a time to provide multiples of 2 bits per pixel by syncing the cogs. The main problem is that there's limited main memory for the video buffer. It is possible to attach static RAM to a Propeller to serve as an external video buffer. The Hydra will soon have an external static RAM with control logic to support its use as a video buffer (look on the Hydra forum for a discussion of this).

All of this is a way to say that the Propeller is very flexible, the video generator is pretty flexible. It all depends on the specifics of what you want to accomplish and whether you're comfortable writing your own video driver or modifying an existing driver for this device.