NerdKits - electronics education for a digital generation

You are not logged in. [log in]

NEW: Learning electronics? Ask your questions on the new Electronics Questions & Answers site hosted by CircuitLab.

Basic Electronics » I can haz speed!

April 27, 2010
by Hexorg
Hexorg's Avatar

Sorry for misspelled title - just had 2 hours of lolcats...

I'm still working on my LED display project, and I have some speed concerns. Right now with a standard 14Mhz nerdkit clock I can refresh one row of image in 1.3mS , which is about 90Hz screen refresh rate. It's good for displaying a static image, but I wanted to set up video streaming through UART, and I doubt I'll be able to fit it in the code... So is there an AVR that's actually supporting 29.4912MHz clocks natively? I found crystalls at that frequency for 30 cents a piece.

April 27, 2010
by bretm
bretm's Avatar

According to the parametric table you'll need to go to XMega (32MHz) or 32-bit (66MHz). The mega's and tiny's only go up to 20MHz.

Raw video over UART seems like a tall order, though.

April 27, 2010
by Hexorg
Hexorg's Avatar

Ah, missed that page... Will there be any troubles of moving code to XMega?

Tthe "video" is going to be 16x16x24 bits per frame, so it shouldn't be that bad... Any other suggestions of getting that dinamically from PC?

I the other choice I was considering was some sort of external RAM that's at least 1.536kB - that way I can stotore 2 frames in there, and make AVR show first frame, while computer is writting second, and then flip them

Post a Reply

Please log in to post a reply.

Did you know that two resistors plus a transistor can be used to make a better voltage supply? Learn more...