I need to design a board that will have to access external, removable storage of less than 5MB. The CPU needs to be an AVR with a USART and a handful of GPIO. The most CPU-intensive thing it will be doing is reading data from the external storage medium and outputting it on the USART at about 500 kbps. A USB thumb drive or SD card would seem to be the obvious choices, but I've never interfaced to either. I was wondering if one were obviously better or easier to implement than the other. I realize there are AVRs that handle most of the h/w interface for USB, and SD cards are SPI-based, so that h/w is also covered by the AVR, so I assume it's mostly a s/w question. Am I mistaken? If not, is the s/w side easier for one than the other? I'll be using C, so I assume it's mostly a question of finding and implementing the right library, but, again, I'm assuming. Thanks for any tips.
Joined: Tue. Apr 1, 2003
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