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I have a product consisting of two boxes, both running an RTOS (not picked yet, say FreeRTOS):

Box A will have:

  • an SD card and a FAT stack
  • an "external" USB device port with MSD to allow PC access to the SD card
  • "internal" USB device port to Box B with MSD

Box B

  • an "internal" USB host port to Box A with MSD

QUESTION: do I need a FAT stack in Box B to be able to access the SD card in Box A?

I realize this is a very basic question but I have not been able to find the answer anywhere. Thank you

ilnadi
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1 Answers1

0

As it turns out you do not need FAT on both ends. You need it at the Host end not the Device end. MSD takes over the SD Card at a low level so the file system is actually on the Host side. The way to access storage being managed at the Device end is to use MTP instead of MSD.

ilnadi
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