MMC Card Reader

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==[[Development Roadmap for MMC Card Reader]]==
==Development Roadmap==
*Contains directions for development
===Phase 1===
*Circuit design for interfacing MMC
===Phase 2===
*SPI driver for MMC
===Phase 3===
*Wrapper for file system in freertos_posix
===Phase 4===
*Test for normal read/write function
*hotswap (should not hang or cause voltage dip)
*multiple file read/write (protection)

Revision as of 18:59, 23 February 2009

This project aims to develop an MMC Card Reader, interfacing with a 8/16 bits embedded system such as the dsPic33F development board.



MultiMedia Card (MMC) is commonly used in portable devices due to their high density, rewritability and low cost. The use of MMC in embedded systems enables the systems to possess a removable, upgradeable and external mass storage.

MMC Manufacturers usually formats the cards in FAT12/FAT16/FAT32, and can be read/write in almost all computers. This project aims to integrate a FAT file system in freertos_posix for reading/writing files in MMC by 8/16-bit embedded systems. The API employs POSIX and Standard C-library standard for I/O operations.


  • Save large files (e.g. html) for application feature expansion
  • Provide storage space for upload and upgrade firmware remotely (e.g. over the Internet)
  • Save fonts, image files for GUI applications


  • File read/write access may be slow


  • See here for block diagram

Development Roadmap

Phase 1

  • Circuit design for interfacing MMC

Phase 2

  • SPI driver for MMC

Phase 3

  • Wrapper for file system in freertos_posix

Phase 4

  • Test for normal read/write function
  • hotswap (should not hang or cause voltage dip)
  • multiple file read/write (protection)

Circuit and PCB

Software Implementation

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