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FAT filesystem using NVM Media

This application shows an example of implementing a FAT disk in the device internal Flash memory.

Description

File System Operations on NVM:

  • Application places a FAT disk image consisting of a Master Boot Record (MBR) sector, Logical Boot Sector, File allocation Table, and Root Directory Area in the internal Flash memory (NVM)

  • During execution, the application first opens an existing file named FILE.TXT and performs following file system related operations:
    • SYS_FS_FileStat
    • SYS_FS_FileSize
    • SYS_FS_FileSeek
    • SYS_FS_FileEOF
  • It tries to read the file and checks if string “Data” is present. If present it continues to next step or it fails the application

  • Finally, the string “Hello World” is written to this file. The string is then read and compared with the string that was written to the file. If the string compare is successful, An LED indication is provided

File system layer uses:

  • Memory driver to communicate with underlying NVM media

Downloading and building the application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/fs/nvm_fat/firmware .

To build the application, refer to the following table and open the project using its IDE.

Project Name Description
pic32mx470_curiosity.X MPLABX project for Curiosity PIC32MX470 Development Board
pic32mx_eth_sk2.X MPLABX project for PIC32 Ethernet Starter Kit
pic32mx_sk.X PIC32MX Starter Kit
   

Setting up the hardware

The following table shows the target hardware for the application projects.

Project Name Board
pic32mx470_curiosity.X Curiosity PIC32MX470 Development Board
pic32mx_eth_sk2.X PIC32 Ethernet Starter Kit
pic32mx_sk.X PIC32MX Starter Kit
   

Setting up Curiosity PIC32MX470 Development Board

  • Connect mini USB cable to the ‘Debug USB’ connector(J3) on the board to the computer

Setting up PIC32 Ethernet Starter Kit

  • Connect the Debug USB port on the board to the computer using a mini USB cable

Setting up PIC32MX Starter Kit

  • Connect mini USB cable to the ‘Debug USB’ connector(J1) on the board to the computer

Running the Application

  1. Build and program the application using its IDE
  2. Press Switch to start the file operations
  3. The LED is turned ON when the File FILE.TXT has the app data “Hello World” written in it

Refer to the following table for switch and LED name:

Board Switch name LED Name
Curiosity PIC32MX470 Development Board S1 LED1
PIC32 Ethernet Starter Kit SW1 LED1
PIC32MX Starter Kit SW1 LED3
     


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