esp-idf/examples/storage/wear_levelling/README.md

Wear levelling example

This example demonstrates how to use wear levelling library and FATFS library to store files in a partition inside SPI flash. Example does the following steps:

1. Use an "all-in-one" esp_vfs_fat_spiflash_mount function to:
   • find a partition in SPI flash,
   • initialize wear levelling library using this partition
   • mount FAT filesystem using FATFS library (and format the filesystem, if the filesystem can not be mounted),
   • register FAT filesystem in VFS, enabling C standard library and POSIX functions to be used.
2. Create a file using fopen and write to it using fprintf.
3. Open file for reading, read back the line, and print it to the terminal.

Example output

Here is an typical example console output.

I (280) example: Mounting FAT filesystem
W (440) vfs_fat_spiflash: f_mount failed (13)
I (440) vfs_fat_spiflash: Formatting FATFS partition, allocation unit size=4096
I (660) vfs_fat_spiflash: Mounting again
I (660) example: Opening file
I (910) example: File written
I (910) example: Reading file
I (920) example: Read from file: 'written using ESP-IDF v3.1-dev-171-gf9ad17eee-dirty'
I (920) example: Unmounting FAT filesystem
I (1000) example: Done