DueFlashStorage saves non-volatile data for Arduino Due. The library is made to be similar to the EEPROM library. Uses flash block 1 per default.

• Non-volatile data storage. Resetting or loss of power to the Arduino will not affect the data.
• Similar to the standard EEPROM library
• Write and read byte by byte
• Write and read byte arrays to store arbitrary variable types (strings, structs, integers, floats)

Note: The flash storage is reset every time you upload a new sketch to your Arduino.

Inspiration and some code from Pansenti at https://github.com/Pansenti/DueFlash

Arduino.cc has some good instructions on how to add libraries: https://www.arduino.cc/en/Guide/Libraries

The easiest is just to open the library manager and search for "DueFlashStorage". Install the one from Sebastian Nilsson.

Remember that you also need to install the Arduino SAM Boards from the board manager: https://www.arduino.cc/en/Guide/Cores

// write the value 123 to address 0
dueFlashStorage.write(0,123);

// read byte at address 0
byte b = dueFlashStorage.read(0);

// say you want to store a struct with parameters:
struct Configuration {
  uint8_t a;
  uint8_t b;
  int32_t bigInteger;
  char* message;
  char c;
};
Configuration configuration;

// then write it to flash like this:
byte b2[sizeof(Configuration)]; // create byte array to store the struct
memcpy(b2, &configuration, sizeof(Configuration)); // copy the struct to the byte array
dueFlashStorage.write(4, b2, sizeof(Configuration)); // write byte array to flash at address 4

// and read from flash like this:
byte* b = dueFlashStorage.readAddress(4); // byte array which is read from flash at adress 4
Configuration configurationFromFlash; // create a temporary struct
memcpy(&configurationFromFlash, b, sizeof(Configuration)); // copy byte array to temporary struct

/* see example code for a working example */

This example will write 3 bytes to 3 different addresses and print them to the serial monitor. Try resetting the Arduino Due or unplug the power to it. The values will stay stored.

This example will write a struct to memory which is a very convinient way of storing configuration parameters. Try resetting the Arduino Due or unplug the power to it. The values will stay stored.