Writing password to flash memory on Due

Hardware Arduino Due
1

Hello, i have an assignment to hand in 3 days in Arduino, and part of it is to write a password to Arduino Due flash memory and to be able to change it trough keypad (which i have), and even when the arduino is unplugged from power and re-plugged the password will be saved.
(being able to change it and to save the change is an important part).

i saw this library called "Due flash storage" but i have no idea how to use it and the examples there are kinda not understandable for me.
if anyone could help me i would really appreciate it :slight_smile:

2

Wow, if you don't understand those examples you're indeed in for a hard time...

But just whining about it doesn't get you anywhere. Chop it up into pieces (for example reading the keypad, handling it as a password and writing/reading it from flash) and start writing code. Don't expect to write the full program, take baby steps and write tests to see if you understand the code.

3

the keypad part is alright, i can handle it, and yes i am new to code and the only part i dont understand is the writing\ reading from the flash. and that's where i need help.

4

Then open up the example and tell us which part you don't understand :slight_smile:

5 
void setup() {
  Serial.begin(115200);
  byte b1 = 3;
  uint8_t b2 = 1;
  dueFlashStorage.write(0,b1);
  dueFlashStorage.write(1,b2);
  //dueFlashStorage.write(2,b2);
}

void loop() {
  // read from flash at address 0 and 1 and print them
  Serial.print("0:");
  Serial.print(dueFlashStorage.read(0));
  Serial.print(" 1:");
  Serial.print(dueFlashStorage.read(1));  
  
  // read from address 2, increment it, print and then write incremented value back to flash storage
  uint8_t i = dueFlashStorage.read(2)+1;
  Serial.print(" 2:");
  Serial.print(dueFlashStorage.read(2)); 
  dueFlashStorage.write(2,i);
  
  Serial.println();
  delay(1000);
}

See, Now i want to make a password 4 ints long, and i don't know where is the writing to flash part, and where do i read it from?

6

I said open it up, don't just post it here...

Benoson:
See, Now i want to make a password 4 ints long,

Why do you want to make it 4 int's long? Do you have a keyboard with 65535 keys? Or do you mean 4 numbers between 0 and 9 (inclusive)? That you can just store in a byte or leave it as a char (which is also a byte)

Benoson:
where is the writing to flash part

dueFlashStorage.write(0,b1);

Benoson:
and where do i read it from?

Serial.print(dueFlashStorage.read(0));
7

What does "(0,b1)" mean?

8

Address location 0
b1 is the variable but that should have been obvious.

Like the documentation says, it's almost like EEPROM on a Uno.

9

Writing password to flash memory on Due- some problem please help see below form

https://forum.arduino.cc/index.php?topic=556775.msg3797002#msg3797002