EEPROM (EEPROM Class)

The microcontroller on the GR-COTTON board has Data Flash memory that can be used like EEPROM. The values of EEPROM are kept when the board is turned off. This library enables you to read and write those bytes. 8K bytes are available.

If you use, #include <EEPROM.h> should be described.

read

Description
Reads a byte from the EEPROM.
Syntax
byte EEPROM.read(int address)
Parameters
address: The location to read from. (0 to 0x1fff)
Returns
The value stored in that location (byte)

write

Description
Writes a byte to the EEPROM.
Syntax
EEPROM.write(int address, byte data)
Parameters
address: The location to write to (0 to 0x1fff)
data: The value to write (0 to 255)
Returns
None

Example

The mode is stored and the color of the LED is changed every time the power is turned on.


#include <Arduino.h>
#include <EEPROM.h>
 
#define LED_OFFSET 22
uint8_t mode;
void setup() {
  mode = EEPROM.read(0);
  mode++;
  if(mode > 2){
    mode = 0;
  }
  pinMode(mode + LED_OFFSET, OUTPUT);
  EEPROM.write(0, mode);
}
   
void loop() {
  digitalWrite(mode + LED_OFFSET, LOW);
  delay(100);
  digitalWrite(mode + LED_OFFSET, HIGH);
  delay(100);
 
}