EEPROM (EEPROM Class)

Digital I/O
Analog I/O
Advanced I/O
Time
Math
Trigonometry
Random Numbers
Bits and Bytes
Interrupts
Serial Comm.

Servo Motor
Stepping Motor
Character LCD
EEPROM
SPI
I²C (Wire)
SD Card
SD (File Operations)
Ethernet
Ethernet (Server)
Ethernet (Client)
Firmata
Periodic Operation
Power Save
Clock (RTC)
SoftwareSerial
Utility

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

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);
 
}