EEPROM Class

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Utility

This library enables use of the Data Flash memory mounted on the MCU as EEPROM that enables the retention of data even after power off. With 32KB of EEPROM, the memory can be reprogrammed approximately 50,000 times. To use as the EEPROM, specify #include <eeprom.h>.

read

Description

Reads 1 byte from the EEPROM address.

Syntax

unsigned char EEPROM.read(unsigned long address)

Parameters

address: (0～32767)

Returns

Data read from the EEPROM

write

Description

Writes (stores) 1 byte of data in the EEPROM.

Syntax

int EEPROM.write(unsigned long address, unsigned char data)

Parameters

address: (0～32767); data: Data to be written

Returns

None

Sample program for EEPROM.write and EEPROM.read. The position of the LED flash changes by turning GR-KAEDE on or off.

#include <Arduino.h>
#include <eeprom.h>
void setup()
{
    pinMode(PIN_LED0, OUTPUT);
    pinMode(PIN_LED1, OUTPUT);
    pinMode(PIN_LED2, OUTPUT);
    pinMode(PIN_LED3, OUTPUT);
     
    uint8_t mode = EEPROM.read(0);
    if(mode == 0){
        digitalWrite(PIN_LED0, HIGH);
        EEPROM.write(0, 1);
    } else if (mode == 1){
        digitalWrite(PIN_LED1, HIGH);
        EEPROM.write(0, 2);
    } else if (mode == 2){
        digitalWrite(PIN_LED2, HIGH);
        EEPROM.write(0, 3);
    } else {
        digitalWrite(PIN_LED3, HIGH);
        EEPROM.write(0, 0);
    }
}
  
void loop()
{
}