EEPROM Class

Digital I/O
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Utility

This library enables use of the data flash memory mounted on the microcontroller (MCU) as EEPROM which enables retention of data even after power off. With 32KB of EEPROM, the memory can be reprogrammed approximately 50,000 times.

To use this EEPROM library, 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

This is a sample for EEPROM.write and EEPROM.read. The position of the LED flash changes by turning GR-SAKURA 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()
{
}