AT24CX Library

Library for using the Atmels EEPROM AT24C32/AT24C64/AT24C128/AT24C256/AT24C512 in Arduino projects. See https://oberguru.net/elektronik/eeprom/at24cx-at24c32-at24c64-at24c128-at24c256-at24c512.html for definitons and differences.

Written by Christian Paul, 2014 - 2015.

Modified by Rushikesh Patel, 2019

This software is released under the terms of the MIT license. See the file LICENSE or LIZENZ for details, please.

You can use any of the eight possibles EEPROM devices on the I2C bus.

Constructor

For AT24C32-512:
 AT24CX(byte pageSize);
For AT24CM01,AT24CM02:
 AT24CM01(byte index);
 AT24CM02(byte index);

use the device with index 0 and given page size. You can select a device with given index between 0 and 8 with constructor

AT24CX(byte index, byte pageSize); //for AT24C32-512

Then, you can write or read single byte from the EEPROM with

void write(unsigned int address, byte data);
byte read(unsigned int address);

or write and read an array of bytes with

void write(unsigned int address, byte *data, int n);
void read(unsigned int address, byte *data, int n);

For writing integers, long, float, double or sequences of chars you can use the following functions

void writeInt(unsigned int address, unsigned int data);
void writeLong(unsigned int address, unsigned long data);
void writeFloat(unsigned int address, float data);
void writeDouble(unsigned int address, double data);
void writeChars(unsigned int address, char *data, int length);

Reading the values is done by using

unsigned int readInt(unsigned int address);
unsigned long readLong(unsigned int address);
float readFloat(unsigned int address);
double readDouble(unsigned int address);
void readChars(unsigned int address, char *data, int n);

Alternative you can use the individual classes with predefined page sizes:

AT24C32();
AT24C64();
AT24C128();
AT24C256();
AT24C512();
AT24CM01();
AT24CM02();

or with different index than 0:

AT24C32(byte index);
AT24C64(byte index);
AT24C128(byte index);
AT24C256(byte index);
AT24C512(byte index);
AT24CM01(byte index);
AT24CM02(byte index);

For AT24CM01/02 individual classes should be used rather than using the AT24CX class, because they have the logic for modifying the i2c address according to the data word address being read/written.