Subversion Repositories idreammicro-arduino

/**************************************************************************//**

 * \brief EEPROM 24C128 / 24C256 library for Arduino

 * \author Copyright (C) 2012  Julien Le Sech - www.idreammicro.com

 * \version 1.0

 * \date 20120203

 *

 * This file is part of the EEPROM 24C128 / 24C256 library for Arduino.

 *

 * This library is free software: you can redistribute it and/or modify it under

 * the terms of the GNU Lesser General Public License as published by the Free

 * Software Foundation, either version 3 of the License, or (at your option) any

 * later version.

 *

 * This library is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more

 * details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program. If not, see http://www.gnu.org/licenses/

 ******************************************************************************/

/**************************************************************************//**

 * \file Eeprom24C128_256.cpp

 ******************************************************************************/

/******************************************************************************

 * Header file inclusions.

 ******************************************************************************/

#include <Arduino.h>

#include <Wire.h>

#include <Eeprom24C128_256.h>

/******************************************************************************

 * Private macro definitions.

 ******************************************************************************/

/**************************************************************************//**

 * \def EEPROM__PAGE_SIZE

 * \brief Size of a page in EEPROM memory.

 * This size is given by EEPROM memory datasheet.

 ******************************************************************************/

#define EEPROM__PAGE_SIZE         64

/**************************************************************************//**

 * \def EEPROM__RD_BUFFER_SIZE

 * \brief Size of input TWI buffer.

 * This size is equal to BUFFER_LENGTH defined in Wire library (32 bytes).

 ******************************************************************************/

#define EEPROM__RD_BUFFER_SIZE    BUFFER_LENGTH

/**************************************************************************//**

 * \def EEPROM__WR_BUFFER_SIZE

 * \brief Size of output TWI buffer.

 * This size is equal to BUFFER_LENGTH - 2 bytes reserved for address.

 ******************************************************************************/

#define EEPROM__WR_BUFFER_SIZE    (BUFFER_LENGTH - 2)

/******************************************************************************

 * Public method definitions.

 ******************************************************************************/

/**************************************************************************//**

 * \fn Eeprom24C128_256::Eeprom24C128_256(byte deviceAddress)

 *

 * \brief Constructor.

 *

 * \param   deviceAddress   EEPROM address on TWI bus.

 ******************************************************************************/

Eeprom24C128_256::Eeprom24C128_256

(

    byte deviceAddress

){

    m_deviceAddress = deviceAddress;

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::initialize()

 *

 * \brief Initialize library and TWI bus.

 *

 * If several devices are connected to TWI bus, this method mustn't be

 * called. TWI bus must be initialized out of this library using

 * Wire.begin() method.

 ******************************************************************************/

void

Eeprom24C128_256::initialize()

{

    Wire.begin();

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::writeByte(

 * word address,

 * byte data)

 *

 * \brief Write a byte in EEPROM memory.

 *

 * \remarks A delay of 10 ms is required after write cycle.

 *

 * \param   address Address.

 * \param   data    Byte to write.

 ******************************************************************************/

void

Eeprom24C128_256::writeByte

(

    word    address,

    byte    data

){

    Wire.beginTransmission(m_deviceAddress);

    Wire.write(address >> 8);

    Wire.write(address & 0xFF);

    Wire.write(data);

    Wire.endTransmission();

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::writeBytes(

 * word     address,

 * word     length,

 * byte*    p_data)

 *

 * \brief Write bytes in EEPROM memory.

 *

 * \param       address Start address.

 * \param       length  Number of bytes to write.

 * \param[in]   p_data  Bytes to write.

 ******************************************************************************/

void

Eeprom24C128_256::writeBytes

(

    word    address,

    word    length,

    byte*   p_data

){

    // Write first page if not aligned.

    byte notAlignedLength = 0;

    word pageOffset = address % EEPROM__PAGE_SIZE;

    if (pageOffset > 0)

    {

        notAlignedLength = EEPROM__PAGE_SIZE - pageOffset;

        writePage(address, notAlignedLength, p_data);

        length -= notAlignedLength;

    }

    if (length > 0)

    {

        address += notAlignedLength;

        p_data += notAlignedLength;

        // Write complete and aligned pages.

        word pageCount = length / EEPROM__PAGE_SIZE;

        for (word i = 0; i < pageCount; i++)

        {

            writePage(address, EEPROM__PAGE_SIZE, p_data);

            address += EEPROM__PAGE_SIZE;

            p_data += EEPROM__PAGE_SIZE;

            length -= EEPROM__PAGE_SIZE;

        }

        if (length > 0)

        {

            // Write remaining uncomplete page.

            writePage(address, EEPROM__PAGE_SIZE, p_data);

        }

    }

}

/**************************************************************************//**

 * \fn byte Eeprom24C128_256::readByte(word address)

 *

 * \brief Read a byte in EEPROM memory.

 *

 * \param   address Address.

 *

 * \return Read byte.

 ******************************************************************************/

byte

Eeprom24C128_256::readByte

(

    word address

){

    Wire.beginTransmission(m_deviceAddress);

    Wire.write(address >> 8);

    Wire.write(address & 0xFF);

    Wire.endTransmission();

    Wire.requestFrom(m_deviceAddress, (byte)1);

    byte data = 0;

    if (Wire.available())

    {

        data = Wire.read();

    }

    return data;

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::readBytes(

 * word     address,

 * word     length,

 * byte*    p_data)

 *

 * \brief Read bytes in EEPROM memory.

 *

 * \param       address Start address.

 * \param       length  Number of bytes to read.

 * \patam[in]   p_data  Byte array to fill with read bytes.

 ******************************************************************************/

void

Eeprom24C128_256::readBytes

(

    word    address,

    word    length,

    byte*   p_data

){

    byte bufferCount = length / EEPROM__RD_BUFFER_SIZE;

    for (byte i = 0; i < bufferCount; i++)

    {

        word offset = i * EEPROM__RD_BUFFER_SIZE;

        readBuffer(address + offset, EEPROM__RD_BUFFER_SIZE, p_data + offset);

    }

    byte remainingBytes = length % EEPROM__RD_BUFFER_SIZE;

    word offset = length - remainingBytes;

    readBuffer(address + offset, remainingBytes, p_data + offset);

}

/******************************************************************************

 * Private method definitions.

 ******************************************************************************/

/**************************************************************************//**

 * \fn void Eeprom24C128_256::writePage(

 * word     address,

 * byte     length,

 * byte*    p_data)

 *

 * \brief Write page in EEPROM memory.

 *

 * \param       address Start address.

 * \param       length  Number of bytes (EEPROM__PAGE_SIZE bytes max).

 * \param[in]   p_data  Data.

 ******************************************************************************/

void

Eeprom24C128_256::writePage

(

    word    address,

    byte    length,

    byte*   p_data

){

    // Write complete buffers.

    byte bufferCount = length / EEPROM__WR_BUFFER_SIZE;

    for (byte i = 0; i < bufferCount; i++)

    {

        word offset = i * EEPROM__WR_BUFFER_SIZE;

        writeBuffer(address + offset, EEPROM__WR_BUFFER_SIZE, p_data + offset);

    }

    // Write remaining bytes.

    byte remainingBytes = length % EEPROM__WR_BUFFER_SIZE;

    word offset = length - remainingBytes;

    writeBuffer(address + offset, remainingBytes, p_data + offset);

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::writeBuffer(

 * word     address,

 * byte     length,

 * byte*    p_data)

 *

 * \brief Write bytes into memory.

 *

 * \param       address Start address.

 * \param       length  Number of bytes (EEPROM__WR_BUFFER_SIZE bytes max).

 * \param[in]   p_data  Data.

 ******************************************************************************/

void

Eeprom24C128_256::writeBuffer

(

    word    address,

    byte    length,

    byte*   p_data

){

    Wire.beginTransmission(m_deviceAddress);

    Wire.write(address >> 8);

    Wire.write(address & 0xFF);

    for (byte i = 0; i < length; i++)

    {

        Wire.write(p_data[i]);

    }

    Wire.endTransmission();

    // Write cycle time (tWR). See EEPROM memory datasheet for more details.

    delay(10);

}

/**************************************************************************//**

 * \fn void Eeprom24C128_256::readBuffer(

 * word     address,

 * byte     length,

 * byte*    p_data)

 *

 * \brief Read bytes in memory.

 *

 * \param       address Start address.

 * \param       length  Number of bytes (EEPROM__RD_BUFFER_SIZE bytes max).

 * \param[in]   p_data  Buffer to fill with read bytes.

 ******************************************************************************/

void

Eeprom24C128_256::readBuffer

(

    word    address,

    byte    length,

    byte*   p_data

){

    Wire.beginTransmission(m_deviceAddress);

    Wire.write(address >> 8);

    Wire.write(address & 0xFF);

    Wire.endTransmission();

    Wire.requestFrom(m_deviceAddress, length);

    for (byte i = 0; i < length; i++)

    {

        if (Wire.available())

        {

            p_data[i] = Wire.read();

        }

    }

}