/*-----------------------------------------------------------------------------*
* extEEPROM.h - Arduino library to support external I2C EEPROMs. *
* *
* This library will work with most I2C serial EEPROM chips between 2k bits *
* and 2048k bits (2M bits) in size. Multiple EEPROMs on the bus are supported *
* as a single address space. I/O across block, page and device boundaries *
* is supported. Certain assumptions are made regarding the EEPROM *
* device addressing. These assumptions should be true for most EEPROMs *
* but there are exceptions, so read the datasheet and know your hardware. *
* *
* The library should also work for EEPROMs smaller than 2k bits, assuming *
* that there is only one EEPROM on the bus and also that the user is careful *
* to not exceed the maximum address for the EEPROM. *
* *
* Library tested with: *
* Microchip 24AA02E48 (2k bit) *
* 24xx32 (32k bit, thanks to Richard M) *
* Microchip 24LC256 (256k bit) *
* Microchip 24FC1026 (1M bit, thanks to Gabriele B on the Arduino forum) *
* ST Micro M24M02 (2M bit) *
* *
* Library will NOT work with Microchip 24xx1025 as its control byte does not *
* conform to the following assumptions. *
* *
* Device addressing assumptions: *
* 1. The I2C address sequence consists of a control byte followed by one *
* address byte (for EEPROMs <= 16k bits) or two address bytes (for *
* EEPROMs > 16k bits). *
* 2. The three least-significant bits in the control byte (excluding the R/W *
* bit) comprise the three most-significant bits for the entire address *
* space, i.e. all chips on the bus. As such, these may be chip-select *
* bits or block-select bits (for individual chips that have an internal *
* block organization), or a combination of both (in which case the *
* block-select bits must be of lesser significance than the chip-select *
* bits). *
* 3. Regardless of the number of bits needed to address the entire address *
* space, the three most-significant bits always go in the control byte. *
* Depending on EEPROM device size, this may result in one or more of the *
* most significant bits in the I2C address bytes being unused (or "don't *
* care"). *
* 4. An EEPROM contains an integral number of pages. *
* *
* To use the extEEPROM library, the Arduino Wire library must also *
* be included. *
* *
* Jack Christensen 23Mar2013 v1 *
* 29Mar2013 v2 - Updated to span page boundaries (and therefore also *
* device boundaries, assuming an integral number of pages per device) *
* 08Jul2014 v3 - Generalized for 2kb - 2Mb EEPROMs. *
* *
* Paolo Paolucci 22-10-2015 v3.2 *
* 09-01-2016 v3.2 Add update function. *
* *
* External EEPROM Library by Jack Christensen is licensed under CC BY-SA 4.0, *
* http://creativecommons.org/licenses/by-sa/4.0/ *
*-----------------------------------------------------------------------------*/
/*
* tekka 2018:
* Re-implementing extEEPROM::update(unsigned long addr, byte value);
*/
#ifndef extEEPROM_h
#define extEEPROM_h
#include <Arduino.h>
#include <Wire.h>
//EEPROM size in kilobits. EEPROM part numbers are usually designated in k-bits.
enum eeprom_size_t {
kbits_2 = 2,
kbits_4 = 4,
kbits_8 = 8,
kbits_16 = 16,
kbits_32 = 32,
kbits_64 = 64,
kbits_128 = 128,
kbits_256 = 256,
kbits_512 = 512,
kbits_1024 = 1024,
kbits_2048 = 2048
};
//EEPROM addressing error, returned by write() or read() if upper address bound is exceeded
const uint8_t EEPROM_ADDR_ERR = 9;
/** extEEPROM class */
class extEEPROM
{
private:
// the private attribute used to comunicate with the correct I2C SERCOM
TwoWire *communication;
public:
/**
* I2C clock frequencies
*/
enum twiClockFreq_t {
twiClock100kHz = 100000, //!< twiClock100kHz
twiClock400kHz = 400000 //!< twiClock400kHz
};
/**
* @brief Constructor
* @param deviceCapacity
* @param nDevice
* @param pageSize
* @param eepromAddr
*/
extEEPROM(eeprom_size_t deviceCapacity, byte nDevice, unsigned int pageSize,
byte eepromAddr = 0x50);
// It is ready for every I2C Sercom, by default use the main Wire
byte begin(twiClockFreq_t twiFreq = twiClock100kHz, TwoWire *_comm=&Wire); //!< begin()
byte write(unsigned long addr, byte *values, unsigned int nBytes); //!< write()
byte write(unsigned long addr, byte value); //!< write()
byte read(unsigned long addr, byte *values, unsigned int nBytes); //!< read()
int read(unsigned long addr); //!< read()
byte update(unsigned long addr, byte *values, unsigned int nBytes); //!< update()
byte update(unsigned long addr, byte value); //!< update()
unsigned long length(); //!< length()
private:
uint8_t _eepromAddr; //eeprom i2c address
uint16_t _dvcCapacity; //capacity of one EEPROM device, in kbits
uint8_t _nDevice; //number of devices on the bus
uint16_t _pageSize; //page size in bytes
uint8_t _csShift; //number of bits to shift address for chip select bits in control byte
uint16_t _nAddrBytes; //number of address bytes (1 or 2)
unsigned long _totalCapacity; //capacity of all EEPROM devices on the bus, in bytes
};
#endif