Extended EEPROM library for Arduino
The EEPROMex library is an extension of the standard Arduino EEPROM library. It extends the functionality of the original Arduino EEPROM library with:
And find detailed explanation and samples of the functionality here: http://thijs.elenbaas.net/2012/07/extended-eeprom-library-for-arduino
This package can be downloaded in different manners
The aim of the library is to also support other standard data types: it currently implements writing and reading to int, long, float and double.
uint8_t read(int address); bool readBit(int address, byte bit) uint8_t readByte(int address); uint16_t readInt(int address); uint32_t readLong(int address); float readFloat(int address); double readDouble(int address);
Where address is the starting position in EEPROM, and the return value the value read from EEPROM.
bool write(int address, uint8_t value); bool writeByte(int address, uint8_t value); bool writeInt(int address, uint16_t value); bool writeLong(int address, uint32_t value); bool writeFloat(int address, float value); bool writeDouble(int address, double value);
The update functions are different from the write functions: they will check per byte if the current value differs and only update the the cell with a different value. This will not only reduce wear, and can also significantly reduce write time.
bool update(int address, uint8_t value); bool updateByte(int address, uint8_t value); bool updateInt(int address, uint16_t value); bool updateLong(int address, uint32_t value); bool updateFloat(int address, float value); bool updateDouble(int address, double);
The following functions implements reading and writing single bits:
bool readBit(int address, byte bit)
Where bit is the write position in the byte, ranging from [0..7], with bit 0 being the right-most. The return value is the read bit.
bool writeBit(int address, uint8_t bit, bool value) bool updateBit(int address, uint8_t bit, bool value)
Using the block functions any data can be read, written and updated:
int readBlock(int address, const T& value) int writeBlock(int address, const T& value) int updateBlock(int address, const T& value)
where T is the type of the data to read/write/update. This can be a basic type, but also a more complex type like a struct. The return value gives the number of bytes that have been read, written or updated.
One can also read/write arrays of data-blocks:
int readBlock(int address, const T; value, int items) int writeBlock(int address, const T; value, int items) int updateBlock(int address, const T; value, int items)
It is easy to burn out a memory cell in few minutes, so during debugging it would be very useful to limit the number of allowed writes. It is easy to put a bracket at the wrong location, and placing an EEPROM write inside of a loop, rather than outside, and introduce extensive writing causing wear. The following function helps limit the number of writes.
More writes than allowed will be refused and result in an error message. You can also set the address range used by the library:
setMemPool(int base, int memSize);
The lower value is used by the getAddress function, the upper value is used for setting the EEPROM size. Writing outside the maximum size will result in an error message. The following EEPROM sizes are predefined
Based on processor:
*EEPROMSizeATmega168 *EEPROMSizeATmega328 *EEPROMSizeATmega1280 *EEPROMSizeATmega32u4 *EEPROMSizeAT90USB1286 *EEPROMSizeMK20DX128Based on board:
*EEPROMSizeUno *EEPROMSizeUnoSMD *EEPROMSizeLilypad *EEPROMSizeDuemilanove *EEPROMSizeMega *EEPROMSizeDiecimila *EEPROMSizeNano *EEPROMSizeTeensy2 *EEPROMSizeLeonardo *EEPROMSizeMicro *EEPROMSizeYun *EEPROMSizeTeensy2pp *EEPROMSizeTeensy3
All of the read/write functions make sure the EEPROM is ready to be accessed. Since this may cause a delay of max 4ms, time-critical applications should first poll the EEPROM e. g. using the isReady function before attempting any actual I/O:
EEPROMEx is provided Copyright © 2013-2017 under LGPL License.