AT25M02.hpp

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#ifndef AT25M02_H
#define AT25M02_H
 
#include "Arduino.h"
#include "SPI.h"
 
enum Command
{
    READ_STATUS = 0x05,
    LOW_PWR_WRITE_POLL = 0x05,
    WRITE_ENABLE = 0x06,
    WRITE_DISABLE = 0x04,
    WRITE_STATUS = 0x01,
    READ = 0x03,
    WRITE_BYTE = 0x02,
    WRITE_PAGE = 0x02
};
class AT25M02
{
    public:
        AT25M02(){};
        void init();
 
        /*
         * Write from the given array to the memory. This data is
         * appended to the end of the queue.
         * Returns true if it successfully wrote all bytes.
         * Returns false if it could not write every byte without
         * overwriting existing data.
         */
        bool writeData(byte* bytes, uint32_t length);
 
        /*
         * Write the given number of bytes from the ram into the
         * destination array. These bytes are taken from the start of
         * the queue. Returns how many bytes were read.
         */
        int readData(byte* dest, uint32_t length);
 
        /*
         * Returns how many bytes are free and available to be written
         * to.
         */
        uint32_t freeBytes();
 
        /*
         * Returns the number of bytes currently being used.
         */
        uint32_t usedBytes();
 
        /*
         * Checks if the RAM chip is ready for a new command.
         */
        bool isReady();
 
    private:
        /*
         * Reads the status register and returns the register
         */
        byte readStatusReg();
 
        uint32_t usedMemoryBytes();
        uint32_t freeMemoryBytes();
        uint32_t usedBufferBytes();
        uint32_t freeBufferBytes();
 
        uint32_t readWriteBuffer(byte *dest, uint32_t length);
        uint32_t readMemory(byte *dest, uint32_t length);
 
        /*
         * Sets the Write Status Register
         */
        void setWRSR(byte val);
 
        /*
         * Waits until the write cycle is done.
         */
        void waitUntilReady();
 
        /*
         * Writes are page buffered.
         * Partial page reads are supported.
         * Start is inclusive, end is exclusive.
         */
        uint8_t write_buffer[256];
        uint32_t wb_end;
        uint32_t mem_start;
        uint32_t mem_end;
        bool ram_full;
 
        SPISettings spi_settings;
 
        /*
         * Just writes a page without caring about overwrite
         */
        void writePage(uint32_t addr, byte* bytes, uint32_t length);
 
        /*
         * Chips select low => enabled on this chip.
         */
        void csl();
 
        /*
         * Chip select high => disabled on this chip/
         */
        void csh();
 
        /*
         * Sends a command to the EEPROM.
         */
        void sendCommand(Command cmd);
 
        // Pin out information
        int chip_select_pin;
};
 
#endif