M24LR64E Class Reference

C++ API for the M24LR64E-based Grove NFC Tag. More...

Detailed Description

• ID: m24lr64e
• Name: Grove NFC Tag
• Category: other
• Manufacturer: seeed
• Link: http://www.seeedstudio.com/wiki/Grove_-_NFC_Tag
• Connection: i2c

Grove NFC tag is an 8KB electrically erasable programmable read-only memory (EEPROM) that can be written to or read from using I2C and NFC-equipped devices.

The user mode (default) allows read and write access to all 8KB of space, provided the sector security status (SSS) allows it. The root mode allows modification of the SSS data and other information, provided the proper password is submitted. The default password for a new tag is 0x00000000. See the datasheet for more details.

The Seeed Studio* wiki page for this device includes a link to an Android* application that can be used to also read and write the device via NFC, as well as set NFC passwords, which cannot be done via I2C.

        // Instantiate an M24LR64E on I2C bus 0
        upm_m24lr64e.M24LR64E nfcTag = new upm_m24lr64e.M24LR64E(0);

        // This example accesses the device in the 'user' (default) mode,
        // reads the last byte of data in the EEPROM, inverts it, writes
        // it back, and then re-reads it.

        // Read the last byte of the EEPROM area
        int addr = upm_m24lr64e.M24LR64E.EEPROM_I2C_LENGTH - 1;
        System.out.println("Address: " + addr);
        short read = nfcTag.readByte(addr);
        System.out.println("Read: " + read);

        // Now change it to it's opposite and write it
        read = (short) (~read & 0xff);
        nfcTag.writeByte(addr, read);
        System.out.println("Wrote: " + read);

        // Now read it back
        read = nfcTag.readByte(addr);
        System.out.println("Read: " + read);

Classes
class	AccessMode
class	M24LR64E_ADDR_T
class	SectorAccessRight
class	SectorSelectPassWd

Public Member Functions
synchronized void	delete ()
	M24LR64E (int bus, M24LR64E.AccessMode mode)
	M24LR64E (int bus)
boolean	submitPasswd (long passwd)
boolean	writePasswd (long passwd)
void	sectorProtectConfig (long sectorNumber, boolean protectEnable, M24LR64E.SectorAccessRight accessRight, M24LR64E.SectorSelectPassWd passwd)
void	clearSectorProtect ()
void	sectorWriteLockBit (long sectorNumber, boolean sockEnable)
short	getDSFID ()
short	getAFI ()
byte[]	getUID ()
long	getMemorySize ()
void	clearMemory ()
int	writeByte (long address, short data)
int	writeBytes (long address, byte[] buffer)
short	readByte (long address)
int	readBytes (long address, byte[] buffer)

Static Public Attributes
static final int	EEPROM_I2C_LENGTH = javaupm_m24lr64eJNI.M24LR64E_EEPROM_I2C_LENGTH_get()
static final int	PASSWORD_LENGTH = javaupm_m24lr64eJNI.M24LR64E_PASSWORD_LENGTH_get()
static final int	SECTOR_SECURITY_STATUS_BASE_ADDR = javaupm_m24lr64eJNI.M24LR64E_SECTOR_SECURITY_STATUS_BASE_ADDR_get()
static final short	LOCK_PROTECT_BIT = javaupm_m24lr64eJNI.M24LR64E_LOCK_PROTECT_BIT_get()
static final short	WRITE_READ_PROTECT_BIT = javaupm_m24lr64eJNI.M24LR64E_WRITE_READ_PROTECT_BIT_get()
static final short	PASSWORD_CTRL_BIT = javaupm_m24lr64eJNI.M24LR64E_PASSWORD_CTRL_BIT_get()
static final int	UID_LENGTH = javaupm_m24lr64eJNI.M24LR64E_UID_LENGTH_get()
static final long	I2C_WRITE_TIME = javaupm_m24lr64eJNI.M24LR64E_I2C_WRITE_TIME_get()

Constructor & Destructor Documentation

M24LR64E	(	int	bus,
		M24LR64E.AccessMode	mode
	)

M24LR64E constructor

Parameters

bus	I2C bus to use
mode	Access mode (user or root) to use

Member Function Documentation

void clearMemory

(

)

Sets all memory to 0, if permissions allow

short getAFI

(

)

Returns an application family identifier (AFI) Must be in the root mode.

Returns

AFI

short getDSFID

(

)

Returns a data storage family identifier (DSFID) Must be in the root mode.

Returns

DSFID

long getMemorySize

(

)

Returns the memory size Must be in the root mode.

Returns

Amount of memory present

byte [] getUID

(

)

Returns a unique ID. Must be in the root mode. Maintained to preserve compatibility with older code.

Returns

buf Buffer to hold the UID. Must be UID_LENGTH bytes.

short readByte

(

long

address

)

Reads a byte from the EEPROM

Parameters

address

Address to read from

Returns

data Value read

void sectorProtectConfig	(	long	sectorNumber,
		boolean	protectEnable,
		M24LR64E.SectorAccessRight	accessRight,
		M24LR64E.SectorSelectPassWd	passwd
	)

Sets a protection bit for a sector. Must be in the root mode

Parameters

sectorNumber	Sector whose protection you are modifying
protectEnable	True if you are enabling protection
accessRight	Access rights to set
passwd	Password number to enable, if any

void sectorWriteLockBit	(	long	sectorNumber,
		boolean	sockEnable
	)

Sets or clears a sector security status lock bit for a sector. Must be in the root mode.

Parameters

sectorNumber	Sector whose SSS you want to modify
sockEnable	True to set the bit, false to clear it

boolean submitPasswd

(

long

passwd

)

Submits an I2C access password

Parameters

passwd

4-byte access password

int writeByte	(	long	address,
		short	data
	)

Writes a byte to the EEPROM

Parameters

address	Address to write to
data	Data to write

boolean writePasswd

(

long

passwd

)

Writes a new I2C password

Parameters

passwd

4-byte access password

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The documentation for this class was generated from the following file:

• /var/lib/jenkins/workspace/upm-doc-stable/build-33/src/m24lr64e/M24LR64E.java