Added in API level 10

MifareUltralight


class MifareUltralight : TagTechnology
kotlin.Any
   ↳ android.nfc.tech.MifareUltralight

Provides access to MIFARE Ultralight properties and I/O operations on a Tag.

Acquire a MifareUltralight object using get.

MIFARE Ultralight compatible tags have 4 byte pages PAGE_SIZE. The primary operations on an Ultralight tag are readPages and writePage.

The original MIFARE Ultralight consists of a 64 byte EEPROM. The first 4 pages are for the OTP area, manufacturer data, and locking bits. They are readable and some bits are writable. The final 12 pages are the user read/write area. For more information see the NXP data sheet MF0ICU1.

The MIFARE Ultralight C consists of a 192 byte EEPROM. The first 4 pages are for OTP, manufacturer data, and locking bits. The next 36 pages are the user read/write area. The next 4 pages are additional locking bits, counters and authentication configuration and are readable. The final 4 pages are for the authentication key and are not readable. For more information see the NXP data sheet MF0ICU2.

Implementation of this class on a Android NFC device is optional. If it is not implemented, then MifareUltralight will never be enumerated in Tag#getTechList. If it is enumerated, then all MifareUltralight I/O operations will be supported. In either case, NfcA will also be enumerated on the tag, because all MIFARE Ultralight tags are also NfcA tags.

Note: Methods that perform I/O operations require the android.Manifest.permission#NFC permission.

Summary

Constants
static Int

Size of a MIFARE Ultralight page in bytes

static Int

A MIFARE Ultralight tag

static Int

A MIFARE Ultralight C tag

static Int

A MIFARE Ultralight compatible tag of unknown type

Public methods
Unit

Unit

static MifareUltralight!
get(tag: Tag!)

Get an instance of MifareUltralight for the given tag.

Int

Return the maximum number of bytes that can be sent with transceive.

Tag!

Int

Get the current transceive timeout in milliseconds.

Int

Return the MIFARE Ultralight type of the tag.

Boolean

ByteArray!
readPages(pageOffset: Int)

Read 4 pages (16 bytes).

Unit
setTimeout(timeout: Int)

Set the transceive timeout in milliseconds.

ByteArray!

Send raw NfcA data to a tag and receive the response.

Unit
writePage(pageOffset: Int, data: ByteArray!)

Write 1 page (4 bytes).

Constants

PAGE_SIZE

Added in API level 10
static val PAGE_SIZE: Int

Size of a MIFARE Ultralight page in bytes

Value: 4

TYPE_ULTRALIGHT

Added in API level 10
static val TYPE_ULTRALIGHT: Int

A MIFARE Ultralight tag

Value: 1

TYPE_ULTRALIGHT_C

Added in API level 10
static val TYPE_ULTRALIGHT_C: Int

A MIFARE Ultralight C tag

Value: 2

TYPE_UNKNOWN

Added in API level 10
static val TYPE_UNKNOWN: Int

A MIFARE Ultralight compatible tag of unknown type

Value: -1

Public methods

close

Added in API level 10
fun close(): Unit
Exceptions
java.lang.Exception if this resource cannot be closed
java.io.IOException if an I/O error occurs
java.lang.SecurityException if the tag object is reused after the tag has left the field

connect

Added in API level 10
fun connect(): Unit
Exceptions
TagLostException if the tag leaves the field
java.io.IOException if there is an I/O failure, or connect is canceled
java.lang.SecurityException if the tag object is reused after the tag has left the field

get

Added in API level 10
static fun get(tag: Tag!): MifareUltralight!

Get an instance of MifareUltralight for the given tag.

Returns null if MifareUltralight was not enumerated in Tag#getTechList - this indicates the tag is not MIFARE Ultralight compatible, or that this Android device does not implement MIFARE Ultralight.

Does not cause any RF activity and does not block.

Parameters
tag Tag!: an MIFARE Ultralight compatible tag
Return
MifareUltralight! MIFARE Ultralight object

getMaxTransceiveLength

Added in API level 14
fun getMaxTransceiveLength(): Int

Return the maximum number of bytes that can be sent with transceive.

Return
Int the maximum number of bytes that can be sent with transceive.

getTag

Added in API level 10
fun getTag(): Tag!
Return
Tag! the Tag backing this TagTechnology object.

getTimeout

Added in API level 14
fun getTimeout(): Int

Get the current transceive timeout in milliseconds.

Requires the android.Manifest.permission#NFC permission.

Return
Int timeout value in milliseconds
Exceptions
java.lang.SecurityException if the tag object is reused after the tag has left the field

getType

Added in API level 10
fun getType(): Int

Return the MIFARE Ultralight type of the tag.

One of TYPE_ULTRALIGHT or TYPE_ULTRALIGHT_C or TYPE_UNKNOWN.

Depending on how the tag has been formatted, it can be impossible to accurately classify between original MIFARE Ultralight and Ultralight C. So treat this method as a hint.

Does not cause any RF activity and does not block.

Return
Int the type

isConnected

Added in API level 10
fun isConnected(): Boolean
Return
Boolean true if I/O operations should be possible

readPages

Added in API level 10
fun readPages(pageOffset: Int): ByteArray!

Read 4 pages (16 bytes).

The MIFARE Ultralight protocol always reads 4 pages at a time, to reduce the number of commands required to read an entire tag.

If a read spans past the last readable block, then the tag will return pages that have been wrapped back to the first blocks. MIFARE Ultralight tags have readable blocks 0x00 through 0x0F. So a read to block offset 0x0E would return blocks 0x0E, 0x0F, 0x00, 0x01. MIFARE Ultralight C tags have readable blocks 0x00 through 0x2B. So a read to block 0x2A would return blocks 0x2A, 0x2B, 0x00, 0x01.

This is an I/O operation and will block until complete. It must not be called from the main application thread. A blocked call will be canceled with IOException if #close is called from another thread.

Requires the android.Manifest.permission#NFC permission.

Parameters
pageOffset Int: index of first page to read, starting from 0
Return
ByteArray! 4 pages (16 bytes)
Exceptions
android.nfc.TagLostException if the tag leaves the field
java.io.IOException if there is an I/O failure, or the operation is canceled

setTimeout

Added in API level 14
fun setTimeout(timeout: Int): Unit

Set the transceive timeout in milliseconds.

The timeout only applies to transceive on this object, and is reset to a default value when #close is called.

Setting a longer timeout may be useful when performing transactions that require a long processing time on the tag such as key generation.

Requires the android.Manifest.permission#NFC permission.

Parameters
timeout Int: timeout value in milliseconds
Exceptions
java.lang.SecurityException if the tag object is reused after the tag has left the field

transceive

Added in API level 10
fun transceive(data: ByteArray!): ByteArray!

Send raw NfcA data to a tag and receive the response.

This is equivalent to connecting to this tag via NfcA and calling NfcA#transceive. Note that all MIFARE Classic tags are based on NfcA technology.

Use getMaxTransceiveLength to retrieve the maximum number of bytes that can be sent with transceive.

This is an I/O operation and will block until complete. It must not be called from the main application thread. A blocked call will be canceled with IOException if #close is called from another thread.

Requires the android.Manifest.permission#NFC permission.

writePage

Added in API level 10
fun writePage(
    pageOffset: Int,
    data: ByteArray!
): Unit

Write 1 page (4 bytes).

The MIFARE Ultralight protocol always writes 1 page at a time, to minimize EEPROM write cycles.

This is an I/O operation and will block until complete. It must not be called from the main application thread. A blocked call will be canceled with IOException if #close is called from another thread.

Requires the android.Manifest.permission#NFC permission.

Parameters
pageOffset Int: index of page to write, starting from 0
data ByteArray!: 4 bytes to write
Exceptions
android.nfc.TagLostException if the tag leaves the field
java.io.IOException if there is an I/O failure, or the operation is canceled