openHAB - NFC Bricklet¶

Scan For Tags¶

Download (ExampleScanForTags.rules)

 1// For this example create an item linked to the state channel of your NFC Bricklet.
 2
 3import java.util.List;
 4import java.util.stream.Collectors;
 5
 6val READER_STATE_IDLE = 128
 7val READER_STATE_REQUEST_TAG_ID_READY = 130
 8val READER_STATE_REQUEST_TAG_ID_ERROR = 194
 9
10rule "NFC"
11when
12    // Change XYZ_State to the created item name
13    Item XYZ_State changed
14then
15    val stateVal = newState as Number
16    val int state = stateVal.intValue
17    
18    // Change XYZ to the UID of your NFC Bricklet
19    val nfc = getActions("tinkerforge", "tinkerforge:brickletnfc:XYZ")
20
21    if (state == READER_STATE_IDLE || state == READER_STATE_REQUEST_TAG_ID_ERROR) {
22        nfc.brickletNFCReaderRequestTagID()
23    } else if (state == READER_STATE_REQUEST_TAG_ID_READY) {
24        logInfo("Example", "tag id ready")
25        
26        val ret = nfc.brickletNFCReaderGetTagID()
27        
28        val tagType = ret.get("tagType")
29        val tagID = ret.get("tagID") as List<Integer>
30        val tag = String.join(" ", tagID.stream().map([i | String.format("0x%02X", i)]).collect(Collectors.toList()));
31        
32        logInfo("Example", "tag id:" + tag)
33        
34        // Read tag ID again in one second.
35        createTimer(now.plusSeconds(1), [|nfc.brickletNFCReaderRequestTagID()])
36    }
37end

Basic Actions¶

brickletNFCGetMode()¶

Return Map:	mode – Type: int, Range: See constants, Default: 0

Returns the mode as set by the thing configuration.

The following constants are available for this function:

For mode:

• val MODE_OFF = 0

• val MODE_CARDEMU = 1

• val MODE_P2P = 2

• val MODE_READER = 3

• val MODE_SIMPLE = 4

brickletNFCReaderRequestTagID()¶

After you call ReaderRequestTagID() the NFC Bricklet will try to read the tag ID from the tag. After this process is done the state will change. You can either register the State channel or you can poll State to find out about the state change.

If the state changes to ReaderRequestTagIDError it means that either there was no tag present or that the tag has an incompatible type. If the state changes to ReaderRequestTagIDReady it means that a compatible tag was found and that the tag ID has been saved. You can now read out the tag ID by calling ReaderGetTagID().

If two tags are in the proximity of the NFC Bricklet, this function will cycle through the tags. To select a specific tag you have to call ReaderRequestTagID() until the correct tag ID is found.

In case of any ReaderError state the selection is lost and you have to start again by calling ReaderRequestTagID().

brickletNFCReaderGetTagID()¶

Return Map:	tagType – Type: int, Range: See constants tagID – Type: int[], Length: variable, Range: [0 to 255]

Returns the tag type and the tag ID. This function can only be called if the NFC Bricklet is currently in one of the ReaderReady states. The returned tag ID is the tag ID that was saved through the last call of ReaderRequestTagID().

To get the tag ID of a tag the approach is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to ReaderRequestTagIDReady (see State or State channel)

3. Call ReaderGetTagID()

The following constants are available for this function:

For tagType:

• val TAG_TYPE_MIFARE_CLASSIC = 0

• val TAG_TYPE_TYPE1 = 1

• val TAG_TYPE_TYPE2 = 2

• val TAG_TYPE_TYPE3 = 3

• val TAG_TYPE_TYPE4 = 4

• val TAG_TYPE_TYPE5 = 5

brickletNFCReaderGetState()¶

Return Map:	state – Type: int, Range: See constants idle – Type: boolean

Returns the current reader state of the NFC Bricklet.

On startup the Bricklet will be in the ReaderInitialization state. The initialization will only take about 20ms. After that it changes to ReaderIdle.

The Bricklet is also reinitialized if the mode is changed, see the thing configuration.

The functions of this Bricklet can be called in the ReaderIdle state and all of the ReaderReady and ReaderError states.

Example: If you call ReaderRequestPage(), the state will change to ReaderRequestPage until the reading of the page is finished. Then it will change to either ReaderRequestPageReady if it worked or to ReaderRequestPageError if it didn't. If the request worked you can get the page by calling ReaderReadPage().

The same approach is used analogously for the other API functions.

The following constants are available for this function:

For state:

• val READER_STATE_INITIALIZATION = 0

• val READER_STATE_IDLE = 128

• val READER_STATE_ERROR = 192

• val READER_STATE_REQUEST_TAG_ID = 2

• val READER_STATE_REQUEST_TAG_ID_READY = 130

• val READER_STATE_REQUEST_TAG_ID_ERROR = 194

• val READER_STATE_AUTHENTICATE_MIFARE_CLASSIC_PAGE = 3

• val READER_STATE_AUTHENTICATE_MIFARE_CLASSIC_PAGE_READY = 131

• val READER_STATE_AUTHENTICATE_MIFARE_CLASSIC_PAGE_ERROR = 195

• val READER_STATE_WRITE_PAGE = 4

• val READER_STATE_WRITE_PAGE_READY = 132

• val READER_STATE_WRITE_PAGE_ERROR = 196

• val READER_STATE_REQUEST_PAGE = 5

• val READER_STATE_REQUEST_PAGE_READY = 133

• val READER_STATE_REQUEST_PAGE_ERROR = 197

• val READER_STATE_WRITE_NDEF = 6

• val READER_STATE_WRITE_NDEF_READY = 134

• val READER_STATE_WRITE_NDEF_ERROR = 198

• val READER_STATE_REQUEST_NDEF = 7

• val READER_STATE_REQUEST_NDEF_READY = 135

• val READER_STATE_REQUEST_NDEF_ERROR = 199

brickletNFCReaderWriteNDEF(int[] ndef)¶

Parameters:	ndef – Type: int[], Length: variable, Range: [0 to 255]

Writes NDEF formated data.

This function currently supports NFC Forum Type 2, 4, 5 and Mifare Classic.

The general approach for writing a NDEF message is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to ReaderRequestTagIDReady (see State or State channel)

3. If looking for a specific tag then call ReaderGetTagID() and check if the expected tag was found, if it was not found got back to step 1

4. Call ReaderWriteNDEF() with the NDEF message that you want to write

5. Wait for state to change to ReaderWriteNDEFReady (see State or State channel)

brickletNFCReaderRequestNDEF()¶

Reads NDEF formated data from a tag.

This function currently supports NFC Forum Type 1, 2, 3, 4, 5 and Mifare Classic.

The general approach for reading a NDEF message is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to RequestTagIDReady (see State or State channel)

3. If looking for a specific tag then call ReaderGetTagID() and check if the expected tag was found, if it was not found got back to step 1

4. Call ReaderRequestNDEF()

5. Wait for state to change to ReaderRequestNDEFReady (see State or State channel)

6. Call ReaderReadNDEF() to retrieve the NDEF message from the buffer

brickletNFCReaderReadNDEF()¶

Return Map:	ndef – Type: int[], Length: variable, Range: [0 to 255]

Returns the NDEF data from an internal buffer. To fill the buffer with a NDEF message you have to call ReaderRequestNDEF() beforehand.

brickletNFCReaderAuthenticateMifareClassicPage(int page, int keyNumber, int[] key)¶

Parameters:	page – Type: int, Range: [0 to 216 - 1] keyNumber – Type: int, Range: See constants key – Type: int[], Length: 6, Range: [0 to 255]

Mifare Classic tags use authentication. If you want to read from or write to a Mifare Classic page you have to authenticate it beforehand. Each page can be authenticated with two keys: A (key_number = 0) and B (key_number = 1). A new Mifare Classic tag that has not yet been written to can be accessed with key A and the default key [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF].

The approach to read or write a Mifare Classic page is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to ReaderRequestTagIDReady (see State or State channel)

3. If looking for a specific tag then call ReaderGetTagID() and check if the expected tag was found, if it was not found got back to step 1

4. Call ReaderAuthenticateMifareClassicPage() with page and key for the page

5. Wait for state to change to ReaderAuthenticatingMifareClassicPageReady (see State or State channel)

6. Call ReaderRequestPage() or ReaderWritePage() to read/write page

The authentication will always work for one whole sector (4 pages).

The following constants are available for this function:

For keyNumber:

• val KEY_A = 0

• val KEY_B = 1

brickletNFCReaderWritePage(int page, int[] data)¶

Parameters:	page – Type: int, Range: See constants data – Type: int[], Length: variable, Range: [0 to 255]

Writes a maximum of 8192 bytes starting from the given page. How many pages are written depends on the tag type. The page sizes are as follows:

• Mifare Classic page size: 16 byte

• NFC Forum Type 1 page size: 8 byte

• NFC Forum Type 2 page size: 4 byte

• NFC Forum Type 3 page size: 16 byte

• NFC Forum Type 4: No pages, page = file selection (CC or NDEF, see below)

• NFC Forum Type 5 page size: 4 byte

The general approach for writing to a tag is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to ReaderRequestTagIDReady (see State or State channel)

3. If looking for a specific tag then call ReaderGetTagID() and check if the expected tag was found, if it was not found got back to step 1

4. Call ReaderWritePage() with page number and data

5. Wait for state to change to ReaderWritePageReady (see State or State channel)

If you use a Mifare Classic tag you have to authenticate a page before you can write to it. See ReaderAuthenticateMifareClassicPage().

NFC Forum Type 4 tags are not organized into pages but different files. We currently support two files: Capability Container file (CC) and NDEF file.

Choose CC by setting page to 3 or NDEF by setting page to 4.

The following constants are available for this function:

For page:

• val READER_WRITE_TYPE4_CAPABILITY_CONTAINER = 3

• val READER_WRITE_TYPE4_NDEF = 4

brickletNFCReaderRequestPage(int page, int length)¶

Parameters:	page – Type: int, Range: See constants length – Type: int, Range: [0 to 213]

Reads a maximum of 8192 bytes starting from the given page and stores them into a buffer. The buffer can then be read out with ReaderReadPage(). How many pages are read depends on the tag type. The page sizes are as follows:

• Mifare Classic page size: 16 byte

• NFC Forum Type 1 page size: 8 byte

• NFC Forum Type 2 page size: 4 byte

• NFC Forum Type 3 page size: 16 byte

• NFC Forum Type 4: No pages, page = file selection (CC or NDEF, see below)

• NFC Forum Type 5 page size: 4 byte

The general approach for reading a tag is as follows:

1. Call ReaderRequestTagID()

2. Wait for state to change to RequestTagIDReady (see State or State channel)

3. If looking for a specific tag then call ReaderGetTagID() and check if the expected tag was found, if it was not found got back to step 1

4. Call ReaderRequestPage() with page number

5. Wait for state to change to ReaderRequestPageReady (see State or State channel)

6. Call ReaderReadPage() to retrieve the page from the buffer

If you use a Mifare Classic tag you have to authenticate a page before you can read it. See ReaderAuthenticateMifareClassicPage().

NFC Forum Type 4 tags are not organized into pages but different files. We currently support two files: Capability Container file (CC) and NDEF file.

Choose CC by setting page to 3 or NDEF by setting page to 4.

The following constants are available for this function:

For page:

• val READER_REQUEST_TYPE4_CAPABILITY_CONTAINER = 3

• val READER_REQUEST_TYPE4_NDEF = 4

brickletNFCReaderReadPage()¶

Return Map:	data – Type: int[], Length: variable, Range: [0 to 255]

Returns the page data from an internal buffer. To fill the buffer with specific pages you have to call ReaderRequestPage() beforehand.

brickletNFCCardemuGetState()¶

Return Map:	state – Type: int, Range: See constants idle – Type: boolean

Returns the current cardemu state of the NFC Bricklet.

On startup the Bricklet will be in the CardemuInitialization state. The initialization will only take about 20ms. After that it changes to CardemuIdle.

The Bricklet is also reinitialized if the mode is changed, see the thing configuration.

The functions of this Bricklet can be called in the CardemuIdle state and all of the CardemuReady and CardemuError states.

Example: If you call CardemuStartDiscovery(), the state will change to CardemuDiscover until the discovery is finished. Then it will change to either CardemuDiscoverReady if it worked or to CardemuDiscoverError if it didn't.

The same approach is used analogously for the other API functions.

The following constants are available for this function:

For state:

• val CARDEMU_STATE_INITIALIZATION = 0

• val CARDEMU_STATE_IDLE = 128

• val CARDEMU_STATE_ERROR = 192

• val CARDEMU_STATE_DISCOVER = 2

• val CARDEMU_STATE_DISCOVER_READY = 130

• val CARDEMU_STATE_DISCOVER_ERROR = 194

• val CARDEMU_STATE_TRANSFER_NDEF = 3

• val CARDEMU_STATE_TRANSFER_NDEF_READY = 131

• val CARDEMU_STATE_TRANSFER_NDEF_ERROR = 195

brickletNFCCardemuStartDiscovery()¶

Starts the discovery process. If you call this function while a NFC reader device is near to the NFC Bricklet the state will change from CardemuDiscovery to CardemuDiscoveryReady.

If no NFC reader device can be found or if there is an error during discovery the cardemu state will change to CardemuDiscoveryError. In this case you have to restart the discovery process.

If the cardemu state changes to CardemuDiscoveryReady you can start the NDEF message transfer with CardemuWriteNDEF() and CardemuStartTransfer().

brickletNFCCardemuWriteNDEF(int[] ndef)¶

Parameters:	ndef – Type: int[], Length: variable, Range: [0 to 255]

Writes the NDEF message that is to be transferred to the NFC peer.

The maximum supported NDEF message size in Cardemu mode is 255 byte.

You can call this function at any time in Cardemu mode. The internal buffer will not be overwritten until you call this function again or change the mode.

brickletNFCCardemuStartTransfer(int transfer)¶

Parameters:	transfer – Type: int, Range: See constants

You can start the transfer of a NDEF message if the cardemu state is CardemuDiscoveryReady.

Before you call this function to start a write transfer, the NDEF message that is to be transferred has to be written via CardemuWriteNDEF() first.

After you call this function the state will change to CardemuTransferNDEF. It will change to CardemuTransferNDEFReady if the transfer was successful or CardemuTransferNDEFError if it wasn't.

The following constants are available for this function:

For transfer:

• val CARDEMU_TRANSFER_ABORT = 0

• val CARDEMU_TRANSFER_WRITE = 1

brickletNFCP2PGetState()¶

Return Map:	state – Type: int, Range: See constants idle – Type: boolean

Returns the current P2P state of the NFC Bricklet.

On startup the Bricklet will be in the P2PInitialization state. The initialization will only take about 20ms. After that it changes to P2PIdle.

The Bricklet is also reinitialized if the mode is changed, see the thing configuration.

The functions of this Bricklet can be called in the P2PIdle state and all of the P2PReady and P2PError states.

Example: If you call P2PStartDiscovery(), the state will change to P2PDiscover until the discovery is finished. Then it will change to either P2PDiscoverReady* if it worked or to P2PDiscoverError if it didn't.

The same approach is used analogously for the other API functions.

The following constants are available for this function:

For state:

• val P2P_STATE_INITIALIZATION = 0

• val P2P_STATE_IDLE = 128

• val P2P_STATE_ERROR = 192

• val P2P_STATE_DISCOVER = 2

• val P2P_STATE_DISCOVER_READY = 130

• val P2P_STATE_DISCOVER_ERROR = 194

• val P2P_STATE_TRANSFER_NDEF = 3

• val P2P_STATE_TRANSFER_NDEF_READY = 131

• val P2P_STATE_TRANSFER_NDEF_ERROR = 195

brickletNFCP2PStartDiscovery()¶

Starts the discovery process. If you call this function while another NFC P2P enabled device is near to the NFC Bricklet the state will change from P2PDiscovery to P2PDiscoveryReady.

If no NFC P2P enabled device can be found or if there is an error during discovery the P2P state will change to P2PDiscoveryError. In this case you have to restart the discovery process.

If the P2P state changes to P2PDiscoveryReady you can start the NDEF message transfer with P2PStartTransfer().

brickletNFCP2PWriteNDEF(int[] ndef)¶

Parameters:	ndef – Type: int[], Length: variable, Range: [0 to 255]

Writes the NDEF message that is to be transferred to the NFC peer.

The maximum supported NDEF message size for P2P transfer is 255 byte.

You can call this function at any time in P2P mode. The internal buffer will not be overwritten until you call this function again, change the mode or use P2P to read an NDEF messages.

brickletNFCP2PStartTransfer(int transfer)¶

Parameters:	transfer – Type: int, Range: See constants

You can start the transfer of a NDEF message if the P2P state is P2PDiscoveryReady.

Before you call this function to start a write transfer, the NDEF message that is to be transferred has to be written via P2PWriteNDEF() first.

After you call this function the P2P state will change to P2PTransferNDEF. It will change to P2PTransferNDEFReady if the transfer was successfull or P2PTransferNDEFError if it wasn't.

If you started a write transfer you are now done. If you started a read transfer you can now use P2PReadNDEF() to read the NDEF message that was written by the NFC peer.

The following constants are available for this function:

For transfer:

• val P2P_TRANSFER_ABORT = 0

• val P2P_TRANSFER_WRITE = 1

• val P2P_TRANSFER_READ = 2

brickletNFCP2PReadNDEF()¶

Return Map:	ndef – Type: int[], Length: variable, Range: [0 to 255]

Returns the NDEF message that was written by a NFC peer in NFC P2P mode.

The NDEF message is ready if you called P2PStartTransfer() with a read transfer and the P2P state changed to P2PTransferNDEFReady.

Advanced Actions¶

brickletNFCGetChipTemperature()¶

Return Map:	temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

brickletNFCGetStatusLEDConfig()¶

Return Map:	config – Type: int, Range: See constants, Default: 3

Returns the configuration as set by the thing configuration

The following constants are available for this function:

For config:

• val STATUS_LED_CONFIG_OFF = 0

• val STATUS_LED_CONFIG_ON = 1

• val STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2

• val STATUS_LED_CONFIG_SHOW_STATUS = 3

brickletNFCGetSPITFPErrorCount()¶

Return Map:	errorCountAckChecksum – Type: long, Range: [0 to 232 - 1] errorCountMessageChecksum – Type: long, Range: [0 to 232 - 1] errorCountFrame – Type: long, Range: [0 to 232 - 1] errorCountOverflow – Type: long, Range: [0 to 232 - 1]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

• ACK checksum errors,

• message checksum errors,

• framing errors and

• overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

brickletNFCReset()¶

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

brickletNFCGetIdentity()¶

Return Map:

uid – Type: String, Length: up to 8 connectedUid – Type: String, Length: up to 8 position – Type: char, Range: ['a' to 'h', 'z'] hardwareVersion – Type: short[], Length: 3 0: major – Type: short, Range: [0 to 255] 1: minor – Type: short, Range: [0 to 255] 2: revision – Type: short, Range: [0 to 255] firmwareVersion – Type: short[], Length: 3 0: major – Type: short, Range: [0 to 255] 1: minor – Type: short, Range: [0 to 255] 2: revision – Type: short, Range: [0 to 255] deviceIdentifier – Type: int, Range: [0 to 216 - 1]

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. 

Internal Actions¶

brickletNFCReadUID()¶

Return Map:	uid – Type: long, Range: [0 to 232 - 1]

Returns the current UID as an integer. Encode as Base58 to get the usual string version.