NFCT driver

group nrfx_nfct

Near Field Communication Tag (NFCT) peripheral driver.

Defines

NRFX_NFCT_NFCID1_SINGLE_SIZE

Length of single-size NFCID1.

NRFX_NFCT_NFCID1_DOUBLE_SIZE

Length of double-size NFCID1.

NRFX_NFCT_NFCID1_TRIPLE_SIZE

Length of triple-size NFCID1.

NRFX_NFCT_NFCID1_DEFAULT_LEN

Default length of NFC ID. */.

Typedefs

typedef void (*nrfx_nfct_handler_t)(nrfx_nfct_evt_t const *p_event)

Callback descriptor to pass events from the NFCT driver to the upper layer.

Note

NRFX_NFCT_EVT_FIELD_DETECTED and NRFX_NFCT_EVT_FIELD_LOST are generated only on field state transitions, i.e. there will be no multiple events of the same type (out of the 2 mentioned) coming in a row.

Param p_event:

[in] Pointer to the event descriptor.

Enums

enum nrfx_nfct_state_t

NFCT hardware states.

Values:

enumerator NRFX_NFCT_STATE_DISABLED

NFC Tag is disabled (no sensing of an external NFC field).

enumerator NRFX_NFCT_STATE_SENSING

NFC Tag is sensing whether there is an external NFC field.

enumerator NRFX_NFCT_STATE_ACTIVATED

NFC Tag is powered-up (see nrfx_nfct_active_state_t for possible substates).

enum nrfx_nfct_active_state_t

NFC tag states, when NFCT hardware is activated.

These states are substates of the NRFX_NFCT_STATE_ACTIVATED state.

Values:

enumerator NRFX_NFCT_ACTIVE_STATE_IDLE

NFC Tag is activated and idle (not selected by a reader).

enumerator NRFX_NFCT_ACTIVE_STATE_SLEEP

NFC Tag is sleeping.

enumerator NRFX_NFCT_ACTIVE_STATE_DEFAULT

NFC Tag is either sleeping or idle, depending on the previous state before being selected by a poller.

enum nrfx_nfct_evt_id_t

NFCT driver event types, passed to the upper-layer callback function provided during the initialization.

Values:

enumerator NRFX_NFCT_EVT_FIELD_DETECTED

External NFC field is detected.

enumerator NRFX_NFCT_EVT_FIELD_LOST

External NFC Field is lost.

enumerator NRFX_NFCT_EVT_SELECTED

Tag was selected by the poller.

enumerator NRFX_NFCT_EVT_RX_FRAMESTART

Data frame reception started.

enumerator NRFX_NFCT_EVT_RX_FRAMEEND

Data frame is received.

enumerator NRFX_NFCT_EVT_TX_FRAMESTART

Data frame transmission started.

enumerator NRFX_NFCT_EVT_TX_FRAMEEND

Data frame is transmitted.

enumerator NRFX_NFCT_EVT_ERROR

Error occurred in an NFC communication.

enum nrfx_nfct_error_t

NFCT timing-related error types.

Values:

enumerator NRFX_NFCT_ERROR_FRAMEDELAYTIMEOUT

No response frame was transmitted to the poller in the transmit window.

enumerator NRFX_NFCT_ERROR_NUM

Total number of possible errors.

enum nrfx_nfct_param_id_t

NFCT driver parameter types.

Values:

enumerator NRFX_NFCT_PARAM_ID_FDT

NFC-A Frame Delay Time parameter.

enumerator NRFX_NFCT_PARAM_ID_FDT_MIN

NFC-A Frame Delay Time Min parameter.

enumerator NRFX_NFCT_PARAM_ID_SEL_RES

Value of the ‘Protocol’ field in the NFC-A SEL_RES frame.

enumerator NRFX_NFCT_PARAM_ID_NFCID1

NFC-A NFCID1 setting (NFC tag identifier).

Functions

nrfx_err_t nrfx_nfct_init(nrfx_nfct_config_t const *p_config)

Function for initializing the NFCT driver.

Parameters:

  • p_config – [in] Pointer to the NFCT driver configuration structure.

Return values:

  • NRFX_SUCCESS – The NFCT driver was initialized successfully.

  • NRFX_ERROR_INVALID_STATE – The NFCT driver is already initialized.

  • NRFX_ERROR_FORBIDDEN – The NFCT antenna pads are not configured as antenna pins.

void nrfx_nfct_uninit(void)

Function for uninitializing the NFCT driver.

After uninitialization, the instance is in disabled state.

void nrfx_nfct_enable(void)

Function for starting the NFC subsystem.

After this function completes, NFC readers are able to detect the tag.

void nrfx_nfct_disable(void)

Function for disabling the NFCT driver.

After this function returns, NFC readers are no longer able to connect to the tag.

bool nrfx_nfct_field_check(void)

Function for checking whether the external NFC field is present in the range of the tag.

Return values:

  • true – The NFC field is present.

  • false – No NFC field is present.

nrfx_err_t nrfx_nfct_rx(nrfx_nfct_data_desc_t const *p_rx_data)

Function for preparing the NFCT driver for receiving an NFC frame.

Parameters:

  • p_rx_data – [in] Pointer to the RX buffer.

Return values:

  • NRFX_SUCCESS – The operation was successful.

  • NRFX_ERROR_INVALID_ADDR – Data buffer does not point to memory region reachable by EasyDMA.

nrfx_err_t nrfx_nfct_tx(nrfx_nfct_data_desc_t const *p_tx_data, nrf_nfct_frame_delay_mode_t delay_mode)

Function for transmitting an NFC frame.

Parameters:

  • p_tx_data – [in] Pointer to the TX buffer.

  • delay_mode – [in] Delay mode of the NFCT frame timer.

Return values:

  • NRFX_SUCCESS – The operation was successful.

  • NRFX_ERROR_INVALID_LENGTH – The TX buffer size is invalid.

  • NRFX_ERROR_BUSY – Driver is already transferring.

  • NRFX_ERROR_INVALID_ADDR – Data buffer does not point to memory region reachable by EasyDMA.

nrfx_err_t nrfx_nfct_bits_tx(nrfx_nfct_data_desc_t const *p_tx_data, nrf_nfct_frame_delay_mode_t delay_mode)

Function for transmitting an NFC frame with a specified number of bits.

Parameters:

  • p_tx_data – [in] Pointer to the TX buffer. Unlike in nrfx_nfct_tx, data_size is used as the number of bits to transmit, rather than bytes.

  • delay_mode – [in] Delay mode of the NFCT frame timer.

Return values:

  • NRFX_SUCCESS – The operation was successful.

  • NRFX_ERROR_INVALID_LENGTH – The TX buffer size is invalid.

  • NRFX_ERROR_BUSY – Driver is already transferring.

  • NRFX_ERROR_INVALID_ADDR – Data buffer does not point to memory region reachable by EasyDMA.

void nrfx_nfct_state_force(nrfx_nfct_state_t state)

Function for moving the NFCT to a new state.

Note

The HFCLK must be running before activating the NFCT with NRFX_NFCT_STATE_ACTIVATED.

Parameters:

  • state – [in] The required state.

void nrfx_nfct_init_substate_force(nrfx_nfct_active_state_t sub_state)

Function for moving the NFCT to a new initial substate within NRFX_NFCT_STATE_ACTIVATED.

Parameters:

  • sub_state – [in] The required substate.

nrfx_err_t nrfx_nfct_parameter_set(nrfx_nfct_param_t const *p_param)

Function for setting the NFC communication parameter.

Note

Parameter validation for length and acceptable values.

Parameters:

  • p_param – [in] Pointer to parameter descriptor.

Return values:

  • NRFX_SUCCESS – The operation was successful.

  • NRFX_ERROR_INVALID_PARAM – The parameter data is invalid.

nrfx_err_t nrfx_nfct_nfcid1_default_bytes_get(uint8_t *const p_nfcid1_buff, uint32_t nfcid1_buff_len)

Function for getting default bytes for NFCID1.

Note

This function cannot be used from the non-secure code because it requires access to FICR registers.

Parameters:

  • p_nfcid1_buff – [inout] In: empty buffer for data; Out: buffer with the NFCID1 default data. These values can be used to fill the Type 2 Tag Internal Bytes.

  • nfcid1_buff_len – [in] Length of the NFCID1 buffer.

Return values:
void nrfx_nfct_autocolres_enable(void)

Function for enabling the automatic collision resolution.

As defined by the NFC Forum Digital Protocol Technical Specification (and ISO 14443-3), the automatic collision resolution is implemented in the NFCT hardware. This function allows enabling and disabling this feature.

void nrfx_nfct_autocolres_disable(void)

Function for disabling the automatic collision resolution.

See also details in nrfx_nfct_autocolres_enable.

struct nrfx_nfct_nfcid1_t
#include <nrfx_nfct.h>

NFCID1 descriptor.

Public Members

uint8_t const *p_id

NFCID1 data.

uint8_t id_size

NFCID1 size.

struct nrfx_nfct_param_t
#include <nrfx_nfct.h>

NFCT driver parameter descriptor.

Public Members

nrfx_nfct_param_id_t id

Type of parameter.

uint32_t fdt

NFC-A Frame Delay Time. Filled when nrfx_nfct_param_t.id is NRFX_NFCT_PARAM_ID_FDT.

uint32_t fdt_min

NFC-A Frame Delay Time Min. Filled when nrfx_nfct_param_t.id is NRFX_NFCT_PARAM_ID_FDT_MIN.

uint8_t sel_res_protocol

NFC-A value of the ‘Protocol’ field in the SEL_RES frame. Filled when nrfx_nfct_param_t.id is NRFX_NFCT_PARAM_ID_SEL_RES.

nrfx_nfct_nfcid1_t nfcid1

NFC-A NFCID1 value (tag identifier). Filled when nrfx_nfct_param_t.id is NRFX_NFCT_PARAM_ID_NFCID1.

union nrfx_nfct_param_t.[anonymous] data

Union to store parameter data.

struct nrfx_nfct_data_desc_t
#include <nrfx_nfct.h>

NFCT driver RX/TX buffer descriptor.

Public Members

uint32_t data_size

RX/TX buffer size.

uint8_t const *p_data

RX/TX buffer.

struct nrfx_nfct_evt_rx_frameend_t
#include <nrfx_nfct.h>

Structure used to describe the NRFX_NFCT_EVT_RX_FRAMEEND event type.

Public Members

uint32_t rx_status

RX error status.

nrfx_nfct_data_desc_t rx_data

RX buffer.

struct nrfx_nfct_evt_tx_framestart_t
#include <nrfx_nfct.h>

Structure used to describe the NRFX_NFCT_EVT_TX_FRAMESTART event type.

Public Members

nrfx_nfct_data_desc_t tx_data

TX buffer.

struct nrfx_nfct_evt_error_t
#include <nrfx_nfct.h>

Structure used to describe the NRFX_NFCT_EVT_ERROR event type.

Public Members

nrfx_nfct_error_t reason

Reason for error.

struct nrfx_nfct_evt_t
#include <nrfx_nfct.h>

NFCT driver event.

Public Members

nrfx_nfct_evt_id_t evt_id

Type of event.

nrfx_nfct_evt_rx_frameend_t rx_frameend

End of the RX frame data. Filled when nrfx_nfct_evt_t.evt_id is NRFX_NFCT_EVT_RX_FRAMEEND.

nrfx_nfct_evt_tx_framestart_t tx_framestart

Start of the TX frame data. Filled when nrfx_nfct_evt_t.evt_id is NRFX_NFCT_EVT_TX_FRAMESTART.

nrfx_nfct_evt_error_t error

Error data. Filled when nrfx_nfct_evt_t.evt_id is NRFX_NFCT_EVT_ERROR.

union nrfx_nfct_evt_t.[anonymous] params

Union to store event data.

struct nrfx_nfct_config_t
#include <nrfx_nfct.h>

NFCT driver configuration structure.

Public Members

uint32_t rxtx_int_mask

Mask for enabling RX/TX events. Indicate which events must be forwarded to the upper layer by using nrfx_nfct_evt_id_t. By default, no events are enabled. */.

nrfx_nfct_handler_t cb

Callback.

uint8_t irq_priority

Interrupt priority.