Low-level PN532 driver (SPI + I²C, ESP-IDF). More...

Classes
struct	pn532_config_t
	Compile-time configuration passed to pn532_init. More...
struct	pn532_t
	Opaque-like runtime state for a single PN532 instance. More...

Macros
#define	PN532_MIFARE_ISO14443A (0x00U)
	Baud-rate selector for ISO 14443-A (Mifare) cards passed to pn532_read_passive_target_id.
#define	PN532_MAX_APDU_LEN (252U)
	Maximum APDU payload length accepted by pn532_send_apdu.
#define	PN532_I2C_ADDRESS (0x24U)
	7-bit I²C slave address of the PN532 (fixed in hardware).

Enumerations
enum	pn532_transport_t { PN532_TRANSPORT_SPI , PN532_TRANSPORT_I2C }
	Physical bus used to communicate with the PN532. More...

Functions
esp_err_t	pn532_init (pn532_t dev, const pn532_config_t config)
	Initialise the PN532 and bring it to a ready state.
uint32_t	pn532_get_firmware_version (pn532_t *dev)
	Query the PN532 firmware version.
bool	pn532_sam_config (pn532_t *dev)
	Configure the PN532's Security Access Module (SAM).
uint32_t	pn532_read_passive_target_id (pn532_t *dev, uint8_t cardbaudrate)
	Scan for a passive ISO 14443-A card and return its UID.
bool	pn532_send_apdu (pn532_t dev, const uint8_t apdu, uint8_t apdu_len, uint8_t response, uint16_t response_len)
	Exchange a single ISO-DEP APDU with the currently selected card.
bool	pn532_release_target (pn532_t *dev)
	Release the currently selected NFC target.

Detailed Description

Low-level PN532 driver (SPI + I²C, ESP-IDF).

Macro Definition Documentation

◆ PN532_I2C_ADDRESS

#define PN532_I2C_ADDRESS (0x24U)

7-bit I²C slave address of the PN532 (fixed in hardware).

Definition at line 63 of file pn532.h.

Referenced by pn532_init_i2c().

◆ PN532_MAX_APDU_LEN

#define PN532_MAX_APDU_LEN (252U)

Maximum APDU payload length accepted by pn532_send_apdu.

Constrained so that the PN532 InDataExchange frame LEN field (8-bit) never overflows: cmd_total_len = apdu_len + 2 ≤ 254, frame_len = 255.

Definition at line 60 of file pn532.h.

Referenced by pn532_send_apdu().

◆ PN532_MIFARE_ISO14443A

#define PN532_MIFARE_ISO14443A (0x00U)

Baud-rate selector for ISO 14443-A (Mifare) cards passed to pn532_read_passive_target_id.

Definition at line 54 of file pn532.h.

Referenced by PN532Adapter::inListPassiveTarget(), and Pn532NfcTransport::inListPassiveTarget().

Enumeration Type Documentation

◆ pn532_transport_t

enum pn532_transport_t

Physical bus used to communicate with the PN532.

Value	Bus	Typical use
`PN532_TRANSPORT_SPI`	SPI	ESP32-S3 dev kit + Keyestudio breakout
`PN532_TRANSPORT_I2C`	I²C	Cheap Yellow Display (CN1 connector)

Enumerator
PN532_TRANSPORT_SPI	SPI master via ESP-IDF `spi_master` driver.
PN532_TRANSPORT_I2C	I²C master via ESP-IDF v5.x `i2c_master` driver.

Definition at line 76 of file pn532.h.

Function Documentation

◆ pn532_get_firmware_version()

uint32_t pn532_get_firmware_version ( pn532_t * dev )

Query the PN532 firmware version.

Sends the GetFirmwareVersion command (0x02) and reads the response. Also serves as a FIFO-drain step after init to prevent stale bytes from confusing subsequent command sequences.

Parameters

[in] dev Initialised device handle.

Returns: Packed 32-bit version word: (IC << 24) | (Ver << 16) | (Rev << 8) | Support, or 0 on communication failure.

See also: pn532_init

Definition at line 718 of file pn532.c.

References pn532_buffer_equal(), PN532_BYTE_SHIFT_BITS, PN532_CMD_TIMEOUT_MS, PN532_FIRMWARE_CMD_LEN, PN532_FIRMWARE_HDR_LEN, PN532_FIRMWARE_RESP_LEN, PN532_FIRMWAREVERSION, PN532_FW_IC_OFFSET, PN532_FW_REV_OFFSET, PN532_FW_SUPPORT_OFFSET, PN532_FW_VER_OFFSET, PN532_LOG_TAG, pn532_response_fw, read_data(), and send_command_check_ack().

Referenced by pn532_init(), PN532Adapter::printFirmwareVersion(), and Pn532NfcTransport::printFirmwareVersion().

◆ pn532_init()

esp_err_t pn532_init	(	pn532_t *	dev,
		const pn532_config_t *	config )

Initialise the PN532 and bring it to a ready state.

Performs the full transport-specific bring-up:

SPI: configures the SPI device, runs the wake-up byte sequence, sends a sacrificial pn532_sam_config (absorbs the post-power-on latency), then confirms readiness with pn532_get_firmware_version.
I²C: configures the I²C bus and device, sends two SAMConfig frames to recover from Soft-Power-Down if the PN532 was already powered, then confirms readiness with pn532_get_firmware_version.

Parameters

[out]	dev	Device state structure to populate. Must remain valid for the lifetime of all subsequent calls on this device.
[in]	config	Transport and pin configuration. Caller may free or reuse this after `pn532_init` returns.

Returns: ESP_OK on success, an esp_err_t error code otherwise.

Note: The return value of the internal firmware-version and sacrificial SAMConfig calls is intentionally ignored; they are used purely for timing and FIFO-drain purposes.

Examples: BasicUsage/main/main.cpp, Connect/main/main.cpp, Sign/main/main.cpp, UsdcSigning/main/main.cpp, and VerifyPin/main/main.cpp.

Definition at line 657 of file pn532.c.

References pn532_get_firmware_version(), pn532_init_i2c(), pn532_init_spi(), PN532_LOG_TAG, pn532_sam_config(), PN532_SYNC_DELAY_MS, PN532_TRANSPORT_I2C, pn532_config_t::transport, and pn532_t::transport.

Referenced by app_main(), and PN532Adapter::begin().

◆ pn532_read_passive_target_id()

uint32_t pn532_read_passive_target_id	(	pn532_t *	dev,
		uint8_t	cardbaudrate )

Scan for a passive ISO 14443-A card and return its UID.

Sends InListPassiveTarget (0x4A) with maxTargets = 1. Blocks until a card is found or the command times out inside the PN532 firmware.

Parameters

[in]	dev	Initialised device handle.
[in]	cardbaudrate	Baud-rate selector; use PN532_MIFARE_ISO14443A for standard Mifare / ISO 14443-A cards.

Returns: 32-bit packed card UID (UID bytes packed MSB-first), or 0 if no card was found or a communication error occurred.

Note: UIDs longer than 4 bytes are truncated to the most-significant 32 bits.

Definition at line 775 of file pn532.c.

References PN532_BYTE_SHIFT_BITS, PN532_CMD_TIMEOUT_MS, PN532_INLISTPASSIVETARGET, PN532_PASSIVE_CMD_LEN, PN532_PASSIVE_EXPECTED_TARGETS, PN532_PASSIVE_MAX_TARGETS, PN532_PASSIVE_NUM_TARGETS_OFFSET, PN532_PASSIVE_RESP_LEN, PN532_PASSIVE_UID_DATA_OFFSET, PN532_PASSIVE_UID_LEN_OFFSET, read_data(), and send_command_check_ack().

Referenced by PN532Adapter::inListPassiveTarget(), and Pn532NfcTransport::inListPassiveTarget().

◆ pn532_release_target()

bool pn532_release_target ( pn532_t * dev )

Release the currently selected NFC target.

Sends InRelease (0x52) so the PN532 drops the logical target and is ready to list a new one. Should be called after finishing a card session before the next pn532_read_passive_target_id.

Parameters

[in] dev Initialised device handle.

Returns: true if the PN532 acknowledged the release successfully, false on communication failure.

Definition at line 875 of file pn532.c.

References PN532_CMD_TIMEOUT_MS, PN532_EXCHANGE_STATUS_OFFSET, PN532_EXCHANGE_STATUS_OK, PN532_EXCHANGE_TG, PN532_INRELEASE, PN532_INRELEASE_CMD_LEN, PN532_INRELEASE_RESP_LEN, read_data(), and send_command_check_ack().

Referenced by PN532Adapter::resetReader(), and Pn532NfcTransport::resetReader().

◆ pn532_sam_config()

bool pn532_sam_config ( pn532_t * dev )

Configure the PN532's Security Access Module (SAM).

Sends the SAMConfiguration command (0x14) with Normal Mode, a 1-second timeout, and IRQ enabled. Must be called (at least once) before listing passive targets or exchanging APDUs.

pn532_init already issues this command internally; application code calls it again via CW_NfcTransport::begin() / Pn532NfcTransport::begin.

Parameters

[in] dev Initialised device handle.

Returns: true on success (PN532 acknowledged and returned response code 0x15), false on timeout or unexpected response.

Definition at line 752 of file pn532.c.

References PN532_CMD_TIMEOUT_MS, PN532_SAM_CMD_LEN, PN532_SAM_NORMAL_MODE, PN532_SAM_RESP_CODE, PN532_SAM_RESP_CODE_OFFSET, PN532_SAM_RESP_LEN, PN532_SAM_TIMEOUT, PN532_SAM_USE_IRQ, PN532_SAMCONFIGURATION, read_data(), and send_command_check_ack().

Referenced by Pn532NfcTransport::begin(), and pn532_init().

◆ pn532_send_apdu()

bool pn532_send_apdu	(	pn532_t *	dev,
		const uint8_t *	apdu,
		uint8_t	apdu_len,
		uint8_t *	response,
		uint16_t *	response_len )

Exchange a single ISO-DEP APDU with the currently selected card.

Wraps the PN532 InDataExchange command (0x40). Handles both normal PN532 frames (LEN ≤ 255) and extended frames (LEN > 255) transparently; the frame format is detected from the response header.

Parameters

[in]	dev	Initialised device handle.
[in]	apdu	APDU command bytes (must not be `NULL`).
[in]	apdu_len	Length of `apdu`; must be ≤ PN532_MAX_APDU_LEN.
[out]	response	Caller-allocated buffer for the card's DataOut.
[in,out]	response_len	In: capacity of `response` in bytes. Out: number of DataOut bytes actually written.

Returns: true on success (PN532 error byte = 0x00), false on a PN532 transport error, a card-level error, or if apdu_len exceeds PN532_MAX_APDU_LEN.

Warning: response must be large enough to hold the full DataOut; if capacity is exceeded the copy is silently truncated to *response_len.

See also: pn532_release_target

Definition at line 805 of file pn532.c.

References PN532_APDU_TIMEOUT_MS, PN532_EXCHANGE_CMD_OVERHEAD, PN532_EXCHANGE_DATA_OFFSET, PN532_EXCHANGE_FRAME_MAX, PN532_EXCHANGE_LEN_BIAS, PN532_EXCHANGE_LEN_OFFSET, PN532_EXCHANGE_STATUS_OFFSET, PN532_EXCHANGE_STATUS_OK, PN532_EXCHANGE_TG, PN532_EXT_EXCHANGE_DATA_OFFSET, PN532_EXT_EXCHANGE_ERR_OFFSET, PN532_EXT_FRAME_INDICATOR, PN532_EXT_FRAME_LENHI_OFFSET, PN532_EXT_FRAME_LENLO_OFFSET, PN532_INDATAEXCHANGE, PN532_LOG_TAG, PN532_MAX_APDU_LEN, read_data_apdu_frame(), and send_command_check_ack().

Referenced by PN532Adapter::sendAPDU(), Pn532NfcTransport::sendAPDU(), PN532Adapter::sendAPDULarge(), and Pn532NfcTransport::sendAPDULarge().

Classes

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ PN532_I2C_ADDRESS

◆ PN532_MAX_APDU_LEN

◆ PN532_MIFARE_ISO14443A

Enumeration Type Documentation

◆ pn532_transport_t

Function Documentation

◆ pn532_get_firmware_version()

◆ pn532_init()

◆ pn532_read_passive_target_id()

◆ pn532_release_target()

◆ pn532_sam_config()

◆ pn532_send_apdu()