Enabling softdevice causes NFC tag to stop working intermittently

[Dash]

I have ported the NFC URI example to a custom project that I am working on (platform details listed below). I am using an Android phone running NXP tag info app to read the tag. I am using the NFC_T2T_HAL along with nfc_t2t_lib_gcc.a to create the NFC tag.

If I do not enable BLE functionality then the NFC tag can be read 100% of the time. However, when I enable BLE functionality I can only read the NFC tag around 25% of the time. When I can read the tag it is intermittent. I may be able to read the tag a few times and then it will stop. But often I cannot read the tag at all. When the tag cannot be read resetting the nRF52840 will sometimes allow the tag to be read a few times before it stops again. When the tag cannot be read I do not see any events for the NFC being triggered (field on, field off, etc). It's as if the NFC module is completely dead.

I have seen other posts regarding problems with the soft device and NFC and I believe I have incorporated all the solutions described in those posts.

I have verified 

• BOARD_PCA10056 is defined
• HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND is defined
• HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND is not defined

Any ideas as to what would cause the NFC module to work intermittently as described above?

NFC tag reader

• Samsung Galaxy S6 (model SM-G925T)
• Android 7.0
• NXP Tag Info app

Hardware

• nRF52840 DK PCA10056 0.12.0 2018.9

SDK

• nRF5_SDK_15.0.0_a53641a

Toolchain

• gcc-arm-none-eabi-7-2018-q2-update

[Simonr]

Hi David

There is a bug in the FTPAN workaround which is only found if the HFCLK is already running while using NFC. This should be fixed in SDK 15.1 and newer, although the fix is quite simple for the 15.0 SDK as well. Replace your hal_nfc_t2t.c file with this, 

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 *    software without specific prior written permission.
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 *    Nordic Semiconductor ASA integrated circuit.
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 */

#include "sdk_config.h"
#if NFC_T2T_HAL_ENABLED

#include "hal_nfc_t2t.h"
#include <stdint.h>
#include <stdbool.h>
#include "nfc_t2t_lib.h"
#include "nfc_fixes.h"
#include "nrf.h"
#include "app_util_platform.h"
#include "nordic_common.h"
#include "nrf_drv_clock.h"

#define NRF_LOG_MODULE_NAME hal_nfc
#if HAL_NFC_CONFIG_LOG_ENABLED
#define NRF_LOG_LEVEL       HAL_NFC_CONFIG_LOG_LEVEL
#define NRF_LOG_INFO_COLOR  HAL_NFC_CONFIG_INFO_COLOR
#define NRF_LOG_DEBUG_COLOR HAL_NFC_CONFIG_DEBUG_COLOR
#include "nrf_log.h"
NRF_LOG_MODULE_REGISTER();
#else // HAL_NFC_CONFIG_LOG_ENABLED
#define NRF_LOG_LEVEL       0
#include "nrf_log.h"
#endif // HAL_NFC_CONFIG_LOG_ENABLED

#if HAL_NFC_CONFIG_DEBUG_PIN_ENABLED
    #include "nrf_gpio.h"

    #define HAL_NFC_DEBUG_PIN_CONFIG(pin_num) nrf_gpio_cfg_output(pin_num)
    #define HAL_NFC_DEBUG_PIN_CLEAR(pin_num)  nrf_gpio_pin_clear(pin_num)
    #define HAL_NFC_DEBUG_PIN_SET(pin_num)    nrf_gpio_pin_set(pin_num)

    #define HAL_NFC_DEBUG_PINS_INITIALIZE()                             \
        do{                                                             \
            HAL_NFC_DEBUG_PIN_CONFIG(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);     \
            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);      \
            HAL_NFC_DEBUG_PIN_CONFIG(HAL_NFC_HCLOCK_ON_DEBUG_PIN);      \
            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_ON_DEBUG_PIN);       \
            HAL_NFC_DEBUG_PIN_CONFIG(HAL_NFC_NFC_EVENT_DEBUG_PIN);      \
            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_NFC_EVENT_DEBUG_PIN);       \
            HAL_NFC_DEBUG_PIN_CONFIG(HAL_NFC_DETECT_EVENT_DEBUG_PIN);   \
            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_DETECT_EVENT_DEBUG_PIN);    \
            HAL_NFC_DEBUG_PIN_CONFIG(HAL_NFC_TIMER4_EVENT_DEBUG_PIN);   \
            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_TIMER4_EVENT_DEBUG_PIN);    \
        } while(0)
#else
    #define HAL_NFC_DEBUG_PIN_CLEAR(pin_num)
    #define HAL_NFC_DEBUG_PIN_SET(pin_num)
    #define HAL_NFC_DEBUG_PINS_INITIALIZE()
#endif // HAL_NFC_CONFIG_DEBUG_PIN_ENABLED


/* NFC library version history:
 * #define NFC_LIB_VERSION          0x00 first experimental version intended for nRF52 IC rev. Engineering A (PCA10036, part of nRF52 Preview Development Kit)
 * #define NFC_LIB_VERSION          0x01 experimental version intended for nRF52 IC rev. Engineering B (PCA10040, part of nRF52 Development Kit)
 * #define NFC_LIB_VERSION          0x02 experimental version intended for fix IC-12826 and fix: not released HFCLK in SENSE mode
 * #define NFC_LIB_VERSION          0x03 experimental version intended for support logging module
 * #define NFC_LIB_VERSION          0x04 experimental version intended for nRF52840 IC rev. Engineering A (PCA10056, part of nRF52840 Preview Development Kit). Removed PCA10036 support.
 */

#define NFC_LIB_VERSION             0x03u                                       /**< Internal: current NFC lib. version  */

#define T2T_INTERNAL_BYTES_NR       10u                                         /**< Number of internal bytes defined by Type 2 Tag Operation Technical Specification */
#define CASCADE_TAG_BYTE            0x88u                                       /**< Constant defined by ISO/EIC 14443-3 */

#define NFCID1_3RD_LAST_BYTE2_SHIFT 16u                                         /**< Shift value for NFC ID byte 2 */
#define NFCID1_3RD_LAST_BYTE1_SHIFT 8u                                          /**< Shift value for NFC ID byte 1 */
#define NFCID1_3RD_LAST_BYTE0_SHIFT 0u                                          /**< Shift value for NFC ID byte 0 */
#define NFCID1_2ND_LAST_BYTE2_SHIFT 16u                                         /**< Shift value for NFC ID byte 2 */
#define NFCID1_2ND_LAST_BYTE1_SHIFT 8u                                          /**< Shift value for NFC ID byte 1 */
#define NFCID1_2ND_LAST_BYTE0_SHIFT 0u                                          /**< Shift value for NFC ID byte 0 */
#define NFCID1_LAST_BYTE3_SHIFT     24u                                         /**< Shift value for NFC ID byte 3 */
#define NFCID1_LAST_BYTE2_SHIFT     16u                                         /**< Shift value for NFC ID byte 2 */
#define NFCID1_LAST_BYTE1_SHIFT     8u                                          /**< Shift value for NFC ID byte 1 */
#define NFCID1_LAST_BYTE0_SHIFT     0u                                          /**< Shift value for NFC ID byte 0 */

#define NFCID1_SINGLE_SIZE          4u                                          /**< Length of single size NFCID1 */
#define NFCID1_DOUBLE_SIZE          7u                                          /**< Length of double size NFCID1 */
#define NFCID1_TRIPLE_SIZE          10u                                         /**< Length of triple size NFCID1 */
#define NFCID1_DEFAULT_LENGHT       NFCID1_DOUBLE_SIZE                          /**< Length of NFCID1 if user does not provide one */
#define NFCID1_MAX_LENGHT           NFCID1_TRIPLE_SIZE                          /**< Maximum length of NFCID1 */

#define NFC_RX_BUFFER_SIZE          16u                                         /**< NFC Rx data buffer size */
#define T2T_READ_CMD                0x30u                                       /**< Type 2 Tag Read command identifier */
#define NFC_SLP_REQ_CMD             0x50u                                       /**< NFC SLP_REQ command identifier */
#define NFC_CRC_SIZE                2u                                          /**< CRC size in bytes */

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
    #define NRF_NFCT_ERRORSTATUS_ALL (NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk)    /**< Mask for clearing all error flags in NFCT_ERRORSTATUS register */
#else
    #define NRF_NFCT_ERRORSTATUS_ALL    (NFCT_ERRORSTATUS_NFCFIELDTOOWEAK_Msk   | \
                                        NFCT_ERRORSTATUS_NFCFIELDTOOSTRONG_Msk  | \
                                        NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk)    /**< Mask for clearing all error flags in NFCT_ERRORSTATUS register */
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

#define NRF_NFCT_FRAMESTATUS_RX_MSK (NFCT_FRAMESTATUS_RX_OVERRUN_Msk      | \
                                     NFCT_FRAMESTATUS_RX_PARITYSTATUS_Msk | \
                                     NFCT_FRAMESTATUS_RX_CRCERROR_Msk)          /**< Mask for clearing all flags in NFCT_FRAMESTATUS_RX register */
#define NFC_FIELD_ON_MASK            NFCT_FIELDPRESENT_LOCKDETECT_Msk           /**< Mask for checking FIELDPRESENT register for state: FIELD ON. */
#define NFC_FIELD_OFF_MASK           NFCT_FIELDPRESENT_FIELDPRESENT_Msk         /**< Mask for checking FIELDPRESENT register for state: FIELD OFF. */

#define NRF_NFCT_DEFAULTSTATESLEEP     (*(uint32_t volatile *)(0x40005420))     /**< The default state of NFCT. */
#define NRF_NFCT_DEFAULTSTATESLEEP_MSK 0x1UL                                    /**< Mask for checking the default state of NFCT. */

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
    #define NRF_NFCT_ACTIVATE_CONDS_THR    2                                        /**< Number of required conditions to activate NFCT. */
    #define NRF_NFCT_ACTIVATE_DELAY        1000                                     /**< Minimal delay in us between NFC field detection and activation of NFCT. */
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

typedef enum
{
    NFC_FIELD_STATE_NONE,           /**< Initial value indicating no NFCT Field events. */
    NFC_FIELD_STATE_OFF,            /**< NFCT FIELDLOST Event has been set. */
    NFC_FIELD_STATE_ON,             /**< NFCT FIELDDETECTED Event has been set. */
    NFC_FIELD_STATE_UNKNOWN         /**< Both NFCT Field Events have been set - ambiguous state. */
}nfct_field_sense_state_t;

/* Static function declarations */
static inline void nrf_nfct_event_clear(volatile uint32_t * p_event);
static inline void nrf_nfct_clock_event_handler(nrf_drv_clock_evt_type_t event);
static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state);
static void hal_nfc_nfcid1_default_bytes(void);
static void hal_nfc_nfcid1_registers_setup(void);
static void hal_nfc_internal_bytes_setup(void);

/* Static data */
static hal_nfc_callback_t           m_nfc_lib_callback = (hal_nfc_callback_t) NULL;    /**< Callback to nfc_lib layer */
static void *                       m_nfc_lib_context;                                 /**< Callback execution context */
static volatile uint8_t             m_nfc_rx_buffer[NFC_RX_BUFFER_SIZE]   = {0};       /**< Buffer for NFC Rx data */
static volatile bool                m_slp_req_received                    = false;     /**< Flag indicating that SLP_REQ Command was received */
static volatile bool                m_field_on                            = false;     /**< Flag indicating that NFC Tag field is present */
static nrf_drv_clock_handler_item_t m_clock_handler_item;                              /**< Clock event handler item structure */
static uint8_t                      m_nfcid1_length                       = 0;         /**< Length of NFCID1 provided by user or 0 if not initialized yet */
static uint8_t                      m_nfcid1_data[NFCID1_MAX_LENGHT]      = {0};       /**< Content of NFCID1 */

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
static volatile bool                m_nfc_fieldevents_filter_active       = false;     /**< Flag indicating that field events are ignored. */
static volatile uint32_t            m_nfc_activate_conditions             = 0;         /**< Number of activation conditions that are met. */
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
static volatile uint32_t            m_nfc_fieldpresent_mask               = NFC_FIELD_OFF_MASK;   /**< Mask used for NFC Field polling in NFCT_FIELDPRESENT register */
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#define NRF_NFCT_POWER  (*(uint32_t volatile *)(0x40005FFC))

#define NFC_HAL_FIELDPRESENT_MASK      (NFCT_FIELDPRESENT_LOCKDETECT_Msk | \
                                       NFCT_FIELDPRESENT_FIELDPRESENT_Msk)

#define NFC_HAL_FIELDPRESENT_IS_LOST   ((NFCT_FIELDPRESENT_FIELDPRESENT_NoField <<  \
                                       NFCT_FIELDPRESENT_FIELDPRESENT_Pos) |        \
                                       (NFCT_FIELDPRESENT_LOCKDETECT_NotLocked <<  \
                                       NFCT_FIELDPRESENT_LOCKDETECT_Pos))

#ifndef HAL_NFC_FIELD_TIMER_PERIOD
    #define HAL_NFC_FIELD_TIMER_PERIOD    100  /* unit - us */
#endif

static inline void hal_nfc_re_setup(void);
static void hal_nfc_field_check(void);

#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
static void hal_nfc_activate_check(void)
{
    static bool is_field_validation_pending = false;

    if (is_field_validation_pending)
    {
        is_field_validation_pending     = false;
        m_nfc_fieldevents_filter_active = false;

        // Check the field status with FIELDPRESENT and take action if field is lost.
        nrf_nfct_field_event_handler(NFC_FIELD_STATE_UNKNOWN);
        return;
    }

    m_nfc_activate_conditions++;
    if (m_nfc_activate_conditions == NRF_NFCT_ACTIVATE_CONDS_THR)
    {
        m_nfc_activate_conditions = 0;

        NRF_NFCT->TASKS_ACTIVATE    = 1;
        is_field_validation_pending = true;;

        // Start the timer second time to validate if tag has locked to the field
        NRF_TIMER4->TASKS_CLEAR = 1;
        NRF_TIMER4->TASKS_START = 1;
    }
}
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

#if defined(HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND) || defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)

static void field_timer_with_callback_config(void)
{
    NRF_TIMER4->MODE      = TIMER_MODE_MODE_Timer << TIMER_MODE_MODE_Pos;
    NRF_TIMER4->BITMODE   = TIMER_BITMODE_BITMODE_16Bit << TIMER_BITMODE_BITMODE_Pos;
    NRF_TIMER4->PRESCALER = 4 << TIMER_PRESCALER_PRESCALER_Pos;
#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
    NRF_TIMER4->CC[0]     = HAL_NFC_FIELD_TIMER_PERIOD << TIMER_CC_CC_Pos;
#else
    NRF_TIMER4->CC[0]     = NRF_NFCT_ACTIVATE_DELAY << TIMER_CC_CC_Pos;
#endif
    NRF_TIMER4->SHORTS    = TIMER_SHORTS_COMPARE0_CLEAR_Enabled << TIMER_SHORTS_COMPARE0_CLEAR_Pos;
    NRF_TIMER4->INTENSET  = TIMER_INTENSET_COMPARE0_Set << TIMER_INTENSET_COMPARE0_Pos;

    NVIC_ClearPendingIRQ(TIMER4_IRQn);
    NVIC_SetPriority(TIMER4_IRQn, NFCT_CONFIG_IRQ_PRIORITY);
    NVIC_EnableIRQ(TIMER4_IRQn);
}

void TIMER4_IRQHandler(void)
{
    HAL_NFC_DEBUG_PIN_SET(HAL_NFC_TIMER4_EVENT_DEBUG_PIN);
#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
    hal_nfc_field_check();
#else
    NRF_TIMER4->TASKS_SHUTDOWN = 1;
    hal_nfc_activate_check();
#endif
    NRF_TIMER4->EVENTS_COMPARE[0] = 0;
    HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_TIMER4_EVENT_DEBUG_PIN);
}

#endif // defined(HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND) || defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)

/**
 * @brief Common part of setup used for NFCT initialization and reinitialization.
 */
#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
static void hal_nfc_common_hw_setup()
#else
static inline void hal_nfc_common_hw_setup()
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
{
#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
    if (type_52840_sample_check())
    {
        /* Begin: Bugfix for FTPAN-98 */
        *(volatile uint32_t *) 0x4000568C = 0x00038148;
        /* End: Bugfix for FTPAN-98 */
        /* Begin: Bugfix for FTPAN-144 */
        *(volatile uint32_t *) 0x4000561c = 0x01;
        *(volatile uint32_t *) 0x4000562c = 0x3F;
        *(volatile uint32_t *) 0x4000563c = 0x0;
        /* End: Bugfix for FTPAN-144 */
    }
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
    NRF_NFCT->INTENSET = (NFCT_INTENSET_FIELDDETECTED_Enabled << NFCT_INTENSET_FIELDDETECTED_Pos);
#else
    NRF_NFCT->INTENSET = (NFCT_INTENSET_FIELDDETECTED_Enabled << NFCT_INTENSET_FIELDDETECTED_Pos) |
                         (NFCT_INTENSET_FIELDLOST_Enabled     << NFCT_INTENSET_FIELDLOST_Pos);
#endif

    NRF_NFCT->INTENSET = (NFCT_INTENSET_ERROR_Enabled    << NFCT_INTENSET_ERROR_Pos) |
                         (NFCT_INTENSET_SELECTED_Enabled << NFCT_INTENSET_SELECTED_Pos);

    // Use Window Grid frame delay mode.
    NRF_NFCT->FRAMEDELAYMODE = (NFCT_FRAMEDELAYMODE_FRAMEDELAYMODE_WindowGrid <<
                               NFCT_FRAMEDELAYMODE_FRAMEDELAYMODE_Pos) &
                               NFCT_FRAMEDELAYMODE_FRAMEDELAYMODE_Msk;

    hal_nfc_nfcid1_registers_setup();
}

/** @brief Setup NRF_NFCT->NFCID1 and NRF_NFCT->SENSRES registers based on m_nfcid1_data and m_nfcid1_length variables.
 */
static void hal_nfc_nfcid1_registers_setup(void)
{
    uint32_t sens_res_size;         // Value that will be written to NRF_NFCT->SENSRES
    uint8_t* p_nfcid_remaining_data;  // Points to the first byte of m_nfcid1_data remaining to write to NRF_NFCT->NFCID1 registers

    p_nfcid_remaining_data = m_nfcid1_data;

    if (m_nfcid1_length == NFCID1_SINGLE_SIZE)
    {
        sens_res_size = NFCT_SENSRES_NFCIDSIZE_NFCID1Single;
    }
    else
    {
        if (m_nfcid1_length == NFCID1_DOUBLE_SIZE)
        {
            sens_res_size = NFCT_SENSRES_NFCIDSIZE_NFCID1Double;
        }
        else // then m_nfcid1_length == NFCID1_TRIPLE_SIZE
        {
            /* MSB of NFCID1_3RD_LAST register is not used - always 0 */
            NRF_NFCT->NFCID1_3RD_LAST =
                ((uint32_t) p_nfcid_remaining_data[0] << NFCID1_3RD_LAST_BYTE2_SHIFT) |
                ((uint32_t) p_nfcid_remaining_data[1] << NFCID1_3RD_LAST_BYTE1_SHIFT) |
                ((uint32_t) p_nfcid_remaining_data[2] << NFCID1_3RD_LAST_BYTE0_SHIFT);
            p_nfcid_remaining_data += 3;
            sens_res_size           = NFCT_SENSRES_NFCIDSIZE_NFCID1Triple;
        }
        /* MSB of NFCID1_2ND_LAST register is not used - always 0 */
        NRF_NFCT->NFCID1_2ND_LAST =
            ((uint32_t) p_nfcid_remaining_data[0] << NFCID1_2ND_LAST_BYTE2_SHIFT) |
            ((uint32_t) p_nfcid_remaining_data[1] << NFCID1_2ND_LAST_BYTE1_SHIFT) |
            ((uint32_t) p_nfcid_remaining_data[2] << NFCID1_2ND_LAST_BYTE0_SHIFT);
        p_nfcid_remaining_data += 3;
    }

    NRF_NFCT->NFCID1_LAST =
        ((uint32_t) p_nfcid_remaining_data[0] << NFCID1_LAST_BYTE3_SHIFT) |
        ((uint32_t) p_nfcid_remaining_data[1] << NFCID1_LAST_BYTE2_SHIFT) |
        ((uint32_t) p_nfcid_remaining_data[2] << NFCID1_LAST_BYTE1_SHIFT) |
        ((uint32_t) p_nfcid_remaining_data[3] << NFCID1_LAST_BYTE0_SHIFT);

    /* Begin: Bugfix for FTPAN-25 (IC-9929) */
    /* Workaround for wrong SENSRES values require using SDD00001, but here SDD00100 is used
       because it's required to operate with Windows Phone */
    NRF_NFCT->SENSRES =
            (sens_res_size << NFCT_SENSRES_NFCIDSIZE_Pos) |
            (NFCT_SENSRES_BITFRAMESDD_SDD00100   << NFCT_SENSRES_BITFRAMESDD_Pos);
    /* End:   Bugfix for FTPAN-25 (IC-9929)*/
}

/** @brief Call nfc_t2t_internal_set() with data generated based on m_nfcid1_data and m_nfcid1_length variables.
 */
static void hal_nfc_internal_bytes_setup(void)
{
    if (m_nfcid1_length == NFCID1_TRIPLE_SIZE)
    {
        (void) nfc_t2t_internal_set(m_nfcid1_data, T2T_INTERNAL_BYTES_NR);
    }
    else
    {
        uint8_t  nfc_internal[T2T_INTERNAL_BYTES_NR];

        if (m_nfcid1_length == NFCID1_DOUBLE_SIZE)
        {
                                                                  // CASCADE TAG send over the air, but not included in internal data
            nfc_internal[0] = m_nfcid1_data[0];                   // UID0 = Manufacturer ID
            nfc_internal[1] = m_nfcid1_data[1];                   // UID1
            nfc_internal[2] = m_nfcid1_data[2];                   // UID2
            nfc_internal[3] = (uint8_t) CASCADE_TAG_BYTE ^ nfc_internal[0] ^
                              nfc_internal[1] ^ nfc_internal[2];  // BCC0 = XOR over the 4 previous bytes
            nfc_internal[4] = m_nfcid1_data[3];                   // UID3
            nfc_internal[5] = m_nfcid1_data[4];                   // UID4
            nfc_internal[6] = m_nfcid1_data[5];                   // UID5
            nfc_internal[7] = m_nfcid1_data[6];                   // UID6
            nfc_internal[8] = nfc_internal[4] ^ nfc_internal[5] ^
                              nfc_internal[6] ^ nfc_internal[7];  // BCC1 = XOR over the 4 previous bytes
            nfc_internal[9] = NFC_LIB_VERSION;                    // For internal use
        }
        else // then m_nfcid1_length == NFCID1_SINGLE_SIZE
        {
            nfc_internal[0] = m_nfcid1_data[0];                   // UID0 = Manufacturer ID
            nfc_internal[1] = m_nfcid1_data[1];                   // UID1
            nfc_internal[2] = m_nfcid1_data[2];                   // UID2
            nfc_internal[3] = m_nfcid1_data[3];                   // UID3
            nfc_internal[4] = nfc_internal[0] ^ nfc_internal[1] ^
                              nfc_internal[2] ^ nfc_internal[3];  // BCC0 = XOR over the 4 previous bytes
            memset(&nfc_internal[5], 0xFF, 4);                    // 4-byte padding
            nfc_internal[9] = NFC_LIB_VERSION;                    // For internal use
        }

        (void) nfc_t2t_internal_set(nfc_internal, T2T_INTERNAL_BYTES_NR);
    }
}

ret_code_t hal_nfc_setup(hal_nfc_callback_t callback, void * p_context)
{
    m_nfc_lib_callback = callback;
    m_nfc_lib_context  = p_context;

    if (m_nfcid1_length == 0)
    {
        m_nfcid1_length = NFCID1_DEFAULT_LENGHT;
        hal_nfc_nfcid1_default_bytes();
    }

    hal_nfc_common_hw_setup();
    hal_nfc_internal_bytes_setup();

    /* Initialize SDK Clock module for handling high precission clock requests */
    m_clock_handler_item.event_handler = nrf_nfct_clock_event_handler;
    m_clock_handler_item.p_next        = NULL;

    ret_code_t err_code = nrf_drv_clock_init();

#if defined(HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND) || defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)
    #if defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)
    if (!type_52840_sample_check())
    #endif // defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)
    {
        field_timer_with_callback_config();
    }
#endif // defined(HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND) || defined(HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND)

    NRF_LOG_INFO("Init");
    HAL_NFC_DEBUG_PINS_INITIALIZE();

    if ((err_code == NRF_SUCCESS) || (err_code == NRF_ERROR_MODULE_ALREADY_INITIALIZED))
    {
        return NRF_SUCCESS;
    }
    else
    {
        return NRF_ERROR_INTERNAL;
    }
}

/**@brief Function for clearing an event flag in NRF_NFCT registers.
 *
 * @param[in]  p_event  Pointer to event register.
 *
 */
static inline void nrf_nfct_event_clear(volatile uint32_t * p_event)
{
    *p_event = 0;

    /* Perform read to ensure clearing is effective */
    volatile uint32_t dummy = *p_event;
    (void)dummy;
}

/**@brief Function for handling events from Clock Module.
 *
 * @param[in]  event  Clock event.
 *
 */
static inline void nrf_nfct_clock_event_handler(nrf_drv_clock_evt_type_t event)
{
    switch(event)
    {
        case NRF_DRV_CLOCK_EVT_HFCLK_STARTED:
            /* Activate NFCT only when HFXO is running */
            HAL_NFC_DEBUG_PIN_SET(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
            if (type_52840_final_check())
            {
                hal_nfc_activate_check();
            }
            else
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
            {
                NRF_NFCT->TASKS_ACTIVATE = 1;
            }

            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!
            break;

        default:
            /* No implementation required */
            break;
    }
}

#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
static inline void nrf_nfct_field_lost_hfclk_handle(void)
{
    /* Begin:   Bugfix for FTPAN-116 (IC-12886) */
    // reset the NFC for release HFCLK
    __DMB();
    NRF_NFCT_POWER = 0;
    __DMB();
    NRF_NFCT_POWER = 1;
    /* END:   Bugfix for FTPAN-116 (IC-12886) */

}
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
/**@brief Function for evaluating and handling NFC field events.
 *
 * @param[in]  field_state  Current field state.
 *
 */
static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state)
{
#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
    bool is_first_sample = type_52840_sample_check();

    if((!is_first_sample) && (m_nfc_fieldevents_filter_active))
    {
        return;
    }
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

    if (field_state == NFC_FIELD_STATE_UNKNOWN)
    {
        /* Probe NFC field */
        uint32_t field_present = NRF_NFCT->FIELDPRESENT;

        if (field_present & m_nfc_fieldpresent_mask)
        {
            field_state = NFC_FIELD_STATE_ON;
        }
        else
        {
            field_state = NFC_FIELD_STATE_OFF;
        }
    }

    /* Field event service */
    switch(field_state)
    {
        case NFC_FIELD_STATE_ON:
            if (!m_field_on)
            {
#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
                /* Begin: Bugfix for FTPAN-190 */
                if (!is_first_sample)
                {
                    m_nfc_activate_conditions       = 0;
                    m_nfc_fieldevents_filter_active = true;

                    NRF_TIMER4->TASKS_CLEAR = 1;
                    NRF_TIMER4->TASKS_START = 1;
                }
                /* END: Bugfix for FTPAN-190 */
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

                HAL_NFC_DEBUG_PIN_SET(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!
                nrf_drv_clock_hfclk_request(&m_clock_handler_item);
                HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!
            }
            m_field_on = true;
            break;

        case NFC_FIELD_STATE_OFF:
            HAL_NFC_DEBUG_PIN_SET(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);  //DEBUG!

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
            /* Begin: Bugfix for FTPAN-116 (IC-12886) */
            if (is_first_sample)
            {
                *(volatile uint32_t *)0x40005010 = 1;
            }
            /* END: Bugfix for FTPAN-116 (IC-12886) */
#endif // HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND

            NRF_NFCT->TASKS_SENSE = 1;
            nrf_drv_clock_hfclk_release();
            m_field_on = false;

            NRF_NFCT->INTENCLR =
                (NFCT_INTENCLR_RXFRAMEEND_Clear << NFCT_INTENCLR_RXFRAMEEND_Pos) |
                (NFCT_INTENCLR_RXERROR_Clear    << NFCT_INTENCLR_RXERROR_Pos);

            /* Change mask to FIELD_OFF state - trigger FIELD_ON even if HW has not locked to the field */
            m_nfc_fieldpresent_mask = NFC_FIELD_OFF_MASK;

            if ((m_nfc_lib_callback != NULL) )
            {
                m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_OFF, 0, 0);
            }

            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);  //DEBUG!
            break;

        default:
            /* No implementation required */
            break;
    }
}
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND


/** @brief Writes default values to m_nfcid1_data based on NRF_FICR->NFC registers.
 */
static void hal_nfc_nfcid1_default_bytes(void)
{
    uint32_t nfc_tag_header0 = NRF_FICR->NFC.TAGHEADER0;
    uint32_t nfc_tag_header1 = NRF_FICR->NFC.TAGHEADER1;
    uint32_t nfc_tag_header2 = NRF_FICR->NFC.TAGHEADER2;

    m_nfcid1_data[0] = (uint8_t) LSB_32(nfc_tag_header0 >> 0);
    m_nfcid1_data[1] = (uint8_t) LSB_32(nfc_tag_header0 >> 8);
    m_nfcid1_data[2] = (uint8_t) LSB_32(nfc_tag_header0 >> 16);
    m_nfcid1_data[3] = (uint8_t) LSB_32(nfc_tag_header1 >> 0);
    m_nfcid1_data[4] = (uint8_t) LSB_32(nfc_tag_header1 >> 8);
    m_nfcid1_data[5] = (uint8_t) LSB_32(nfc_tag_header1 >> 16);
    m_nfcid1_data[6] = (uint8_t) LSB_32(nfc_tag_header1 >> 24);
    m_nfcid1_data[7] = (uint8_t) LSB_32(nfc_tag_header2 >> 0);
    m_nfcid1_data[8] = (uint8_t) LSB_32(nfc_tag_header2 >> 8);
    m_nfcid1_data[9] = (uint8_t) LSB_32(nfc_tag_header2 >> 16);
}


/** @brief Resets NFCT peripheral to its default state before automatic collision resolution
 *         procedure.
 */
static inline void nrf_nfct_default_state_reset(void)
{
    if (NRF_NFCT_DEFAULTSTATESLEEP & NRF_NFCT_DEFAULTSTATESLEEP_MSK) // Default state is SLEEP_A
    {
        NRF_NFCT->TASKS_GOSLEEP = 1;
    }
    else // Default state is IDLE
    {
        NRF_NFCT->TASKS_GOIDLE = 1;
    }

    /* Disable RX here (will be enabled at SELECTED) */
    NRF_NFCT->INTENCLR = NFCT_INTENCLR_RXFRAMEEND_Clear <<
                         NFCT_INTENCLR_RXFRAMEEND_Pos;
}


ret_code_t hal_nfc_parameter_set(hal_nfc_param_id_t id, void * p_data, size_t data_length)
{
    if (id == HAL_NFC_PARAM_ID_NFCID1)
    {
        if (data_length == 1)
        {
            uint8_t id_length = *((uint8_t *) p_data);
            if (id_length == NFCID1_SINGLE_SIZE || id_length == NFCID1_DOUBLE_SIZE ||
                id_length == NFCID1_TRIPLE_SIZE)
            {
                m_nfcid1_length = id_length;
                hal_nfc_nfcid1_default_bytes();
            }
            else
            {
                return NRF_ERROR_INVALID_LENGTH;
            }
        }
        else if (data_length == NFCID1_SINGLE_SIZE || data_length == NFCID1_DOUBLE_SIZE ||
            data_length == NFCID1_TRIPLE_SIZE)
        {
            m_nfcid1_length = (uint8_t) data_length;
            memcpy(m_nfcid1_data, p_data, data_length);
        }
        else
        {
            return NRF_ERROR_INVALID_LENGTH;
        }
        hal_nfc_nfcid1_registers_setup();
        hal_nfc_internal_bytes_setup();
    }

    return NRF_SUCCESS;
}

ret_code_t hal_nfc_parameter_get(hal_nfc_param_id_t id, void * p_data, size_t * p_max_data_length)
{
    if (id == HAL_NFC_PARAM_ID_NFCID1)
    {
        if (m_nfcid1_length == 0)
        {
            m_nfcid1_length = NFCID1_DEFAULT_LENGHT;
            hal_nfc_nfcid1_default_bytes();
        }

        if (*p_max_data_length < (size_t) m_nfcid1_length)
        {
            return NRF_ERROR_DATA_SIZE;
        }

        *p_max_data_length = (size_t) m_nfcid1_length;
        memcpy(p_data, m_nfcid1_data, m_nfcid1_length);
    }

    return NRF_SUCCESS;
}


ret_code_t hal_nfc_start(void)
{
    NRF_NFCT->ERRORSTATUS = NRF_NFCT_ERRORSTATUS_ALL;
    NRF_NFCT->TASKS_SENSE = 1;

    NVIC_ClearPendingIRQ(NFCT_IRQn);
    NVIC_SetPriority(NFCT_IRQn, NFCT_CONFIG_IRQ_PRIORITY);
    NVIC_EnableIRQ(NFCT_IRQn);

    NRF_LOG_INFO("Start");
    return NRF_SUCCESS;
}

ret_code_t hal_nfc_send(const uint8_t * p_data, size_t data_length)
{
    if (data_length == 0)
    {
        return NRF_ERROR_DATA_SIZE;
    }

    /* Ignore previous TX END events, SW takes care only for data frames which tranmission is triggered in this function */
    nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);

    NRF_NFCT->PACKETPTR     = (uint32_t) p_data;
    NRF_NFCT->TXD.AMOUNT    = (data_length << NFCT_TXD_AMOUNT_TXDATABYTES_Pos) &
                               NFCT_TXD_AMOUNT_TXDATABYTES_Msk;
    NRF_NFCT->INTENSET      = (NFCT_INTENSET_TXFRAMEEND_Enabled << NFCT_INTENSET_TXFRAMEEND_Pos);
    NRF_NFCT->TASKS_STARTTX = 1;

    NRF_LOG_INFO("Send");
    return NRF_SUCCESS;
}

ret_code_t hal_nfc_stop(void)
{
    NRF_NFCT->TASKS_DISABLE = 1;

    NRF_LOG_INFO("Stop");
    return NRF_SUCCESS;
}

ret_code_t hal_nfc_done(void)
{
    m_nfc_lib_callback = (hal_nfc_callback_t) NULL;

    return NRF_SUCCESS;
}

void NFCT_IRQHandler(void)
{
    nfct_field_sense_state_t current_field = NFC_FIELD_STATE_NONE;

    HAL_NFC_DEBUG_PIN_SET(HAL_NFC_NFC_EVENT_DEBUG_PIN);  //DEBUG!

    if (NRF_NFCT->EVENTS_FIELDDETECTED && (NRF_NFCT->INTEN & NFCT_INTEN_FIELDDETECTED_Msk))
    {
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_FIELDDETECTED);
        HAL_NFC_DEBUG_PIN_SET(HAL_NFC_DETECT_EVENT_DEBUG_PIN);  //DEBUG!
        current_field = NFC_FIELD_STATE_ON;
        HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_DETECT_EVENT_DEBUG_PIN);  //DEBUG!

        NRF_LOG_ERROR("Field detected");
    }

#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
    if (NRF_NFCT->EVENTS_FIELDLOST && (NRF_NFCT->INTEN & NFCT_INTEN_FIELDLOST_Msk))
    {
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_FIELDLOST);
        current_field =
           (current_field == NFC_FIELD_STATE_NONE) ? NFC_FIELD_STATE_OFF : NFC_FIELD_STATE_UNKNOWN;

        NRF_LOG_ERROR("Field lost");
    }
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

    /* Perform actions if any FIELD event is active */
    if (current_field != NFC_FIELD_STATE_NONE)
    {
       nrf_nfct_field_event_handler(current_field);
    }

    if (NRF_NFCT->EVENTS_RXFRAMEEND && (NRF_NFCT->INTEN & NFCT_INTEN_RXFRAMEEND_Msk))
    {
        /* Take into account only number of whole bytes */
        uint32_t rx_status    = 0;
        uint32_t rx_data_size = ((NRF_NFCT->RXD.AMOUNT & NFCT_RXD_AMOUNT_RXDATABYTES_Msk) >>
                                 NFCT_RXD_AMOUNT_RXDATABYTES_Pos) - NFC_CRC_SIZE;
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMEEND);


        if (NRF_NFCT->EVENTS_RXERROR && (NRF_NFCT->INTEN & NFCT_INTEN_RXERROR_Msk))
        {
            rx_status = (NRF_NFCT->FRAMESTATUS.RX & NRF_NFCT_FRAMESTATUS_RX_MSK);
            nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXERROR);

            NRF_LOG_DEBUG("Rx error (0x%x)", (unsigned int) rx_status);

            /* Clear rx frame status */
            NRF_NFCT->FRAMESTATUS.RX = NRF_NFCT_FRAMESTATUS_RX_MSK;
        }

        /* Go back to idle state if NFC-A frame with Transmission Errors occurs. */
        if (rx_status)
        {
            nrf_nfct_default_state_reset();
        }
        else
        {
            /* Look for Tag 2 Type READ Command */
            if (m_nfc_rx_buffer[0] == T2T_READ_CMD)
            {
                if (m_nfc_lib_callback != NULL)
                {
                    /* This callback should trigger transmission of READ Response */
                    m_nfc_lib_callback(m_nfc_lib_context,
                                       HAL_NFC_EVENT_DATA_RECEIVED,
                                       (void*)m_nfc_rx_buffer,
                                       rx_data_size);
                }
            }
            else
            {
                /* Indicate that SLP_REQ was received - this will cause FRAMEDELAYTIMEOUT error */
                if (m_nfc_rx_buffer[0] == NFC_SLP_REQ_CMD)
                {
                    m_slp_req_received = true;
                    /* No need to parse incoming frames, wait for SELECTED */
                    NRF_NFCT->INTENCLR = NFCT_INTENCLR_RXFRAMEEND_Clear <<
                                         NFCT_INTENCLR_RXFRAMEEND_Pos;
                }
                else
                {
                    nrf_nfct_default_state_reset();
                }
            }
        }

        NRF_LOG_ERROR("Rx fend");
    }

    if (NRF_NFCT->EVENTS_TXFRAMEEND && (NRF_NFCT->INTEN & NFCT_INTEN_TXFRAMEEND_Msk))
    {
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);

        /* Disable TX END event to ignore frame transmission other than READ response */
        NRF_NFCT->INTENCLR = (NFCT_INTENCLR_TXFRAMEEND_Clear << NFCT_INTENCLR_TXFRAMEEND_Pos);

        /* Set up for reception */
        NRF_NFCT->PACKETPTR          = (uint32_t) m_nfc_rx_buffer;
        NRF_NFCT->MAXLEN             = NFC_RX_BUFFER_SIZE;
        NRF_NFCT->TASKS_ENABLERXDATA = 1;

        if (m_nfc_lib_callback != NULL)
        {
            m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_DATA_TRANSMITTED, 0, 0);
        }

        NRF_LOG_DEBUG("Tx fend");
    }

    if (NRF_NFCT->EVENTS_SELECTED && (NRF_NFCT->INTEN & NFCT_INTEN_SELECTED_Msk))
    {
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_SELECTED);
        /* Clear also RX END and RXERROR events because SW does not take care of commands which were received before selecting the tag */
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMEEND);
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXERROR);

        /* Set up registers for EasyDMA and start receiving packets */
        NRF_NFCT->PACKETPTR          = (uint32_t) m_nfc_rx_buffer;
        NRF_NFCT->MAXLEN             = NFC_RX_BUFFER_SIZE;
        NRF_NFCT->TASKS_ENABLERXDATA = 1;

        NRF_NFCT->INTENSET = (NFCT_INTENSET_RXFRAMEEND_Enabled << NFCT_INTENSET_RXFRAMEEND_Pos) |
                             (NFCT_INTENSET_RXERROR_Enabled    << NFCT_INTENSET_RXERROR_Pos);

        /* At this point any previous error status can be ignored */
        NRF_NFCT->FRAMESTATUS.RX = NRF_NFCT_FRAMESTATUS_RX_MSK;
        NRF_NFCT->ERRORSTATUS    = NRF_NFCT_ERRORSTATUS_ALL;

#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND
        /* Change mask to FIELD_ON state - trigger FIELD_ON only if HW has locked to the field */
        m_nfc_fieldpresent_mask = NFC_FIELD_ON_MASK;
#endif

        if (m_nfc_lib_callback != NULL)
        {
            m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_ON, 0, 0);
        }

        NRF_LOG_ERROR("Selected");
    }

    if (NRF_NFCT->EVENTS_ERROR && (NRF_NFCT->INTEN & NFCT_INTEN_ERROR_Msk))
    {
        uint32_t err_status = NRF_NFCT->ERRORSTATUS;
        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_ERROR);

        /* Clear FRAMEDELAYTIMEOUT error (expected HW behaviour) when SLP_REQ command was received */
        if ((err_status & NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk) && m_slp_req_received)
        {
            NRF_NFCT->ERRORSTATUS = NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk;
            m_slp_req_received    = false;

            NRF_LOG_DEBUG("RX: SLP_REQ");
        }
        /* Report any other error */
        err_status &= ~NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk;
        if (err_status)
        {
            NRF_LOG_DEBUG("Error (0x%x)", (unsigned int) err_status);
        }

        /* Clear error status */
        NRF_NFCT->ERRORSTATUS = NRF_NFCT_ERRORSTATUS_ALL;
    }

    HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_NFC_EVENT_DEBUG_PIN);  //DEBUG!
}


#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#ifdef HAL_NFC_NRF52840_ENGINEERING_ABC_WORKAROUND
    #error Wrong workaround combination
#endif

static uint32_t   field_state_cnt = 0;
/**
 * @brief Function for evaluating and handling NFC fieldlost event.
 */
static void hal_nfc_field_check(void)
{
    uint32_t nfc_fieldpresen_masked;

    nfc_fieldpresen_masked = NRF_NFCT->FIELDPRESENT & NFC_HAL_FIELDPRESENT_MASK;

    if (nfc_fieldpresen_masked == NFC_HAL_FIELDPRESENT_IS_LOST)
    {
        ++field_state_cnt;
        if (field_state_cnt > 7)
        {
            HAL_NFC_DEBUG_PIN_SET(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);  //DEBUG!

            NRF_TIMER4->TASKS_SHUTDOWN = 1;

            nrf_drv_clock_hfclk_release();

            nrf_nfct_field_lost_hfclk_handle();

            if ((m_nfc_lib_callback != NULL))
            {
                m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_OFF, 0, 0);
            }
            m_field_on = false;

            /* Begin:   Bugfix for FTPAN-116 (IC-12886) */
            // resume the NFCT to initialized state
            hal_nfc_re_setup();
            /* End:   Bugfix for FTPAN-116 (IC-12886) */

            HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_OFF_DEBUG_PIN);  //DEBUG!
        }

        return;
    }

    field_state_cnt = 0;
}

/**
 * @brief Function for enablinge hight precision clock and start eveluating fieldlost event.
 */
static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state)
{
    if (!m_field_on)
    {
        HAL_NFC_DEBUG_PIN_SET(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!
        nrf_drv_clock_hfclk_request(&m_clock_handler_item);

        NRF_TIMER4->TASKS_CLEAR = 1;
        NRF_TIMER4->TASKS_START = 1;
        field_state_cnt = 0;

        HAL_NFC_DEBUG_PIN_CLEAR(HAL_NFC_HCLOCK_ON_DEBUG_PIN);  //DEBUG!
    }
    m_field_on = true;
}

/**
 * @brief Function for resume the NFCT to initialized state after software's reset.
 */
static inline void hal_nfc_re_setup(void)
{
    hal_nfc_common_hw_setup();

    NRF_LOG_INFO("Reinitialize");
}
#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

#endif // NFC_T2T_HAL_ENABLED

and it should work. This is the full fix, so there are some log functions that are changed as well.

You can just replace these two lines in hal_nfc_t2t.c to apply the actual fix (Pic to the left is the fixed version).

 

Best regards,

Simon

[Dash]

Simon,

Thank you. Yes that solves the problem.

After further investigation I discovered it was not enabling the softdevice that caused problems but calling advertising_start which caused the NFC to stop working properly.

After I posted the initial question I found the same patch that you shared described in this post. Applying the patch given in this post solved my problem (since I am using an nRF52840 DK version 0.12.0).

You stated, "This should be fixed in SDK 15.1 and newer". Can you verify that fix is in SDK 15.2? I will upgrade to SDK 15.2 if it resolves this problem.

Does the newer SDK also apply the fix for the Type 4 tag?   

Thank you.