This one is throwing me for a loop. We have a very basic NFC component in our firmware that serves up a static NDEF file and wakes the MCU from a system_off state.55045.prj.conf
We have been occasionally encountering an issue where NFC doesn't seem to work and won't work again until the board is reset. After spending more time debugging and attempting to reproduce the issue, it seems that a lockup of some kind occurs when "weak" NFC activity takes place. For example, moving the reader around too far from the device to properly read it. It works reliably if you put the phone NFC reader close to the NFC antenna and read it normally, but if you're off target or too far away, it won't read and won't function otherwise (including any NFC read attempts) until a reset. There are no log messages indicating any activity when this happens, nor are there any hard faults/resets. It simply appears to stop until reset by the reset pin or a POR.
The closest thing we got to a log response is the following snippet, but we only saw this once. Every other time we reproduced it there were no log messages.
[00:00:04.400,695] <dbg> nfc_platform: nfc_platform_event_handler: Field detected [00:00:04.401,519] <inf> NRFX_NFCT: Reinitialize [00:00:04.401,519] <dbg> nfc_platform: nfc_platform_event_handler: Field lost [00:00:04.401,580] <inf> NFC: Field OFF [00:00:04.941,619] <dbg> nfc_platform: nfc_platform_event_handler: Field detected [00:00:04.942,535] <inf> NRFX_NFCT: Reinitialize [00:00:04.942,565] <dbg> nfc_platform: nfc_platform_event_handler: Field lost [00:00:04.942,626] <inf> NFC: Field OFF [00:00:04.947,479] <dbg> nfc_platform: nfc_platform_event_handler: Field detected [00:00:04.965,698] <inf> NRFX_NFCT: Reinitialize [00:00:04.965,728] <dbg> nfc_platform: nfc_platform_event_handler: Field lost [00:00:04.965,789] <inf> NFC: Field OFF [00:00:04.970,642] <dbg> nfc_platform: nfc_platform_event_handler: Field detected [00:00:05.002,655] <inf> NRFX_NFCT: Reinitialize [00:00:05.002,655] <dbg> nfc_platform: nfc_platform_event_handler: Field lost [00:00:05.002,716] <inf> NFC: Field OFF
We're using SDK 2.6.0. nfc code file is attached as well as configs. Thank you!
/************************************************************************//**
*
* \file ssum_nfc.c
*
* \addtogroup ssum_nfc ssum_nfc
* \{
*
* \brief
*
* \note
*
* \author dylanjackson (Geocene, Inc)
* \date 2024-03-19
*
****************************************************************************/
/****************************************************************************
* INCLUDE FILES *
****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <nfc/ndef/msg.h>
#include <nfc_t4t_lib.h>
#include <nfc/t4t/ndef_file.h>
#include <nfc/ndef/uri_msg.h>
#include <zephyr/drivers/gpio.h>
#include <hal/nrf_gpio.h>
#include "ssum_nfc.h"
#include "ssum_nvs.h"
#include "ssum_ble_man.h"
#include "mission_ctrl.h"
#include <zephyr/logging/log.h>
/****************************************************************************
* PRIVATE TYPES and DEFINITIONS *
****************************************************************************/
#define SERIAL_HEX_CHARS 6 // 3 bytes -> 6 hex characters
#define SUDO_BUTTON_NODE DT_ALIAS(sudobutton)
#if !DT_NODE_HAS_STATUS(SUDO_BUTTON_NODE, okay)
#define DEV_BOARD
#endif
/****************************************************************************
* PRIVATE DATA *
****************************************************************************/
static const uint8_t m_base_url[] =
{'g', 'e', 'o', 'c', 'e', 'n', 'e', ':', '/', '/','S','S','U','M','-'};
static uint8_t ndef_msg_buf[CONFIG_NDEF_FILE_SIZE]; /**< Buffer for NDEF file. */
#ifndef DEV_BOARD
static const struct gpio_dt_spec sudo_button = GPIO_DT_SPEC_GET_OR(SUDO_BUTTON_NODE, gpios, {0});
static struct gpio_callback sudo_button_cb_data;
#endif
/****************************************************************************
* PRIVATE FUNCTION DECLARATIONS *
****************************************************************************/
static void nfc_callback(void *context, nfc_t4t_event_t event,
const uint8_t *data, size_t data_length, uint32_t flags);
#ifndef DEV_BOARD
static void sudo_button_cb(const struct device *dev, struct gpio_callback *cb, uint32_t pins);
#endif
static int ndef_file_init(uint8_t *buff, uint32_t *size);
/****************************************************************************
* STATIC DECLARATIONS *
****************************************************************************/
LOG_MODULE_REGISTER(NFC, LOG_LEVEL_DBG);
/****************************************************************************
* EXPORTED FUNCTION DEFINITIONS *
****************************************************************************/
int ssum_nfc_init(void)
{
/* Set up NFC */
int err = nfc_t4t_setup(nfc_callback, NULL);
if (err < 0)
{
LOG_ERR("Cannot setup t4t library!");
}
/* Load NDEF message from the flash file. */
uint32_t size = 0;
if (ndef_file_init(ndef_msg_buf, &size) < 0)
{
LOG_ERR("Cannot init NDEF file!");
}
/* Run Read-Write mode for Type 4 Tag platform */
if (nfc_t4t_ndef_staticpayload_set(ndef_msg_buf, sizeof(ndef_msg_buf)) < 0)
{
LOG_ERR("Cannot set payload!");
}
#ifndef DEV_BOARD
/* Set up sudo button */
if (!gpio_is_ready_dt(&sudo_button))
{
LOG_ERR("Error: %s is not ready\n", sudo_button.port->name);
}
else
{
gpio_pin_configure_dt(&sudo_button, GPIO_INPUT);
gpio_pin_interrupt_configure_dt(&sudo_button, GPIO_INT_EDGE_TO_ACTIVE);
gpio_init_callback(&sudo_button_cb_data, sudo_button_cb, BIT(sudo_button.pin));
gpio_add_callback(sudo_button.port, &sudo_button_cb_data);
}
#endif
/* Start sensing NFC field */
if (nfc_t4t_emulation_start() < 0)
{
LOG_ERR("Cannot start emulation!");
}
return err;
}
/****************************************************************************
* PRIVATE FUNCTION DEFINITIONS *
****************************************************************************/
static void nfc_callback(void *context, nfc_t4t_event_t event,
const uint8_t *data, size_t data_length, uint32_t flags)
{
ARG_UNUSED(context);
ARG_UNUSED(data);
ARG_UNUSED(data_length);
switch (event) {
case NFC_T4T_EVENT_FIELD_ON:
LOG_INF("Field ON");
break;
case NFC_T4T_EVENT_FIELD_OFF:
LOG_INF("Field OFF");
break;
case NFC_T4T_EVENT_NDEF_READ:
LOG_INF("NDEF Read");
if (mission_ctrl_get_state() != MISSION_SHIP_STATE)
{
mission_ctrl_sudo_boop_detected();
}
break;
default:
break;
}
}
#ifndef DEV_BOARD
static void sudo_button_cb(const struct device *dev, struct gpio_callback *cb, uint32_t pins)
{
if (mission_ctrl_get_state() != MISSION_SHIP_STATE && pins & BIT(sudo_button.pin))
{
mission_ctrl_sudo_boop_detected();
}
}
#endif
static int ndef_file_init(uint8_t *buff, uint32_t *size)
{
int err;
uint8_t url_size = sizeof(m_base_url);
char msg[url_size + SERIAL_HEX_CHARS + 1]; // add a space for null-term
memcpy(msg, m_base_url, url_size);
// Read the device serial
uint64_t id = ssum_nvs_get_device_id();
// Tack only the last 3 bytes (6 hex chars) onto the end of the NFC message
sprintf(&msg[url_size], "%06X", (uint32_t)(id & 0x00FFFFFF));
LOG_INF("NFC msg: '%s'", msg);
uint32_t ndef_size = nfc_t4t_ndef_file_msg_size_get(*size);
err = nfc_ndef_uri_msg_encode(NFC_URI_NONE,
msg, sizeof(msg) - 1, // don't pass in null term as it messes with the NFC read on the app
nfc_t4t_ndef_file_msg_get(buff), &ndef_size);
if (err < 0) {
LOG_ERR("Cannot encode URI!");
}
err = nfc_t4t_ndef_file_encode(buff, &ndef_size);
*size = ndef_size;
if (err < 0) {
LOG_ERR("Cannot encode file!");
}
return err;
}
/************************************************************************//**
* \brief
* \param
* \return
****************************************************************************/
/** \}*/
