Hi,
I'm trying to modify the text_record example for NFC data transfer to transmit a numeric payload (working on an nrf52832). The original example transmits "Hello World!" with its language code, and I got that flashed just fine. I'm modifying the code to transmit an ID (uint8), a timestamp (YYYYMMDD) and a value (uint8).
The main problem is adding an extra two variables to the structs. I've made project-local copies of the header files "msg.h" and "record.h", and my own header file which is based on the header "text_rec.h". I've attached all my code to this ticket.
The error I'm currently getting is
c:\nordic\attempt1\src\attempt1.h:59:7: error: expected identifier before numeric constant
59 | 0, \
And I'm not sure how to fix this, since the 0's in this structure were in the original code, but I did add two more for the new variables...
All the attached code is in the same directory, with one dependency on a header I haven't edited.
Hope this all makes sense! Thank you for your help.
#ifndef NFC_NDEF_ATTEMPT1_H_
#define NFC_NDEF_ATTEMPT1_H_
#include <zephyr/types.h>
#include "record.h"
#ifdef __cplusplus
extern "C" {
#endif
struct nfc_ndef_text_rec_payload {
/** Pointer to the ID. */
uint8_t const *id;
/** Length of the ID. */
uint8_t id_length;
/** Pointer to the timestamp. */
uint8_t const *time;
/** Length of the timestamp. */
uint32_t time_length;
/** Pointer to the data. */
uint8_t const *data;
/** Length of the data. */
uint32_t data_length;
};
int nfc_ndef_text_rec_payload_encode(
struct nfc_ndef_text_rec_payload *nfc_rec_text_payload_desc,
uint8_t *buff,
uint32_t *len);
extern const uint8_t nfc_ndef_text_rec_type_field[];
#define NFC_NDEF_TEXT_REC_TYPE_LENGTH 1
#define NFC_NDEF_TEXT_RECORD_DESC_DEF(name, \
id_arg, \
id_len_arg, \
time_arg, \
time_len_arg, \
data_arg, \
data_len_arg) \
struct nfc_ndef_text_rec_payload name##_nfc_ndef_text_rec_payload = \
{ \
.id_length = id_len_arg, \
.id = id_arg, \
.time_length = time_len_arg, \
.time = time_arg, \
.data_length = data_len_arg, \
.data = data_arg, \
}; \
NFC_NDEF_GENERIC_RECORD_DESC_DEF(name, \
0, \
0, \
0, \
0, \
nfc_ndef_text_rec_type_field, \
NFC_NDEF_TEXT_REC_TYPE_LENGTH, \
nfc_ndef_text_rec_payload_encode, \
&(name##_nfc_ndef_text_rec_payload))
#define NFC_NDEF_TEXT_RECORD_DESC(name) NFC_NDEF_GENERIC_RECORD_DESC(name)
#ifdef __cplusplus
}
#endif
#endif /* NFC_NDEF_ATTEMPT1_H_ */
// main.c
#include <zephyr.h>
// #include <sys/reboot.h'>
#include <dk_buttons_and_leds.h>
#include <nfc_t2t_lib.h>
#include "msg.h"
#include "attempt1.h"
#define NFC_FIELD_LED DK_LED1
#define NDEF_BUF_SIZE 128
#define MAX_REC_COUNT 1
//strain reading
static const uint32_t strainreading = 289319;
static const uint8_t timestamp[] = {'2', '0', '2', '2', '0', '4', '2', '7'};
static const uint32_t identifier = 1;
//buffer to hold NFC NDEF
static uint8_t ndef_buf[NDEF_BUF_SIZE];
//callback function
static void nfc_callback(void *context,
nfc_t2t_event_t event,
const uint8_t *data,
size_t data_length)
{
ARG_UNUSED(context);
ARG_UNUSED(data);
ARG_UNUSED(data_length);
switch (event) {
case NFC_T2T_EVENT_FIELD_ON:
dk_set_led_on(NFC_FIELD_LED);
break;
case NFC_T2T_EVENT_FIELD_OFF:
dk_set_led_off(NFC_FIELD_LED);
break;
default:
break;
}
}
//encoding the NDEF message
static int encode(uint8_t *buffer, uint32_t *len)
{
int err;
NFC_NDEF_TEXT_RECORD_DESC_DEF(nfc_payload_1,
identifier,
sizeof(identifier),
timestamp,
sizeof(timestamp),
strainreading,
sizeof(strainreading));
NFC_NDEF_MSG_DEF(nfc_text_msg, MAX_REC_COUNT);
/* Add text records to NDEF text message */
err = nfc_ndef_msg_record_add(&NFC_NDEF_MSG(nfc_text_msg),
&NFC_NDEF_TEXT_RECORD_DESC(nfc_payload_1));
if (err < 0) {
printk("Cannot add first record!\n");
return err;
}
return err;
}
int main(void)
{
uint32_t len = sizeof(ndef_buf);
printk("Attempt 1\n");
/* Configure LED-pins as outputs */
if (dk_leds_init() < 0) {
printk("Cannot init LEDs!\n");
}
/* Set up NFC */
if (nfc_t2t_setup(nfc_callback, NULL) < 0) {
printk("Cannot setup NFC T2T library!\n");
}
//encode
/* Encode welcome message */
if (encode(ndef_buf, &len) < 0) {
printk("Cannot encode message!\n");
}
/* Set created message as the NFC payload */
if (nfc_t2t_payload_set(ndef_buf, len) < 0) {
printk("Cannot set payload!\n");
}
/* Start sensing NFC field */
if (nfc_t2t_emulation_start() < 0) {
printk("Cannot start emulation!\n");
}
printk("NFC configuration done\n");
return 0;
}#ifndef NFC_NDEF_RECORD_H_
#define NFC_NDEF_RECORD_H_
#include <zephyr/types.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef int (*payload_constructor_t)(void *payload_descriptor,
uint8_t *buffer,
uint32_t *len);
struct nfc_ndef_record_desc {
uint8_t id_length;
uint8_t const *id;
uint8_t time_length;
uint8_t const *time;
uint8_t type_length;
uint8_t const *type;
payload_constructor_t payload_constructor;
void *payload_descriptor;
};
enum nfc_ndef_record_location {
NDEF_FIRST_RECORD = 0x80, /**< First record. */
NDEF_MIDDLE_RECORD = 0x00, /**< Middle record. */
NDEF_LAST_RECORD = 0x100, /**< Last record. */
NDEF_LONE_RECORD = 0x180 /**< Only one record in the message. */
};
#define NDEF_RECORD_LOCATION_MASK (NDEF_LONE_RECORD)
struct nfc_ndef_bin_payload_desc {
uint8_t const *payload; /**< Pointer to the buffer with the data. */
uint32_t payload_length; /**< Length of data in bytes. */
};
#define NFC_NDEF_GENERIC_RECORD_DESC_DEF(name, \
id_arg,\
id_length,\
time_arg,\
time_length,\
type_arg,\
type_length, \
payload_constructor_arg,\
payload_descriptor_arg) \
struct nfc_ndef_record_desc name##_ndef_generic_record_desc = \
{ \
.id_length = id_length, \
.id = id_arg, \
.time_length = time_length, \
.time = time_arg, \
.type_length = type_length, \
.type = type_arg, \
.payload_constructor = \
(payload_constructor_t)payload_constructor_arg, \
.payload_descriptor = (void *) payload_descriptor_arg \
}
#define NFC_NDEF_GENERIC_RECORD_DESC(name) (name##_ndef_generic_record_desc)
#define NFC_NDEF_RECORD_BIN_DATA_DEF(name, \
id_arg, \
id_len, \
time_arg,\
time_len,\
type_arg, \
type_len, \
payload_arg, \
payload_len) \
struct nfc_ndef_bin_payload_desc name##_nfc_ndef_bin_payload_desc = \
{ \
.payload = payload_arg, \
.payload_length = payload_len \
}; \
\
struct nfc_ndef_record_desc name##_nfc_ndef_bin_record_desc = \
{ \
.id_length = id_len, \
.id = id_arg, \
.time_length = time_len, \
.time = time_arg, \
.type_length = type_len, \
.type = type_arg, \
.payload_constructor = \
(payload_constructor_t) nfc_ndef_bin_payload_memcopy, \
.payload_descriptor = \
(void *) &name##_nfc_ndef_bin_payload_desc \
}
#define NFC_NDEF_RECORD_BIN_DATA(name) (name##_nfc_ndef_bin_record_desc)
#define NFC_NDEF_BIN_PAYLOAD_DESC(name) (name##_nfc_ndef_bin_payload_desc)
int nfc_ndef_record_encode(struct nfc_ndef_record_desc const *ndef_record_desc,
enum nfc_ndef_record_location const record_location,
uint8_t *record_buffer,
uint32_t *record_len);
int nfc_ndef_bin_payload_memcopy(
struct nfc_ndef_bin_payload_desc *payload_descriptor,
uint8_t *buffer,
uint32_t *len);
#ifdef __cplusplus
}
#endif
#endif /* NFC_NDEF_RECORD_H_ */#ifndef NFC_NDEF_MSG_H_
#define NFC_NDEF_MSG_H_
#include <zephyr/types.h>
#include "record.h"
#ifdef __cplusplus
extern "C" {
#endif
struct nfc_ndef_msg_desc {
/** Pointer to an array of pointers to NDEF record descriptors. */
struct nfc_ndef_record_desc const **record;
/** Number of elements in the allocated record array, which defines
* the maximum number of records within the NDEF message.
*/
uint32_t max_record_count;
/** Number of records in the NDEF message. */
uint32_t record_count;
};
int nfc_ndef_msg_encode(struct nfc_ndef_msg_desc const *ndef_msg_desc,
uint8_t *msg_buffer,
uint32_t *msg_len);
void nfc_ndef_msg_clear(struct nfc_ndef_msg_desc *msg);
int nfc_ndef_msg_record_add(struct nfc_ndef_msg_desc *msg,
struct nfc_ndef_record_desc const *record);
#define NFC_NDEF_MSG_DEF(name, max_record_cnt) \
struct nfc_ndef_record_desc const \
*name##_nfc_ndef_record_desc_array[max_record_cnt]; \
struct nfc_ndef_msg_desc name##_nfc_ndef_msg_desc = \
{ \
.record = name##_nfc_ndef_record_desc_array, \
.max_record_count = max_record_cnt, \
.record_count = 0 \
}
#define NFC_NDEF_MSG(name) (name##_nfc_ndef_msg_desc)
#define NFC_NDEF_NESTED_NDEF_MSG_RECORD_DEF(name, \
id_arg, \
id_len, \
time_arg, \
time_len, \
type_arg, \
type_len, \
nested_message) \
struct nfc_ndef_record_desc name##_ndef_record_nested_desc = \
{ \
.id_length = id_len, \
.id = id_arg, \
.time_length = time_len, \
.time = time_arg, \
.type_length = type_len, \
.type = type_arg, \
.payload_constructor = \
(payload_constructor_t)(nfc_ndef_msg_encode), \
.payload_descriptor = (void *) (nested_message) \
}
#define NFC_NDEF_NESTED_NDEF_MSG_RECORD(name) (name##_ndef_record_nested_desc)
#ifdef __cplusplus
}
#endif
#endif /* NFC_NDEF_MSG_H_*/
