feat(nfc): emit example.com URI for native phone reading

ql-application/threadx/interface/custom_app/nfc.c

@@ -49,7 +49,6 @@ static volatile u32 g_nfc_tx_mode_deadline = 0;
 #define NFC_TYPE2_READ_SIZE         16
 #define NFC_TYPE2_MEMORY_SIZE       160
 #define NFC_TYPE2_NDEF_OFFSET       16
-#define NFC_IMEI_DIGITS             15
 
 #define NFC_IRQ_TX                  0x40
 #define NFC_IRQ_RX                  0x20
@@ -173,37 +172,11 @@ static u8 nfc_card_emulation_send_frame(const u8 *frame, u8 length)
 
 static void nfc_type2_build_ndef(void)
 {
-    char device_id[32] = {0};
+    static const char uri_suffix[] = "example.com/";
-    char serial_number[32] = {0};
+    size_t uri_len = sizeof(uri_suffix) - 1;
-    char imei[32] = {0};
-    char json[128];
-    int json_len;
     u8 *ndef;
     u8 record_len;
 
-    if (hal_os_get_device_id(device_id) != 0) {
-        strcpy(device_id, "unknown");
-    }
-    if (hal_os_get_device_sn(serial_number) != 0) {
-        strcpy(serial_number, "unknown");
-    }
-    if (ql_dev_get_imei(imei, sizeof(imei)) != QL_DEV_SUCCESS ||
-        imei[0] == '\0') {
-        strcpy(imei, "unknown");
-    } else {
-        imei[NFC_IMEI_DIGITS] = '\0';
-    }
-
-    json_len = snprintf(json, sizeof(json),
-                        "{\"device_id\":\"%s\",\"serial_number\":\"%s\","
-                        "\"imei\":\"%s\"}",
-                        device_id, serial_number, imei);
-    if (json_len < 0) {
-        json_len = 0;
-    } else if (json_len >= (int)sizeof(json)) {
-        json_len = sizeof(json) - 1;
-    }
-
     memset(nfc_type2_memory, 0, sizeof(nfc_type2_memory));
 
     /* Static UID/manufacturer pages followed by a read-only Type 2 CC. */
@@ -217,20 +190,18 @@ static void nfc_type2_build_ndef(void)
     nfc_type2_memory[15] = 0x0F; /* Read-only access. */
 
     ndef = &nfc_type2_memory[NFC_TYPE2_NDEF_OFFSET];
-    record_len = (u8)(7 + json_len);
+    record_len = (u8)(5 + uri_len);
     ndef[0] = 0x03;                  /* NDEF Message TLV. */
     ndef[1] = record_len;
     ndef[2] = 0xD1;                  /* MB, ME, SR, TNF well-known. */
     ndef[3] = 0x01;                  /* Type length. */
-    ndef[4] = (u8)(3 + json_len);    /* Text status/lang plus JSON. */
+    ndef[4] = (u8)(1 + uri_len);    /* URI prefix code plus suffix. */
-    ndef[5] = 'T';
+    ndef[5] = 'U';                   /* NFC Forum URI record. */
-    ndef[6] = 0x02;                  /* UTF-8, language length 2. */
+    ndef[6] = 0x04;                  /* URI prefix: https:// */
-    ndef[7] = 'e';
+    memcpy(&ndef[7], uri_suffix, uri_len);
-    ndef[8] = 'n';
+    ndef[7 + uri_len] = 0xFE;        /* Terminator TLV. */
-    memcpy(&ndef[9], json, json_len);
-    ndef[9 + json_len] = 0xFE;       /* Terminator TLV. */
 
-    printf("NFC Type 2 NDEF: %s\r\n", json);
+    printf("NFC Type 2 NDEF URI: https://%s\r\n", uri_suffix);
 }
 
 static void nfc_type2_read_pages(u8 start_page, u8 *response)