Fix clang-tidy: rename static constexpr to UPPER_SNAKE_CASE

Replace heap-allocated std::vector constants with static constexpr
std::array in MIFARE Classic and Ultralight write operations across
pn532, pn7150, and pn7160 components.

Changes:
- Convert write_mifare_classic_block_ and write_mifare_ultralight_page_
  signatures from std::vector<uint8_t>& to const uint8_t*/size_t
- Replace 24 constant 16-byte vectors in format functions with
  static constexpr std::array (data now lives in flash/rodata)
- Replace 3 constant 4-byte blank_data vectors with static constexpr
  std::array
- Eliminate per-iteration vector copies in write_tag loops by passing
  pointers directly into the encoded buffer

esphome/components/pn532/pn532.h

@@ -76,7 +76,7 @@ class PN532 : public PollingComponent {
 
   std::unique_ptr<nfc::NfcTag> read_mifare_classic_tag_(nfc::NfcTagUid &uid);
   bool read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  bool write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
+  bool write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
   bool auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key);
   bool format_mifare_classic_mifare_(nfc::NfcTagUid &uid);
   bool format_mifare_classic_ndef_(nfc::NfcTagUid &uid);
@@ -88,7 +88,7 @@ class PN532 : public PollingComponent {
   uint16_t read_mifare_ultralight_capacity_();
   bool find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                     uint8_t &message_start_index);
-  bool write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
+  bool write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
   bool write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message);
   bool clean_mifare_ultralight_();
 

esphome/components/pn532/pn532_mifare_classic.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <memory>
 
 #include "pn532.h"
@@ -106,10 +107,10 @@ bool PN532::auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, u
 }
 
 bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
-  std::vector<uint8_t> blank_buffer(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> trailer_buffer(
-      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   bool error = false;
 
@@ -118,20 +119,20 @@ bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
       continue;
     }
     if (block != 0) {
-      if (!this->write_mifare_classic_block_(block, blank_buffer)) {
+      if (!this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
         error = true;
       }
     }
-    if (!this->write_mifare_classic_block_(block + 1, blank_buffer)) {
+    if (!this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 1);
       error = true;
     }
-    if (!this->write_mifare_classic_block_(block + 2, blank_buffer)) {
+    if (!this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 2);
       error = true;
     }
-    if (!this->write_mifare_classic_block_(block + 3, trailer_buffer)) {
+    if (!this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size())) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 3);
       error = true;
     }
@@ -141,28 +142,28 @@ bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
 }
 
 bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
-  std::vector<uint8_t> empty_ndef_message(
-      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> blank_block(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> block_1_data(
-      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_2_data(
-      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_3_trailer(
-      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
-  std::vector<uint8_t> ndef_trailer(
-      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
+      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
+      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
+      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
+      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
+      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   if (!this->auth_mifare_classic_block_(uid, 0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY)) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting!");
     return false;
   }
-  if (!this->write_mifare_classic_block_(1, block_1_data))
+  if (!this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()))
     return false;
-  if (!this->write_mifare_classic_block_(2, block_2_data))
+  if (!this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()))
     return false;
-  if (!this->write_mifare_classic_block_(3, block_3_trailer))
+  if (!this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()))
     return false;
 
   ESP_LOGD(TAG, "Sector 0 formatted to NDEF");
@@ -172,36 +173,36 @@ bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
       return false;
     }
     if (block == 4) {
-      if (!this->write_mifare_classic_block_(block, empty_ndef_message)) {
+      if (!this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size())) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
       }
     } else {
-      if (!this->write_mifare_classic_block_(block, blank_block)) {
+      if (!this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
       }
     }
-    if (!this->write_mifare_classic_block_(block + 1, blank_block)) {
+    if (!this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 1);
     }
-    if (!this->write_mifare_classic_block_(block + 2, blank_block)) {
+    if (!this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 2);
     }
-    if (!this->write_mifare_classic_block_(block + 3, ndef_trailer)) {
+    if (!this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size())) {
       ESP_LOGE(TAG, "Unable to write trailer block %d", block + 3);
     }
   }
   return true;
 }
 
-bool PN532::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
-  std::vector<uint8_t> data({
+bool PN532::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
+  std::vector<uint8_t> cmd({
       PN532_COMMAND_INDATAEXCHANGE,
       0x01,  // One card
       nfc::MIFARE_CMD_WRITE,
       block_num,
   });
-  data.insert(data.end(), write_data.begin(), write_data.end());
-  if (!this->write_command_(data)) {
+  cmd.insert(cmd.end(), data, data + len);
+  if (!this->write_command_(cmd)) {
     ESP_LOGE(TAG, "Error writing block %d", block_num);
     return false;
   }
@@ -243,8 +244,7 @@ bool PN532::write_mifare_classic_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *mes
       }
     }
 
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
-    if (!this->write_mifare_classic_block_(current_block, data)) {
+    if (!this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE)) {
       return false;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn532/pn532_mifare_ultralight.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <memory>
 
 #include "pn532.h"
@@ -143,8 +144,7 @@ bool PN532::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
-    if (!this->write_mifare_ultralight_page_(current_page, data)) {
+    if (!this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE)) {
       return false;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -157,25 +157,25 @@ bool PN532::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (!this->write_mifare_ultralight_page_(i, blank_data)) {
+    if (!this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size())) {
       return false;
     }
   }
   return true;
 }
 
-bool PN532::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
-  std::vector<uint8_t> data({
+bool PN532::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
+  std::vector<uint8_t> cmd({
       PN532_COMMAND_INDATAEXCHANGE,
       0x01,  // One card
       nfc::MIFARE_CMD_WRITE_ULTRALIGHT,
       page_num,
   });
-  data.insert(data.end(), write_data.begin(), write_data.end());
-  if (!this->write_command_(data)) {
+  cmd.insert(cmd.end(), write_data, write_data + len);
+  if (!this->write_command_(cmd)) {
     ESP_LOGE(TAG, "Error writing page %u", page_num);
     return false;
   }

esphome/components/pn7150/pn7150.h

@@ -236,7 +236,7 @@ class PN7150 : public nfc::Nfcc, public Component {
 
   uint8_t read_mifare_classic_tag_(nfc::NfcTag &tag);
   uint8_t read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  uint8_t write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
+  uint8_t write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
   uint8_t auth_mifare_classic_block_(uint8_t block_num, uint8_t key_num, const uint8_t *key);
   uint8_t sect_to_auth_(uint8_t block_num);
   uint8_t format_mifare_classic_mifare_();
@@ -250,7 +250,7 @@ class PN7150 : public nfc::Nfcc, public Component {
   uint16_t read_mifare_ultralight_capacity_();
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
-  uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
+  uint8_t write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
   uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 

esphome/components/pn7150/pn7150_mifare_classic.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <memory>
 
 #include "pn7150.h"
@@ -139,10 +140,10 @@ uint8_t PN7150::sect_to_auth_(const uint8_t block_num) {
 }
 
 uint8_t PN7150::format_mifare_classic_mifare_() {
-  std::vector<uint8_t> blank_buffer(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> trailer_buffer(
-      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   auto status = nfc::STATUS_OK;
 
@@ -151,20 +152,20 @@ uint8_t PN7150::format_mifare_classic_mifare_() {
       continue;
     }
     if (block != 0) {
-      if (this->write_mifare_classic_block_(block, blank_buffer) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, blank_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, blank_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, trailer_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -174,30 +175,30 @@ uint8_t PN7150::format_mifare_classic_mifare_() {
 }
 
 uint8_t PN7150::format_mifare_classic_ndef_() {
-  std::vector<uint8_t> empty_ndef_message(
-      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> blank_block(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> block_1_data(
-      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_2_data(
-      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_3_trailer(
-      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
-  std::vector<uint8_t> ndef_trailer(
-      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
+      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
+      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
+      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
+      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
+      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   if (this->auth_mifare_classic_block_(0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY) != nfc::STATUS_OK) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting");
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(1, block_1_data) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(2, block_2_data) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(3, block_3_trailer) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
 
@@ -210,25 +211,26 @@ uint8_t PN7150::format_mifare_classic_ndef_() {
       return nfc::STATUS_FAILED;
     }
     if (block == 4) {
-      if (this->write_mifare_classic_block_(block, empty_ndef_message) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size()) !=
+          nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     } else {
-      if (this->write_mifare_classic_block_(block, blank_block) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, blank_block) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, blank_block) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, ndef_trailer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write trailer block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -236,7 +238,7 @@ uint8_t PN7150::format_mifare_classic_ndef_() {
   return status;
 }
 
-uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
+uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, {XCHG_DATA_OID, nfc::MIFARE_CMD_WRITE, block_num});
 
@@ -248,7 +250,7 @@ uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8
   }
   // write command part two
   tx.set_payload({XCHG_DATA_OID});
-  tx.get_message().insert(tx.get_message().end(), write_data.begin(), write_data.end());
+  tx.get_message().insert(tx.get_message().end(), data, data + len);
 
   ESP_LOGVV(TAG, "Write XCHG_DATA_REQ 2: %s", nfc::format_bytes_to(buf, tx.get_message()));
   if (this->transceive_(tx, rx, NFCC_TAG_WRITE_TIMEOUT) != nfc::STATUS_OK) {
@@ -294,8 +296,8 @@ uint8_t PN7150::write_mifare_classic_tag_(const std::shared_ptr<nfc::NdefMessage
       }
     }
 
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
-    if (this->write_mifare_classic_block_(current_block, data) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE) !=
+        nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn7150/pn7150_mifare_ultralight.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <cinttypes>
 #include <memory>
 
@@ -144,8 +145,8 @@ uint8_t PN7150::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::sha
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
-    if (this->write_mifare_ultralight_page_(current_page, data) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) !=
+        nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -158,19 +159,19 @@ uint8_t PN7150::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (this->write_mifare_ultralight_page_(i, blank_data) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size()) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
   }
   return nfc::STATUS_OK;
 }
 
-uint8_t PN7150::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
+uint8_t PN7150::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
   std::vector<uint8_t> payload = {nfc::MIFARE_CMD_WRITE_ULTRALIGHT, page_num};
-  payload.insert(payload.end(), write_data.begin(), write_data.end());
+  payload.insert(payload.end(), write_data, write_data + len);
 
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, payload);

esphome/components/pn7160/pn7160.h

@@ -253,7 +253,7 @@ class PN7160 : public nfc::Nfcc, public Component {
 
   uint8_t read_mifare_classic_tag_(nfc::NfcTag &tag);
   uint8_t read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  uint8_t write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
+  uint8_t write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
   uint8_t auth_mifare_classic_block_(uint8_t block_num, uint8_t key_num, const uint8_t *key);
   uint8_t sect_to_auth_(uint8_t block_num);
   uint8_t format_mifare_classic_mifare_();
@@ -267,7 +267,7 @@ class PN7160 : public nfc::Nfcc, public Component {
   uint16_t read_mifare_ultralight_capacity_();
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
-  uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
+  uint8_t write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
   uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 

esphome/components/pn7160/pn7160_mifare_classic.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <memory>
 
 #include "pn7160.h"
@@ -139,10 +140,10 @@ uint8_t PN7160::sect_to_auth_(const uint8_t block_num) {
 }
 
 uint8_t PN7160::format_mifare_classic_mifare_() {
-  std::vector<uint8_t> blank_buffer(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> trailer_buffer(
-      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   auto status = nfc::STATUS_OK;
 
@@ -151,20 +152,20 @@ uint8_t PN7160::format_mifare_classic_mifare_() {
       continue;
     }
     if (block != 0) {
-      if (this->write_mifare_classic_block_(block, blank_buffer) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, blank_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, blank_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, trailer_buffer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -174,30 +175,30 @@ uint8_t PN7160::format_mifare_classic_mifare_() {
 }
 
 uint8_t PN7160::format_mifare_classic_ndef_() {
-  std::vector<uint8_t> empty_ndef_message(
-      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> blank_block(
-      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
-  std::vector<uint8_t> block_1_data(
-      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_2_data(
-      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
-  std::vector<uint8_t> block_3_trailer(
-      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
-  std::vector<uint8_t> ndef_trailer(
-      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
+      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
+      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
+      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
+      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
+      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
   if (this->auth_mifare_classic_block_(0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY) != nfc::STATUS_OK) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting");
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(1, block_1_data) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(2, block_2_data) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(3, block_3_trailer) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
 
@@ -210,25 +211,26 @@ uint8_t PN7160::format_mifare_classic_ndef_() {
       return nfc::STATUS_FAILED;
     }
     if (block == 4) {
-      if (this->write_mifare_classic_block_(block, empty_ndef_message) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size()) !=
+          nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     } else {
-      if (this->write_mifare_classic_block_(block, blank_block) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, blank_block) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, blank_block) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, ndef_trailer) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size()) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write trailer block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -236,7 +238,7 @@ uint8_t PN7160::format_mifare_classic_ndef_() {
   return status;
 }
 
-uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
+uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, {XCHG_DATA_OID, nfc::MIFARE_CMD_WRITE, block_num});
   char buf[nfc::FORMAT_BYTES_BUFFER_SIZE];
@@ -248,7 +250,7 @@ uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8
   }
   // write command part two
   tx.set_payload({XCHG_DATA_OID});
-  tx.get_message().insert(tx.get_message().end(), write_data.begin(), write_data.end());
+  tx.get_message().insert(tx.get_message().end(), data, data + len);
 
   ESP_LOGVV(TAG, "Write XCHG_DATA_REQ 2: %s", nfc::format_bytes_to(buf, tx.get_message()));
   if (this->transceive_(tx, rx, NFCC_TAG_WRITE_TIMEOUT) != nfc::STATUS_OK) {
@@ -294,8 +296,8 @@ uint8_t PN7160::write_mifare_classic_tag_(const std::shared_ptr<nfc::NdefMessage
       }
     }
 
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
-    if (this->write_mifare_classic_block_(current_block, data) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE) !=
+        nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn7160/pn7160_mifare_ultralight.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <cinttypes>
 #include <memory>
 
@@ -144,8 +145,8 @@ uint8_t PN7160::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::sha
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
-    if (this->write_mifare_ultralight_page_(current_page, data) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) !=
+        nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -158,19 +159,19 @@ uint8_t PN7160::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
+  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (this->write_mifare_ultralight_page_(i, blank_data) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size()) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
   }
   return nfc::STATUS_OK;
 }
 
-uint8_t PN7160::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
+uint8_t PN7160::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
   std::vector<uint8_t> payload = {nfc::MIFARE_CMD_WRITE_ULTRALIGHT, page_num};
-  payload.insert(payload.end(), write_data.begin(), write_data.end());
+  payload.insert(payload.end(), write_data, write_data + len);
 
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, payload);

esphome/components/usb_host/usb_host.h

@@ -148,6 +148,7 @@ class USBClient : public Component {
   EventPool<UsbEvent, USB_EVENT_QUEUE_SIZE> event_pool;
 
  protected:
+  void handle_open_state_();
   TransferRequest *get_trq_();  // Lock-free allocation using atomic bitmask (multi-consumer safe)
   virtual void disconnect();
   virtual void on_connected() {}

esphome/components/usb_host/usb_host_client.cpp

@@ -9,6 +9,7 @@
 #include <cinttypes>
 #include <cstring>
 #include <atomic>
+#include <span>
 namespace esphome {
 namespace usb_host {
 
@@ -142,18 +143,23 @@ static void usb_client_print_config_descriptor(const usb_config_desc_t *cfg_desc
   } while (next_desc != NULL);
 }
 #endif
-static std::string get_descriptor_string(const usb_str_desc_t *desc) {
-  char buffer[256];
-  if (desc == nullptr)
+// USB string descriptors: bLength (uint8_t, max 255) includes the 2-byte header (bLength and bDescriptorType).
+// Character count = (bLength - 2) / 2, max 126 chars + null terminator.
+static constexpr size_t DESC_STRING_BUF_SIZE = 128;
+
+static const char *get_descriptor_string(const usb_str_desc_t *desc, std::span<char, DESC_STRING_BUF_SIZE> buffer) {
+  if (desc == nullptr || desc->bLength < 2)
     return "(unspecified)";
-  char *p = buffer;
-  for (int i = 0; i != desc->bLength / 2; i++) {
+  int char_count = (desc->bLength - 2) / 2;
+  char *p = buffer.data();
+  char *end = p + buffer.size() - 1;
+  for (int i = 0; i != char_count && p < end; i++) {
     auto c = desc->wData[i];
     if (c < 0x100)
       *p++ = static_cast<char>(c);
   }
   *p = '\0';
-  return {buffer};
+  return buffer.data();
 }
 
 // CALLBACK CONTEXT: USB task (called from usb_host_client_handle_events in USB task)
@@ -259,60 +265,63 @@ void USBClient::loop() {
     ESP_LOGW(TAG, "Dropped %u USB events due to queue overflow", dropped);
   }
 
-  switch (this->state_) {
-    case USB_CLIENT_OPEN: {
-      int err;
-      ESP_LOGD(TAG, "Open device %d", this->device_addr_);
-      err = usb_host_device_open(this->handle_, this->device_addr_, &this->device_handle_);
-      if (err != ESP_OK) {
-        ESP_LOGW(TAG, "Device open failed: %s", esp_err_to_name(err));
-        this->state_ = USB_CLIENT_INIT;
-        break;
-      }
-      ESP_LOGD(TAG, "Get descriptor device %d", this->device_addr_);
-      const usb_device_desc_t *desc;
-      err = usb_host_get_device_descriptor(this->device_handle_, &desc);
-      if (err != ESP_OK) {
-        ESP_LOGW(TAG, "Device get_desc failed: %s", esp_err_to_name(err));
-        this->disconnect();
-      } else {
-        ESP_LOGD(TAG, "Device descriptor: vid %X pid %X", desc->idVendor, desc->idProduct);
-        if (desc->idVendor == this->vid_ && desc->idProduct == this->pid_ || this->vid_ == 0 && this->pid_ == 0) {
-          usb_device_info_t dev_info;
-          err = usb_host_device_info(this->device_handle_, &dev_info);
-          if (err != ESP_OK) {
-            ESP_LOGW(TAG, "Device info failed: %s", esp_err_to_name(err));
-            this->disconnect();
-            break;
-          }
-          this->state_ = USB_CLIENT_CONNECTED;
-          ESP_LOGD(TAG, "Device connected: Manuf: %s; Prod: %s; Serial: %s",
-                   get_descriptor_string(dev_info.str_desc_manufacturer).c_str(),
-                   get_descriptor_string(dev_info.str_desc_product).c_str(),
-                   get_descriptor_string(dev_info.str_desc_serial_num).c_str());
+  if (this->state_ == USB_CLIENT_OPEN) {
+    this->handle_open_state_();
+  }
+}
+
+void USBClient::handle_open_state_() {
+  int err;
+  ESP_LOGD(TAG, "Open device %d", this->device_addr_);
+  err = usb_host_device_open(this->handle_, this->device_addr_, &this->device_handle_);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "Device open failed: %s", esp_err_to_name(err));
+    this->state_ = USB_CLIENT_INIT;
+    return;
+  }
+  ESP_LOGD(TAG, "Get descriptor device %d", this->device_addr_);
+  const usb_device_desc_t *desc;
+  err = usb_host_get_device_descriptor(this->device_handle_, &desc);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "Device get_desc failed: %s", esp_err_to_name(err));
+    this->disconnect();
+    return;
+  }
+  ESP_LOGD(TAG, "Device descriptor: vid %X pid %X", desc->idVendor, desc->idProduct);
+  if (desc->idVendor != this->vid_ || desc->idProduct != this->pid_) {
+    if (this->vid_ != 0 || this->pid_ != 0) {
+      ESP_LOGD(TAG, "Not our device, closing");
+      this->disconnect();
+      return;
+    }
+  }
+  usb_device_info_t dev_info;
+  err = usb_host_device_info(this->device_handle_, &dev_info);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "Device info failed: %s", esp_err_to_name(err));
+    this->disconnect();
+    return;
+  }
+  this->state_ = USB_CLIENT_CONNECTED;
+  char buf_manuf[DESC_STRING_BUF_SIZE];
+  char buf_product[DESC_STRING_BUF_SIZE];
+  char buf_serial[DESC_STRING_BUF_SIZE];
+  ESP_LOGD(TAG, "Device connected: Manuf: %s; Prod: %s; Serial: %s",
+           get_descriptor_string(dev_info.str_desc_manufacturer, buf_manuf),
+           get_descriptor_string(dev_info.str_desc_product, buf_product),
+           get_descriptor_string(dev_info.str_desc_serial_num, buf_serial));
 
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
-          const usb_device_desc_t *device_desc;
-          err = usb_host_get_device_descriptor(this->device_handle_, &device_desc);
-          if (err == ESP_OK)
-            usb_client_print_device_descriptor(device_desc);
-          const usb_config_desc_t *config_desc;
-          err = usb_host_get_active_config_descriptor(this->device_handle_, &config_desc);
-          if (err == ESP_OK)
-            usb_client_print_config_descriptor(config_desc, nullptr);
+  const usb_device_desc_t *device_desc;
+  err = usb_host_get_device_descriptor(this->device_handle_, &device_desc);
+  if (err == ESP_OK)
+    usb_client_print_device_descriptor(device_desc);
+  const usb_config_desc_t *config_desc;
+  err = usb_host_get_active_config_descriptor(this->device_handle_, &config_desc);
+  if (err == ESP_OK)
+    usb_client_print_config_descriptor(config_desc, nullptr);
 #endif
-          this->on_connected();
-        } else {
-          ESP_LOGD(TAG, "Not our device, closing");
-          this->disconnect();
-        }
-      }
-      break;
-    }
-
-    default:
-      break;
-  }
+  this->on_connected();
 }
 
 void USBClient::on_opened(uint8_t addr) {