Merge remote-tracking branch 'upstream/fast-millis-esp32' into integration

2026-09-03 19:46:02 +00:00 · 2026-04-21 04:55:03 +02:00
parent 574bdc9a00 02f77cce79
commit 00da5d0a26
37 changed files with 955 additions and 554 deletions
@@ -1 +1 @@
-88bba93420f1dbc8c64a555c631195a8dc9544e6dc98ae45ac04978206c01bd7
+ba69d5a66178882091cd943a22d1df9e461bff19bda4e312150650a39143ab8b
@@ -339,7 +339,7 @@ jobs:
          echo "binary=$BINARY" >> $GITHUB_OUTPUT

      - name: Run CodSpeed benchmarks
-        uses: CodSpeedHQ/action@db35df748deb45fdef0960669f57d627c1956c30 # v4
+        uses: CodSpeedHQ/action@658a901452bb54c799643e060733b7afe9121b8d # v4.14.0
        with:
          run: ${{ steps.build.outputs.binary }}
          mode: simulation
@@ -2,6 +2,8 @@
 #include <cstdio>
 #include <cstring>

+#include "esphome/core/alloc_helpers.h"
+
 namespace esphome {
 namespace anova {

@@ -105,14 +107,14 @@ void AnovaCodec::decode(const uint8_t *data, uint16_t length) {
    }
    case READ_TARGET_TEMPERATURE:
    case SET_TARGET_TEMPERATURE: {
-      this->target_temp_ = parse_number<float>(str_until(buf, '\r')).value_or(0.0f);
+      this->target_temp_ = parse_number<float>(str_until(buf, '\r')).value_or(0.0f);  // NOLINT
      if (this->fahrenheit_)
        this->target_temp_ = ftoc(this->target_temp_);
      this->has_target_temp_ = true;
      break;
    }
    case READ_CURRENT_TEMPERATURE: {
-      this->current_temp_ = parse_number<float>(str_until(buf, '\r')).value_or(0.0f);
+      this->current_temp_ = parse_number<float>(str_until(buf, '\r')).value_or(0.0f);  // NOLINT
      if (this->fahrenheit_)
        this->current_temp_ = ftoc(this->current_temp_);
      this->has_current_temp_ = true;
@@ -0,0 +1,97 @@
+#include "epaper_spi_ssd1683.h"
+
+#include <algorithm>
+
+#include "esphome/core/log.h"
+
+namespace esphome::epaper_spi {
+static constexpr const char *const TAG = "epaper_spi.mono";
+
+void EPaperSSD1683::refresh_screen(bool partial) {
+  ESP_LOGV(TAG, "Refresh screen");
+  this->cmd_data(0x3C, {partial ? (uint8_t) 0x80 : (uint8_t) 0x01});
+  // On partial update, set red RAM to inverse to remove BW ghosting
+  this->cmd_data(0x21, {partial ? (uint8_t) 0x80 : (uint8_t) 0x40, (uint8_t) 0x00});
+  // Set full update to 0xD7 for fast update, 0xF7 for normal
+  // Fast update flashes less and draws sooner but is in busy state for the same amount of time
+  // Manufacturer recommends not using fast update all the time, TODO expose this to the user
+  this->cmd_data(0x22, {partial ? (uint8_t) 0xFC : (uint8_t) 0xF7});
+  this->command(0x20);
+}
+
+// Puts the display into deep sleep mode 1, only way to get out is to reset the display
+// Mode 1 retains RAM while sleeping, necessary for future partial and window updates
+void EPaperSSD1683::deep_sleep() {
+  if (this->is_using_partial_update_()) {
+    ESP_LOGV(TAG, "Deep sleep mode 1");
+    this->cmd_data(0x10, {0x01});  // deep sleep, retain RAM
+  } else {
+    ESP_LOGV(TAG, "Deep sleep mode 2");
+    this->cmd_data(0x10, {0x03});  // deep sleep, lose RAM
+  }
+}
+
+void EPaperSSD1683::set_window() {
+  // if not using partial update, the display will go into deep sleep mode 2, so must rewrite entire
+  // buffer since the display RAM will not retain contents
+  if (!this->is_using_partial_update_()) {
+    this->x_low_ = 0;
+    this->x_high_ = this->width_;
+    this->y_low_ = 0;
+    this->y_high_ = this->height_;
+  }
+
+  // round x-coordinates to byte boundaries
+  this->x_low_ /= 8;
+  this->x_high_ += 7;
+  this->x_high_ /= 8;
+
+  this->cmd_data(0x44, {(uint8_t) this->x_low_, (uint8_t) (this->x_high_ - 1)});
+  this->cmd_data(0x45, {(uint8_t) this->y_low_, (uint8_t) (this->y_low_ / 256), (uint8_t) (this->y_high_ - 1),
+                        (uint8_t) ((this->y_high_ - 1) / 256)});
+  this->cmd_data(0x4E, {(uint8_t) this->x_low_});
+  this->cmd_data(0x4F, {(uint8_t) this->y_low_, (uint8_t) (this->y_low_ / 256)});
+}
+
+bool HOT EPaperSSD1683::transfer_data() {
+  auto start_time = millis();
+  if (this->current_data_index_ == 0) {
+    if (this->send_red_) {
+      // round to byte boundaries
+      this->set_window();
+    }
+    // for monochrome, we need to send red on every refresh to prevent dirty pixels
+    // when doing a partial refresh
+    this->command(this->send_red_ ? 0x26 : 0x24);
+    this->current_data_index_ = this->y_low_;  // actually current line
+  }
+  size_t row_length = this->x_high_ - this->x_low_;
+  FixedVector<uint8_t> bytes_to_send{};
+  bytes_to_send.init(row_length);
+  ESP_LOGV(TAG, "Writing %u bytes at line %zu at %ums", row_length, this->current_data_index_, (unsigned) millis());
+  this->start_data_();
+  while (this->current_data_index_ != this->y_high_) {
+    size_t data_idx = this->current_data_index_ * this->row_width_ + this->x_low_;
+    for (size_t i = 0; i != row_length; i++) {
+      bytes_to_send[i] = this->buffer_[data_idx++];
+    }
+    ++this->current_data_index_;
+    this->write_array(&bytes_to_send.front(), row_length);  // NOLINT
+    if (millis() - start_time > MAX_TRANSFER_TIME) {
+      // Let the main loop run and come back next loop
+      this->disable();
+      return false;
+    }
+  }
+
+  this->disable();
+  this->current_data_index_ = 0;
+  if (this->send_red_) {
+    this->send_red_ = false;
+    return false;
+  }
+  this->send_red_ = true;
+  return true;
+}
+
+}  // namespace esphome::epaper_spi
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "epaper_spi_mono.h"
+
+namespace esphome::epaper_spi {
+/**
+ * A class for Solomon SSD1683 epaper displays.
+ */
+class EPaperSSD1683 : public EPaperMono {
+ public:
+  EPaperSSD1683(const char *name, uint16_t width, uint16_t height, const uint8_t *init_sequence,
+                size_t init_sequence_length)
+      : EPaperMono(name, width, height, init_sequence, init_sequence_length) {}
+
+ protected:
+  void refresh_screen(bool partial) override;
+  void deep_sleep() override;
+  void set_window() override;
+  bool transfer_data() override;
+};
+
+}  // namespace esphome::epaper_spi
@@ -0,0 +1,27 @@
+from esphome.const import CONF_DATA_RATE
+
+from . import EpaperModel
+
+
+class SSD1683(EpaperModel):
+    def __init__(self, name, class_name="EPaperSSD1683", data_rate="20MHz", **defaults):
+        defaults[CONF_DATA_RATE] = data_rate
+        super().__init__(name, class_name, **defaults)
+
+    # fmt: off
+    def get_init_sequence(self, config: dict):
+        _width, height = self.get_dimensions(config)
+        return (
+            (0x01, (height - 1) % 256, (height - 1) // 256, 0x00),    # Set column gate limit
+            (0x18, 0x80),    # Select internal Temp sensor
+            (0x11, 0x03),      # Set transform
+        )
+
+
+ssd1683 = SSD1683("ssd1683")
+
+goodisplay_gdey042t81 = ssd1683.extend(
+    "goodisplay-gdey042t81-4.2",
+    width=400,
+    height=300,
+)
@@ -22,7 +22,7 @@ void HttpRequestComponent::dump_config() {
 }

 std::string HttpContainer::get_response_header(const std::string &header_name) {
-  auto lower = str_lower_case(header_name);
+  auto lower = str_lower_case(header_name);  // NOLINT
  for (const auto &entry : this->response_headers_) {
    if (entry.name == lower) {
      ESP_LOGD(TAG, "Header with name %s found with value %s", lower.c_str(), entry.value.c_str());
@@ -11,6 +11,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/defines.h"
+#include "esphome/core/alloc_helpers.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"

@@ -400,7 +401,7 @@ class HttpRequestComponent : public Component {
    std::vector<std::string> lower;
    lower.reserve(collect_headers.size());
    for (const auto &h : collect_headers) {
-      lower.push_back(str_lower_case(h));
+      lower.push_back(str_lower_case(h));  // NOLINT
    }
    return this->perform(url, method, body, request_headers, lower);
  }
@@ -415,7 +416,7 @@ class HttpRequestComponent : public Component {
    std::vector<std::string> lower;
    lower.reserve(collect_headers.size());
    for (const auto &h : collect_headers) {
-      lower.push_back(str_lower_case(h));
+      lower.push_back(str_lower_case(h));  // NOLINT
    }
    return this->perform(url, method, body, std::vector<Header>(request_headers.begin(), request_headers.end()), lower);
  }
@@ -161,7 +161,7 @@ std::shared_ptr<HttpContainer> HttpRequestArduino::perform(const std::string &ur
  container->response_headers_.clear();
  auto header_count = container->client_.headers();
  for (int i = 0; i < header_count; i++) {
-    const std::string header_name = str_lower_case(container->client_.headerName(i).c_str());
+    const std::string header_name = str_lower_case(container->client_.headerName(i).c_str());  // NOLINT
    if (should_collect_header(lower_case_collect_headers, header_name)) {
      std::string header_value = container->client_.header(i).c_str();
      ESP_LOGD(TAG, "Received response header, name: %s, value: %s", header_name.c_str(), header_value.c_str());
@@ -115,7 +115,7 @@ std::shared_ptr<HttpContainer> HttpRequestHost::perform(const std::string &url,
  container->content_length = container->response_body_.size();
  for (auto header : response.headers) {
    ESP_LOGD(TAG, "Header: %s: %s", header.first.c_str(), header.second.c_str());
-    auto lower_name = str_lower_case(header.first);
+    auto lower_name = str_lower_case(header.first);  // NOLINT
    if (should_collect_header(lower_case_collect_headers, lower_name)) {
      container->response_headers_.push_back({lower_name, header.second});
    }
@@ -38,7 +38,7 @@ esp_err_t HttpRequestIDF::http_event_handler(esp_http_client_event_t *evt) {

  switch (evt->event_id) {
    case HTTP_EVENT_ON_HEADER: {
-      const std::string header_name = str_lower_case(evt->header_key);
+      const std::string header_name = str_lower_case(evt->header_key);  // NOLINT
      if (should_collect_header(user_data->lower_case_collect_headers, header_name)) {
        const std::string header_value = evt->header_value;
        ESP_LOGD(TAG, "Received response header, name: %s, value: %s", header_name.c_str(), header_value.c_str());
@@ -756,7 +756,7 @@ async def write_image(config, all_frames=False):
            for col in range(width):
                encoder.encode(pixels[row * width + col])
            encoder.end_row()
-        encoder.end_image()
+    encoder.end_image()

    rhs = [HexInt(x) for x in encoder.data]
    prog_arr = cg.progmem_array(config[CONF_RAW_DATA_ID], rhs)
@@ -89,10 +89,12 @@
                      id: hello_world_label_
                      text: "Hello World!"
                      align: center
-            - obj:
+            - container:
                id: hello_world_qrcode_
                outline_width: 0
                border_width: 0
+                height: 100
+                width: 100
                hidden: !lambda |-
                    return lv_obj_get_width(lv_screen_active()) < 300 && lv_obj_get_height(lv_screen_active()) < 400;
                widgets:
@@ -88,6 +88,12 @@ inline void lv_obj_set_style_bitmap_mask_src(lv_obj_t *obj, image::Image *image,
 inline void lv_obj_set_style_bg_image_src(lv_obj_t *obj, image::Image *image, lv_style_selector_t selector) {
  ::lv_obj_set_style_bg_image_src(obj, image->get_lv_image_dsc(), selector);
 }
+inline void lv_style_set_bg_image_src(lv_style_t *style, image::Image *image) {
+  ::lv_style_set_bg_image_src(style, image->get_lv_image_dsc());
+}
+inline void lv_style_set_bitmap_mask_src(lv_style_t *style, image::Image *image) {
+  ::lv_style_set_bitmap_mask_src(style, image->get_lv_image_dsc());
+}
 #endif  // USE_LVGL_IMAGE
 #ifdef USE_LVGL_ANIMIMG
 inline void lv_animimg_set_src(lv_obj_t *img, std::vector<image::Image *> images) {
@@ -52,19 +52,23 @@ class KeyboardType(WidgetType):
        if mode := config.get(CONF_MODE):
            await w.set_property(CONF_MODE, await KEYBOARD_MODES.process(mode))
        if textarea := config.get(CONF_TEXTAREA):
-            # If a textarea is configured, it must be generated before the keyboard can attach it.
-            # If not yet configured, defer the attachment code.
+            if not is_widget_completed(textarea):
+                # Can only happen for an initial config, where the keyboard is configured before the
+                # textarea, so it's ok to always emit into the global context
+                async def add_textarea():
+                    async with LvContext():
+                        await w.set_property(
+                            CONF_TEXTAREA,
+                            (await get_widgets(config, CONF_TEXTAREA))[0].obj,
+                        )

-            async def add_textarea():
-                async with LvContext():
-                    await w.set_property(
-                        CONF_TEXTAREA, (await get_widgets(config, CONF_TEXTAREA))[0].obj
-                    )
-
-            if is_widget_completed(textarea):
-                await add_textarea()
-            else:
                CORE.add_job(add_textarea)
+            else:
+                # Handles updates in automations, and properly ordered initial config. Code is generated
+                # into the enclosing context (main or lambda)
+                await w.set_property(
+                    CONF_TEXTAREA, (await get_widgets(config, CONF_TEXTAREA))[0].obj
+                )


 keyboard_spec = KeyboardType()
@@ -454,12 +454,12 @@ async def to_code(config):
    # Pin esp-nn for stable future builds (esp-tflite-micro depends on esp-nn)
    esp32.add_idf_component(name="espressif/esp-nn", ref="1.1.2")

+    esp32.add_idf_component(name="esphome/esp-micro-speech-features", ref="1.2.3")
+
    cg.add_build_flag("-DTF_LITE_STATIC_MEMORY")
    cg.add_build_flag("-DTF_LITE_DISABLE_X86_NEON")
    cg.add_build_flag("-DESP_NN")

-    cg.add_library("kahrendt/ESPMicroSpeechFeatures", "1.1.0")
-
    if vad_model := config.get(CONF_VAD):
        cg.add_define("USE_MICRO_WAKE_WORD_VAD")

@@ -0,0 +1,29 @@
+from esphome.components.mipi import DriverChip
+import esphome.config_validation as cv
+
+# Standalone display
+# Product page: https://www.seeedstudio.com/reTerminal-D1001-p-6729.html
+DriverChip(
+    "SEEED-RETERMINAL-D1001",
+    height=1280,
+    width=800,
+    hsync_back_porch=20,
+    hsync_pulse_width=20,
+    hsync_front_porch=40,
+    vsync_back_porch=12,
+    vsync_pulse_width=4,
+    vsync_front_porch=30,
+    pclk_frequency="80MHz",
+    lane_bit_rate="1.5Gbps",
+    swap_xy=cv.UNDEFINED,
+    color_order="RGB",
+    enable_pin=[{"xl9535": None, "number": 0}, {"xl9535": None, "number": 7}],
+    reset_pin={"xl9535": None, "number": 2},
+    initsequence=(
+        (0xE0, 0x00),
+        (0xE1, 0x93),
+        (0xE2, 0x65),
+        (0xE3, 0xF8),
+        (0x80, 0x01),
+    ),
+)
@@ -0,0 +1,51 @@
+from esphome.components.mipi import DriverChip
+from esphome.config_validation import UNDEFINED
+
+# fmt: off
+sunton = DriverChip(
+    "ESP32-8048S070",
+    swap_xy=UNDEFINED,
+    initsequence=(),
+    width=800,
+    height=480,
+    pclk_frequency="12.5MHz",
+    de_pin=41,
+    hsync_pin=39,
+    vsync_pin=40,
+    pclk_pin=42,
+    hsync_pulse_width=30,
+    hsync_back_porch=16,
+    hsync_front_porch=210,
+    vsync_pulse_width=13,
+    vsync_back_porch=10,
+    vsync_front_porch=22,
+    data_pins={
+        "red": [14, 21, 47, 48, 45],
+        "green": [9, 46, 3, 8, 16, 1],
+        "blue": [15, 7, 6, 5, 4],
+    },
+)
+
+sunton.extend(
+    "ESP32-8048S050",
+    swap_xy=UNDEFINED,
+    initsequence=(),
+    width=800,
+    height=480,
+    pclk_frequency="16MHz",
+    de_pin=40,
+    hsync_pin=39,
+    vsync_pin=41,
+    pclk_pin=42,
+    hsync_back_porch=8,
+    hsync_front_porch=8,
+    hsync_pulse_width=4,
+    vsync_back_porch=8,
+    vsync_front_porch=8,
+    vsync_pulse_width=4,
+    data_pins={
+        "red": [45, 48, 47, 21, 14],
+        "green": [5, 6, 7, 15, 16, 4],
+        "blue": [8, 3, 46, 9, 1],
+    },
+)
@@ -5,6 +5,29 @@ namespace esphome::modbus::helpers {

 static const char *const TAG = "modbus_helpers";

+static size_t required_payload_size(SensorValueType sensor_value_type) {
+  switch (sensor_value_type) {
+    case SensorValueType::U_WORD:
+    case SensorValueType::S_WORD:
+      return 2;
+    case SensorValueType::U_DWORD:
+    case SensorValueType::FP32:
+    case SensorValueType::U_DWORD_R:
+    case SensorValueType::FP32_R:
+    case SensorValueType::S_DWORD:
+    case SensorValueType::S_DWORD_R:
+      return 4;
+    case SensorValueType::U_QWORD:
+    case SensorValueType::S_QWORD:
+    case SensorValueType::U_QWORD_R:
+    case SensorValueType::S_QWORD_R:
+      return 8;
+    case SensorValueType::RAW:
+    default:
+      return 0;
+  }
+}
+
 void number_to_payload(std::vector<uint16_t> &data, int64_t value, SensorValueType value_type) {
  switch (value_type) {
    case SensorValueType::U_WORD:
@@ -47,93 +70,70 @@ int64_t payload_to_number(const std::vector<uint8_t> &data, SensorValueType sens
                          uint32_t bitmask) {
  int64_t value = 0;  // int64_t because it can hold signed and unsigned 32 bits

-  if (offset > data.size()) {
-    ESP_LOGE(TAG, "not enough data for value");
+  // Validate offset against the buffer for all types, including RAW/unsupported, so
+  // a malformed or misconfigured frame still produces an error log.
+  if (static_cast<size_t>(offset) > data.size()) {
+    ESP_LOGE(TAG, "not enough data for value type=%u offset=%u size=%zu", static_cast<unsigned int>(sensor_value_type),
+             static_cast<unsigned int>(offset), data.size());
+    return value;
+  }
+
+  const size_t required_size = required_payload_size(sensor_value_type);
+  if (required_size == 0) {
+    return value;
+  }
+
+  if (data.size() - offset < required_size) {
+    ESP_LOGE(TAG, "not enough data for value type=%u offset=%u size=%zu required=%zu",
+             static_cast<unsigned int>(sensor_value_type), static_cast<unsigned int>(offset), data.size(),
+             required_size);
    return value;
  }

-  size_t size = data.size() - offset;
-  bool error = false;
  switch (sensor_value_type) {
    case SensorValueType::U_WORD:
-      if (size >= 2) {
-        value = mask_and_shift_by_rightbit(get_data<uint16_t>(data, offset),
-                                           bitmask);  // default is 0xFFFF ;
-      } else {
-        error = true;
-      }
+      value = mask_and_shift_by_rightbit(get_data<uint16_t>(data, offset), bitmask);  // default is 0xFFFF ;
      break;
    case SensorValueType::U_DWORD:
    case SensorValueType::FP32:
-      if (size >= 4) {
-        value = get_data<uint32_t>(data, offset);
-        value = mask_and_shift_by_rightbit((uint32_t) value, bitmask);
-      } else {
-        error = true;
-      }
+      value = get_data<uint32_t>(data, offset);
+      value = mask_and_shift_by_rightbit((uint32_t) value, bitmask);
      break;
    case SensorValueType::U_DWORD_R:
    case SensorValueType::FP32_R:
-      if (size >= 4) {
-        value = get_data<uint32_t>(data, offset);
-        value = static_cast<uint32_t>(value & 0xFFFF) << 16 | (value & 0xFFFF0000) >> 16;
-        value = mask_and_shift_by_rightbit((uint32_t) value, bitmask);
-      } else {
-        error = true;
-      }
+      value = get_data<uint32_t>(data, offset);
+      value = static_cast<uint32_t>(value & 0xFFFF) << 16 | (value & 0xFFFF0000) >> 16;
+      value = mask_and_shift_by_rightbit((uint32_t) value, bitmask);
      break;
    case SensorValueType::S_WORD:
-      if (size >= 2) {
-        value = mask_and_shift_by_rightbit(get_data<int16_t>(data, offset),
-                                           bitmask);  // default is 0xFFFF ;
-      } else {
-        error = true;
-      }
+      value = mask_and_shift_by_rightbit(get_data<int16_t>(data, offset), bitmask);  // default is 0xFFFF ;
      break;
    case SensorValueType::S_DWORD:
-      if (size >= 4) {
-        value = mask_and_shift_by_rightbit(get_data<int32_t>(data, offset), bitmask);
-      } else {
-        error = true;
-      }
+      value = mask_and_shift_by_rightbit(get_data<int32_t>(data, offset), bitmask);
      break;
    case SensorValueType::S_DWORD_R: {
-      if (size >= 4) {
-        value = get_data<uint32_t>(data, offset);
-        // Currently the high word is at the low position
-        // the sign bit is therefore at low before the switch
-        uint32_t sign_bit = (value & 0x8000) << 16;
-        value = mask_and_shift_by_rightbit(
-            static_cast<int32_t>(((value & 0x7FFF) << 16 | (value & 0xFFFF0000) >> 16) | sign_bit), bitmask);
-      } else {
-        error = true;
-      }
+      value = get_data<uint32_t>(data, offset);
+      // Currently the high word is at the low position
+      // the sign bit is therefore at low before the switch
+      uint32_t sign_bit = (value & 0x8000) << 16;
+      value = mask_and_shift_by_rightbit(
+          static_cast<int32_t>(((value & 0x7FFF) << 16 | (value & 0xFFFF0000) >> 16) | sign_bit), bitmask);
    } break;
    case SensorValueType::U_QWORD:
    case SensorValueType::S_QWORD:
      // Ignore bitmask for QWORD
-      if (size >= 8) {
-        value = get_data<uint64_t>(data, offset);
-      } else {
-        error = true;
-      }
+      value = get_data<uint64_t>(data, offset);
      break;
    case SensorValueType::U_QWORD_R:
    case SensorValueType::S_QWORD_R: {
      // Ignore bitmask for QWORD
-      if (size >= 8) {
-        uint64_t tmp = get_data<uint64_t>(data, offset);
-        value = (tmp << 48) | (tmp >> 48) | ((tmp & 0xFFFF0000) << 16) | ((tmp >> 16) & 0xFFFF0000);
-      } else {
-        error = true;
-      }
+      uint64_t tmp = get_data<uint64_t>(data, offset);
+      value = (tmp << 48) | (tmp >> 48) | ((tmp & 0xFFFF0000) << 16) | ((tmp >> 16) & 0xFFFF0000);
    } break;
    case SensorValueType::RAW:
    default:
      break;
  }
-  if (error)
-    ESP_LOGE(TAG, "not enough data for value");
  return value;
 }
 }  // namespace esphome::modbus::helpers
@@ -294,57 +294,59 @@ void Rtttl::play(std::string rtttl) {
  }
  ESP_LOGD(TAG, "Playing song %.*s", (int) this->position_, this->rtttl_.c_str());

-  // Get default duration
-  this->position_ = this->rtttl_.find("d=", this->position_);
-  if (this->position_ == std::string::npos) {
-    ESP_LOGE(TAG, "Missing 'd='");
-    return;
-  }
-  this->position_ += 2;
-  num = this->get_integer_();
-  if (num == 1 || num == 2 || num == 4 || num == 8 || num == 16 || num == 32) {
-    this->default_note_denominator_ = num;
-  } else {
-    ESP_LOGE(TAG, "Invalid default duration: %d", num);
-    return;
-  }
-
-  // Get default octave
-  this->position_ = this->rtttl_.find("o=", this->position_);
-  if (this->position_ == std::string::npos) {
-    ESP_LOGE(TAG, "Missing 'o=");
-    return;
-  }
-  this->position_ += 2;
-  num = this->get_integer_();
-  if (num >= MIN_OCTAVE && num <= MAX_OCTAVE) {
-    this->default_octave_ = num;
-  } else {
-    ESP_LOGE(TAG, "Invalid default octave: %d", num);
-    return;
-  }
-
-  // Get BPM
-  this->position_ = this->rtttl_.find("b=", this->position_);
-  if (this->position_ == std::string::npos) {
-    ESP_LOGE(TAG, "Missing b=");
-    return;
-  }
-  this->position_ += 2;
-  num = this->get_integer_();
-  if (num >= 4) {  // Below 4 is not realistic and would cause a integer overflow
-    bpm = num;
-  } else {
-    ESP_LOGE(TAG, "Invalid BPM: %d", num);
-    return;
-  }
-
-  this->position_ = this->rtttl_.find(':', this->position_);
-  if (this->position_ == std::string::npos) {
+  size_t name_end_position = this->position_;
+  size_t control_end = this->rtttl_.find(':', name_end_position + 1);
+  if (control_end == std::string::npos) {
    ESP_LOGE(TAG, "Missing second ':'");
    return;
  }
-  this->position_++;
+
+  // Get default duration
+  size_t pos = this->rtttl_.find("d=", name_end_position);
+  if (pos == std::string::npos || pos >= control_end) {
+    ESP_LOGW(TAG, "Missing 'd='; use default duration %d", this->default_note_denominator_);
+  } else {
+    this->position_ = pos + 2;
+    num = this->get_integer_();
+    if (num == 1 || num == 2 || num == 4 || num == 8 || num == 16 || num == 32) {
+      this->default_note_denominator_ = num;
+    } else {
+      ESP_LOGE(TAG, "Invalid default duration: %d", num);
+      return;
+    }
+  }
+
+  // Get default octave
+  pos = this->rtttl_.find("o=", name_end_position);
+  if (pos == std::string::npos || pos >= control_end) {
+    ESP_LOGW(TAG, "Missing 'o='; use default octave %d", this->default_octave_);
+  } else {
+    this->position_ = pos + 2;
+    num = this->get_integer_();
+    if (num >= MIN_OCTAVE && num <= MAX_OCTAVE) {
+      this->default_octave_ = num;
+    } else {
+      ESP_LOGE(TAG, "Invalid default octave: %d", num);
+      return;
+    }
+  }
+
+  // Get BPM
+  pos = this->rtttl_.find("b=", name_end_position);
+  if (pos == std::string::npos || pos >= control_end) {
+    ESP_LOGW(TAG, "Missing 'b='; use default BPM %d", bpm);
+  } else {
+    this->position_ = pos + 2;
+    num = this->get_integer_();
+    if (num >= 4) {  // Below 4 is not realistic and would cause a integer overflow
+      bpm = num;
+    } else {
+      ESP_LOGE(TAG, "Invalid BPM: %d", num);
+      return;
+    }
+  }
+
+  this->position_ = control_end + 1;

  // BPM usually expresses the number of quarter notes per minute
  this->wholenote_duration_ = 60 * 1000L * 4 / bpm;  // This is the time for whole note (in milliseconds)
@@ -0,0 +1,229 @@
+#include "esphome/core/alloc_helpers.h"
+
+#include "esphome/core/helpers.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstdarg>
+#include <cstdio>
+#include <cstring>
+#include <string>
+
+namespace esphome {
+
+// --- String helpers ---
+
+std::string str_truncate(const std::string &str, size_t length) {
+  return str.length() > length ? str.substr(0, length) : str;
+}
+
+std::string str_until(const char *str, char ch) {
+  const char *pos = strchr(str, ch);
+  return pos == nullptr ? std::string(str) : std::string(str, pos - str);
+}
+std::string str_until(const std::string &str, char ch) { return str.substr(0, str.find(ch)); }
+
+// wrapper around std::transform to run safely on functions from the ctype.h header
+// see https://en.cppreference.com/w/cpp/string/byte/toupper#Notes
+template<int (*fn)(int)> std::string str_ctype_transform(const std::string &str) {
+  std::string result;
+  result.resize(str.length());
+  std::transform(str.begin(), str.end(), result.begin(), [](unsigned char ch) { return fn(ch); });
+  return result;
+}
+std::string str_lower_case(const std::string &str) { return str_ctype_transform<std::tolower>(str); }
+
+std::string str_upper_case(const std::string &str) {
+  std::string result;
+  result.resize(str.length());
+  std::transform(str.begin(), str.end(), result.begin(), [](unsigned char ch) { return std::toupper(ch); });
+  return result;
+}
+
+std::string str_snake_case(const std::string &str) {
+  std::string result = str;
+  for (char &c : result) {
+    c = to_snake_case_char(c);
+  }
+  return result;
+}
+
+std::string str_sanitize(const std::string &str) {
+  std::string result;
+  result.resize(str.size());
+  str_sanitize_to(&result[0], str.size() + 1, str.c_str());
+  return result;
+}
+
+std::string str_snprintf(const char *fmt, size_t len, ...) {
+  std::string str;
+  va_list args;
+
+  str.resize(len);
+  va_start(args, len);
+  size_t out_length = vsnprintf(&str[0], len + 1, fmt, args);
+  va_end(args);
+
+  if (out_length < len)
+    str.resize(out_length);
+
+  return str;
+}
+
+std::string str_sprintf(const char *fmt, ...) {
+  std::string str;
+  va_list args;
+
+  va_start(args, fmt);
+  size_t length = vsnprintf(nullptr, 0, fmt, args);
+  va_end(args);
+
+  str.resize(length);
+  va_start(args, fmt);
+  vsnprintf(&str[0], length + 1, fmt, args);
+  va_end(args);
+
+  return str;
+}
+
+// --- Value formatting helpers ---
+
+std::string value_accuracy_to_string(float value, int8_t accuracy_decimals) {
+  char buf[VALUE_ACCURACY_MAX_LEN];
+  value_accuracy_to_buf(buf, value, accuracy_decimals);
+  return std::string(buf);
+}
+
+// --- Base64 helpers ---
+
+static constexpr const char *BASE64_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                            "abcdefghijklmnopqrstuvwxyz"
+                                            "0123456789+/";
+
+// Encode 3 input bytes to 4 base64 characters, append 'count' to ret.
+static inline void base64_encode_triple(const char *char_array_3, int count, std::string &ret) {
+  char char_array_4[4];
+  char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+  char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+  char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+  char_array_4[3] = char_array_3[2] & 0x3f;
+
+  for (int j = 0; j < count; j++)
+    ret += BASE64_CHARS[static_cast<uint8_t>(char_array_4[j])];
+}
+
+std::string base64_encode(const std::vector<uint8_t> &buf) { return base64_encode(buf.data(), buf.size()); }
+
+std::string base64_encode(const uint8_t *buf, size_t buf_len) {
+  std::string ret;
+  int i = 0;
+  char char_array_3[3];
+
+  while (buf_len--) {
+    char_array_3[i++] = *(buf++);
+    if (i == 3) {
+      base64_encode_triple(char_array_3, 4, ret);
+      i = 0;
+    }
+  }
+
+  if (i) {
+    for (int j = i; j < 3; j++)
+      char_array_3[j] = '\0';
+
+    base64_encode_triple(char_array_3, i + 1, ret);
+
+    while ((i++ < 3))
+      ret += '=';
+  }
+
+  return ret;
+}
+
+std::vector<uint8_t> base64_decode(const std::string &encoded_string) {
+  // Calculate maximum decoded size: every 4 base64 chars = 3 bytes
+  size_t max_len = ((encoded_string.size() + 3) / 4) * 3;
+  std::vector<uint8_t> ret(max_len);
+  size_t actual_len = base64_decode(encoded_string, ret.data(), max_len);
+  ret.resize(actual_len);
+  return ret;
+}
+
+// --- Hex/binary formatting helpers ---
+
+std::string format_mac_address_pretty(const uint8_t *mac) {
+  char buf[18];
+  format_mac_addr_upper(mac, buf);
+  return std::string(buf);
+}
+
+std::string format_hex(const uint8_t *data, size_t length) {
+  std::string ret;
+  ret.resize(length * 2);
+  format_hex_to(&ret[0], length * 2 + 1, data, length);
+  return ret;
+}
+
+std::string format_hex(const std::vector<uint8_t> &data) { return format_hex(data.data(), data.size()); }
+
+// Shared implementation for uint8_t and string hex pretty formatting
+static std::string format_hex_pretty_uint8(const uint8_t *data, size_t length, char separator, bool show_length) {
+  if (data == nullptr || length == 0)
+    return "";
+  std::string ret;
+  size_t hex_len = separator ? (length * 3 - 1) : (length * 2);
+  ret.resize(hex_len);
+  format_hex_pretty_to(&ret[0], hex_len + 1, data, length, separator);
+  if (show_length && length > 4)
+    return ret + " (" + std::to_string(length) + ")";
+  return ret;
+}
+
+std::string format_hex_pretty(const uint8_t *data, size_t length, char separator, bool show_length) {
+  return format_hex_pretty_uint8(data, length, separator, show_length);
+}
+std::string format_hex_pretty(const std::vector<uint8_t> &data, char separator, bool show_length) {
+  return format_hex_pretty(data.data(), data.size(), separator, show_length);
+}
+
+std::string format_hex_pretty(const uint16_t *data, size_t length, char separator, bool show_length) {
+  if (data == nullptr || length == 0)
+    return "";
+  std::string ret;
+  size_t hex_len = separator ? (length * 5 - 1) : (length * 4);
+  ret.resize(hex_len);
+  format_hex_pretty_to(&ret[0], hex_len + 1, data, length, separator);
+  if (show_length && length > 4)
+    return ret + " (" + std::to_string(length) + ")";
+  return ret;
+}
+std::string format_hex_pretty(const std::vector<uint16_t> &data, char separator, bool show_length) {
+  return format_hex_pretty(data.data(), data.size(), separator, show_length);
+}
+std::string format_hex_pretty(const std::string &data, char separator, bool show_length) {
+  return format_hex_pretty_uint8(reinterpret_cast<const uint8_t *>(data.data()), data.length(), separator, show_length);
+}
+
+std::string format_bin(const uint8_t *data, size_t length) {
+  std::string result;
+  result.resize(length * 8);
+  format_bin_to(&result[0], length * 8 + 1, data, length);
+  return result;
+}
+
+// --- MAC address helpers ---
+
+std::string get_mac_address() {
+  uint8_t mac[6];
+  get_mac_address_raw(mac);
+  char buf[13];
+  format_mac_addr_lower_no_sep(mac, buf);
+  return std::string(buf);
+}
+
+std::string get_mac_address_pretty() {
+  char buf[MAC_ADDRESS_PRETTY_BUFFER_SIZE];
+  return std::string(get_mac_address_pretty_into_buffer(buf));
+}
+
+}  // namespace esphome
@@ -0,0 +1,128 @@
+#pragma once
+
+/// @file alloc_helpers.h
+/// @brief Heap-allocating helper functions.
+///
+/// These functions return std::string and allocate heap memory on every call.
+/// On long-running embedded devices, repeated heap allocations fragment memory
+/// over time, eventually causing crashes even with free memory available.
+///
+/// Prefer the stack-based alternatives documented on each function instead.
+/// New code should avoid using these functions.
+
+#include <cstdarg>
+#include <cstdint>
+#include <cstdio>
+#include <string>
+#include <vector>
+
+namespace esphome {
+
+// --- String helpers (allocating) ---
+
+/// Truncate a string to a specific length.
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_truncate(const std::string &str, size_t length);
+
+/// Extract the part of the string until either the first occurrence of the specified character, or the end
+/// (requires str to be null-terminated).
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_until(const char *str, char ch);
+/// Extract the part of the string until either the first occurrence of the specified character, or the end.
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_until(const std::string &str, char ch);
+
+/// Convert the string to lower case.
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_lower_case(const std::string &str);
+
+/// Convert the string to upper case.
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_upper_case(const std::string &str);
+
+/// Convert the string to snake case (lowercase with underscores).
+/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
+std::string str_snake_case(const std::string &str);
+
+/// Sanitizes the input string by removing all characters but alphanumerics, dashes and underscores.
+/// @warning Allocates heap memory. Use str_sanitize_to() with a stack buffer instead.
+std::string str_sanitize(const std::string &str);
+
+/// snprintf-like function returning std::string of maximum length \p len (excluding null terminator).
+/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
+std::string __attribute__((format(printf, 1, 3))) str_snprintf(const char *fmt, size_t len, ...);
+
+/// sprintf-like function returning std::string.
+/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
+std::string __attribute__((format(printf, 1, 2))) str_sprintf(const char *fmt, ...);
+
+// --- Hex/binary formatting helpers (allocating) ---
+
+/// Format the six-byte array \p mac into a MAC address string.
+/// @warning Allocates heap memory. Use format_mac_addr_upper() with a stack buffer instead.
+std::string format_mac_address_pretty(const uint8_t mac[6]);
+
+/// Format the byte array \p data of length \p len in lowercased hex.
+/// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
+std::string format_hex(const uint8_t *data, size_t length);
+
+/// Format the vector \p data in lowercased hex.
+/// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
+std::string format_hex(const std::vector<uint8_t> &data);
+
+/// Format a byte array in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
+std::string format_hex_pretty(const uint8_t *data, size_t length, char separator = '.', bool show_length = true);
+
+/// Format a 16-bit word array in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
+std::string format_hex_pretty(const uint16_t *data, size_t length, char separator = '.', bool show_length = true);
+
+/// Format a byte vector in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
+std::string format_hex_pretty(const std::vector<uint8_t> &data, char separator = '.', bool show_length = true);
+
+/// Format a 16-bit word vector in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
+std::string format_hex_pretty(const std::vector<uint16_t> &data, char separator = '.', bool show_length = true);
+
+/// Format a string's bytes in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
+std::string format_hex_pretty(const std::string &data, char separator = '.', bool show_length = true);
+
+/// Format the byte array \p data of length \p len in binary.
+/// @warning Allocates heap memory. Use format_bin_to() with a stack buffer instead.
+std::string format_bin(const uint8_t *data, size_t length);
+
+// --- Value formatting helpers (allocating) ---
+
+/// Format a float value with accuracy decimals to a string.
+/// @deprecated Allocates heap memory. Use value_accuracy_to_buf() instead. Removed in 2026.7.0.
+__attribute__((deprecated("Allocates heap memory. Use value_accuracy_to_buf() instead. Removed in 2026.7.0.")))
+std::string
+value_accuracy_to_string(float value, int8_t accuracy_decimals);
+
+// --- Base64 helpers (allocating) ---
+
+/// Encode a byte buffer to base64 string.
+/// @warning Allocates heap memory.
+std::string base64_encode(const uint8_t *buf, size_t buf_len);
+/// Encode a byte vector to base64 string.
+/// @warning Allocates heap memory.
+std::string base64_encode(const std::vector<uint8_t> &buf);
+
+/// Decode a base64 string to a byte vector.
+/// @warning Allocates heap memory. Use base64_decode(data, len, buf, buf_len) with a pre-allocated buffer instead.
+std::vector<uint8_t> base64_decode(const std::string &encoded_string);
+
+// --- MAC address helpers (allocating) ---
+
+/// Get the device MAC address as a string, in lowercase hex notation.
+/// @warning Allocates heap memory. Use get_mac_address_into_buffer() instead.
+std::string get_mac_address();
+
+/// Get the device MAC address as a string, in colon-separated uppercase hex notation.
+/// @warning Allocates heap memory. Use get_mac_address_pretty_into_buffer() instead.
+std::string get_mac_address_pretty();
+
+}  // namespace esphome
@@ -214,7 +214,7 @@ void Application::process_dump_config_() {

 void Application::feed_wdt() {
  // Cold entry: callers without a millis() timestamp in hand. Fetches the
-  // time and takes the same rate-limit path as feed_wdt_with_time().
+  // time and takes the same rate-limit paths as feed_wdt_with_time().
  uint32_t now = MillisInternal::get();
  if (now - this->last_wdt_feed_ > WDT_FEED_INTERVAL_MS) {
    this->feed_wdt_slow_(now);
@@ -262,7 +262,7 @@ class Application {
  /// When USE_STATUS_LED is compiled in, also gates a separate (shorter)
  /// interval for dispatching status_led so the LED blink pattern stays
  /// readable even though arch_feed_wdt pokes are now rate-limited at
-  /// 300 ms. The two rate limits are independent so raising
+  /// WDT_FEED_INTERVAL_MS. The two rate limits are independent so raising
  /// WDT_FEED_INTERVAL_MS does not distort the LED cadence.
  void ESPHOME_ALWAYS_INLINE feed_wdt_with_time(uint32_t time) {
    if (static_cast<uint32_t>(time - this->last_wdt_feed_) > WDT_FEED_INTERVAL_MS) [[unlikely]] {
@@ -221,31 +221,7 @@ bool str_endswith_ignore_case(const char *str, size_t str_len, const char *suffi
  return strncasecmp(str + str_len - suffix_len, suffix, suffix_len) == 0;
 }

-std::string str_truncate(const std::string &str, size_t length) {
-  return str.length() > length ? str.substr(0, length) : str;
-}
-std::string str_until(const char *str, char ch) {
-  const char *pos = strchr(str, ch);
-  return pos == nullptr ? std::string(str) : std::string(str, pos - str);
-}
-std::string str_until(const std::string &str, char ch) { return str.substr(0, str.find(ch)); }
-// wrapper around std::transform to run safely on functions from the ctype.h header
-// see https://en.cppreference.com/w/cpp/string/byte/toupper#Notes
-template<int (*fn)(int)> std::string str_ctype_transform(const std::string &str) {
-  std::string result;
-  result.resize(str.length());
-  std::transform(str.begin(), str.end(), result.begin(), [](unsigned char ch) { return fn(ch); });
-  return result;
-}
-std::string str_lower_case(const std::string &str) { return str_ctype_transform<std::tolower>(str); }
-std::string str_upper_case(const std::string &str) { return str_ctype_transform<std::toupper>(str); }
-std::string str_snake_case(const std::string &str) {
-  std::string result = str;
-  for (char &c : result) {
-    c = to_snake_case_char(c);
-  }
-  return result;
-}
+// str_truncate, str_until, str_lower_case, str_upper_case, str_snake_case moved to alloc_helpers.cpp
 char *str_sanitize_to(char *buffer, size_t buffer_size, const char *str) {
  if (buffer_size == 0) {
    return buffer;
@@ -258,41 +234,7 @@ char *str_sanitize_to(char *buffer, size_t buffer_size, const char *str) {
  return buffer;
 }

-std::string str_sanitize(const std::string &str) {
-  std::string result;
-  result.resize(str.size());
-  str_sanitize_to(&result[0], str.size() + 1, str.c_str());
-  return result;
-}
-std::string str_snprintf(const char *fmt, size_t len, ...) {
-  std::string str;
-  va_list args;
-
-  str.resize(len);
-  va_start(args, len);
-  size_t out_length = vsnprintf(&str[0], len + 1, fmt, args);
-  va_end(args);
-
-  if (out_length < len)
-    str.resize(out_length);
-
-  return str;
-}
-std::string str_sprintf(const char *fmt, ...) {
-  std::string str;
-  va_list args;
-
-  va_start(args, fmt);
-  size_t length = vsnprintf(nullptr, 0, fmt, args);
-  va_end(args);
-
-  str.resize(length);
-  va_start(args, fmt);
-  vsnprintf(&str[0], length + 1, fmt, args);
-  va_end(args);
-
-  return str;
-}
+// str_sanitize, str_snprintf, str_sprintf moved to alloc_helpers.cpp

 // Maximum size for name with suffix: 120 (max friendly name) + 1 (separator) + 6 (MAC suffix) + 1 (null term)
 static constexpr size_t MAX_NAME_WITH_SUFFIX_SIZE = 128;
@@ -341,11 +283,7 @@ size_t parse_hex(const char *str, size_t length, uint8_t *data, size_t count) {
  return chars;
 }

-std::string format_mac_address_pretty(const uint8_t *mac) {
-  char buf[18];
-  format_mac_addr_upper(mac, buf);
-  return std::string(buf);
-}
+// format_mac_address_pretty moved to alloc_helpers.cpp

 // Internal helper for hex formatting - base is 'a' for lowercase or 'A' for uppercase.
 // When separator is set, it is written unconditionally after each byte and the last
@@ -398,13 +336,7 @@ char *format_hex_to(char *buffer, size_t buffer_size, const uint8_t *data, size_
  return format_hex_internal(buffer, buffer_size, data, length, 0, 'a');
 }

-std::string format_hex(const uint8_t *data, size_t length) {
-  std::string ret;
-  ret.resize(length * 2);
-  format_hex_to(&ret[0], length * 2 + 1, data, length);
-  return ret;
-}
-std::string format_hex(const std::vector<uint8_t> &data) { return format_hex(data.data(), data.size()); }
+// format_hex (std::string returning overloads) moved to alloc_helpers.cpp

 char *format_hex_pretty_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length, char separator) {
  return format_hex_internal(buffer, buffer_size, data, length, separator, 'A');
@@ -441,43 +373,7 @@ char *format_hex_pretty_to(char *buffer, size_t buffer_size, const uint16_t *dat
  return buffer;
 }

-// Shared implementation for uint8_t and string hex formatting
-static std::string format_hex_pretty_uint8(const uint8_t *data, size_t length, char separator, bool show_length) {
-  if (data == nullptr || length == 0)
-    return "";
-  std::string ret;
-  size_t hex_len = separator ? (length * 3 - 1) : (length * 2);
-  ret.resize(hex_len);
-  format_hex_pretty_to(&ret[0], hex_len + 1, data, length, separator);
-  if (show_length && length > 4)
-    return ret + " (" + std::to_string(length) + ")";
-  return ret;
-}
-
-std::string format_hex_pretty(const uint8_t *data, size_t length, char separator, bool show_length) {
-  return format_hex_pretty_uint8(data, length, separator, show_length);
-}
-std::string format_hex_pretty(const std::vector<uint8_t> &data, char separator, bool show_length) {
-  return format_hex_pretty(data.data(), data.size(), separator, show_length);
-}
-
-std::string format_hex_pretty(const uint16_t *data, size_t length, char separator, bool show_length) {
-  if (data == nullptr || length == 0)
-    return "";
-  std::string ret;
-  size_t hex_len = separator ? (length * 5 - 1) : (length * 4);
-  ret.resize(hex_len);
-  format_hex_pretty_to(&ret[0], hex_len + 1, data, length, separator);
-  if (show_length && length > 4)
-    return ret + " (" + std::to_string(length) + ")";
-  return ret;
-}
-std::string format_hex_pretty(const std::vector<uint16_t> &data, char separator, bool show_length) {
-  return format_hex_pretty(data.data(), data.size(), separator, show_length);
-}
-std::string format_hex_pretty(const std::string &data, char separator, bool show_length) {
-  return format_hex_pretty_uint8(reinterpret_cast<const uint8_t *>(data.data()), data.length(), separator, show_length);
-}
+// format_hex_pretty (all std::string returning overloads) moved to alloc_helpers.cpp

 char *format_bin_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length) {
  if (buffer_size == 0) {
@@ -500,12 +396,7 @@ char *format_bin_to(char *buffer, size_t buffer_size, const uint8_t *data, size_
  return buffer;
 }

-std::string format_bin(const uint8_t *data, size_t length) {
-  std::string result;
-  result.resize(length * 8);
-  format_bin_to(&result[0], length * 8 + 1, data, length);
-  return result;
-}
+// format_bin moved to alloc_helpers.cpp

 ParseOnOffState parse_on_off(const char *str, const char *on, const char *off) {
  if (on == nullptr && ESPHOME_strcasecmp_P(str, ESPHOME_PSTR("on")) == 0)
@@ -537,11 +428,7 @@ static inline void normalize_accuracy_decimals(float &value, int8_t &accuracy_de
  }
 }

-std::string value_accuracy_to_string(float value, int8_t accuracy_decimals) {
-  char buf[VALUE_ACCURACY_MAX_LEN];
-  value_accuracy_to_buf(buf, value, accuracy_decimals);
-  return std::string(buf);
-}
+// value_accuracy_to_string moved to alloc_helpers.cpp

 // Fast float-to-string for accuracy_decimals 0-3 (covers virtually all sensor usage).
 // Avoids snprintf("%.*f") which pulls in heavy float formatting machinery.
@@ -636,45 +523,7 @@ static inline uint8_t base64_find_char(char c) {
 // Check if character is valid base64 or base64url
 static inline bool is_base64(char c) { return (isalnum(c) || (c == '+') || (c == '/') || (c == '-') || (c == '_')); }

-std::string base64_encode(const std::vector<uint8_t> &buf) { return base64_encode(buf.data(), buf.size()); }
-
-// Encode 3 input bytes to 4 base64 characters, append 'count' to ret.
-static inline void base64_encode_triple(const char *char_array_3, int count, std::string &ret) {
-  char char_array_4[4];
-  char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
-  char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
-  char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
-  char_array_4[3] = char_array_3[2] & 0x3f;
-
-  for (int j = 0; j < count; j++)
-    ret += BASE64_CHARS[static_cast<uint8_t>(char_array_4[j])];
-}
-
-std::string base64_encode(const uint8_t *buf, size_t buf_len) {
-  std::string ret;
-  int i = 0;
-  char char_array_3[3];
-
-  while (buf_len--) {
-    char_array_3[i++] = *(buf++);
-    if (i == 3) {
-      base64_encode_triple(char_array_3, 4, ret);
-      i = 0;
-    }
-  }
-
-  if (i) {
-    for (int j = i; j < 3; j++)
-      char_array_3[j] = '\0';
-
-    base64_encode_triple(char_array_3, i + 1, ret);
-
-    while ((i++ < 3))
-      ret += '=';
-  }
-
-  return ret;
-}
+// base64_encode (both overloads) moved to alloc_helpers.cpp

 size_t base64_decode(const std::string &encoded_string, uint8_t *buf, size_t buf_len) {
  return base64_decode(reinterpret_cast<const uint8_t *>(encoded_string.data()), encoded_string.size(), buf, buf_len);
@@ -735,14 +584,7 @@ size_t base64_decode(const uint8_t *encoded_data, size_t encoded_len, uint8_t *b
  return out;
 }

-std::vector<uint8_t> base64_decode(const std::string &encoded_string) {
-  // Calculate maximum decoded size: every 4 base64 chars = 3 bytes
-  size_t max_len = ((encoded_string.size() + 3) / 4) * 3;
-  std::vector<uint8_t> ret(max_len);
-  size_t actual_len = base64_decode(encoded_string, ret.data(), max_len);
-  ret.resize(actual_len);
-  return ret;
-}
+// base64_decode (vector-returning overload) moved to alloc_helpers.cpp

 /// Decode base64/base64url string directly into vector of little-endian int32 values
 /// @param base64 Base64 or base64url encoded string (both +/ and -_ accepted)
@@ -881,18 +723,7 @@ void HighFrequencyLoopRequester::stop() {
  this->started_ = false;
 }

-std::string get_mac_address() {
-  uint8_t mac[6];
-  get_mac_address_raw(mac);
-  char buf[13];
-  format_mac_addr_lower_no_sep(mac, buf);
-  return std::string(buf);
-}
-
-std::string get_mac_address_pretty() {
-  char buf[MAC_ADDRESS_PRETTY_BUFFER_SIZE];
-  return std::string(get_mac_address_pretty_into_buffer(buf));
-}
+// get_mac_address, get_mac_address_pretty moved to alloc_helpers.cpp

 void get_mac_address_into_buffer(std::span<char, MAC_ADDRESS_BUFFER_SIZE> buf) {
  uint8_t mac[6];
@@ -21,6 +21,12 @@

 #include "esphome/core/optional.h"

+// Backward compatibility re-export of heap-allocating helpers.
+// These functions have moved to alloc_helpers.h. External components should
+// update their includes to use #include "esphome/core/alloc_helpers.h" directly.
+// This re-export will be removed in 2026.11.0.
+#include "esphome/core/alloc_helpers.h"
+
 #ifdef USE_ESP8266
 #include <Esp.h>
 #include <pgmspace.h>
@@ -979,27 +985,13 @@ inline bool str_endswith_ignore_case(const std::string &str, const char *suffix)
  return str_endswith_ignore_case(str.c_str(), str.size(), suffix, strlen(suffix));
 }

-/// Truncate a string to a specific length.
-/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
-std::string str_truncate(const std::string &str, size_t length);
+// str_truncate moved to alloc_helpers.h - remove this include before 2026.11.0

-/// Extract the part of the string until either the first occurrence of the specified character, or the end
-/// (requires str to be null-terminated).
-std::string str_until(const char *str, char ch);
-/// Extract the part of the string until either the first occurrence of the specified character, or the end.
-std::string str_until(const std::string &str, char ch);
-
-/// Convert the string to lower case.
-std::string str_lower_case(const std::string &str);
-/// Convert the string to upper case.
-/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
-std::string str_upper_case(const std::string &str);
+// str_until, str_lower_case, str_upper_case moved to alloc_helpers.h - remove this comment before 2026.11.0

 /// Convert a single char to snake_case: lowercase and space to underscore.
 constexpr char to_snake_case_char(char c) { return (c == ' ') ? '_' : (c >= 'A' && c <= 'Z') ? c + ('a' - 'A') : c; }
-/// Convert the string to snake case (lowercase with underscores).
-/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
-std::string str_snake_case(const std::string &str);
+// str_snake_case moved to alloc_helpers.h - remove this comment before 2026.11.0

 /// Sanitize a single char: keep alphanumerics, dashes, underscores; replace others with underscore.
 constexpr char to_sanitized_char(char c) {
@@ -1022,9 +1014,7 @@ template<size_t N> inline char *str_sanitize_to(char (&buffer)[N], const char *s
  return str_sanitize_to(buffer, N, str);
 }

-/// Sanitizes the input string by removing all characters but alphanumerics, dashes and underscores.
-/// @warning Allocates heap memory. Use str_sanitize_to() with a stack buffer instead.
-std::string str_sanitize(const std::string &str);
+// str_sanitize moved to alloc_helpers.h - remove this comment before 2026.11.0

 /// Calculate FNV-1 hash of a string while applying snake_case + sanitize transformations.
 /// This computes object_id hashes directly from names without creating an intermediate buffer.
@@ -1040,13 +1030,7 @@ inline uint32_t fnv1_hash_object_id(const char *str, size_t len) {
  return hash;
 }

-/// snprintf-like function returning std::string of maximum length \p len (excluding null terminator).
-/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
-std::string __attribute__((format(printf, 1, 3))) str_snprintf(const char *fmt, size_t len, ...);
-
-/// sprintf-like function returning std::string.
-/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
-std::string __attribute__((format(printf, 1, 2))) str_sprintf(const char *fmt, ...);
+// str_snprintf, str_sprintf moved to alloc_helpers.h - remove this comment before 2026.11.0

 #ifdef USE_ESP8266
 // ESP8266: Use vsnprintf_P to keep format strings in flash (PROGMEM)
@@ -1095,7 +1079,33 @@ __attribute__((format(printf, 4, 5))) inline size_t buf_append_printf(char *buf,
 }
 #endif

-/// Safely append a string to buffer without format parsing, returning new position (capped at size).
+#ifdef USE_ESP8266
+/// Safely append a PROGMEM string to buffer, returning new position (capped at size).
+/// ESP8266 internal implementation — prefer the `buf_append_str` macro which wraps
+/// literals with `PSTR()` automatically so they stay in flash instead of eating RAM.
+/// @param buf Output buffer
+/// @param size Total buffer size
+/// @param pos Current position in buffer
+/// @param str PROGMEM-resident string to append (must not be null)
+/// @return New position after appending; returns `size` if `pos >= size`, otherwise
+///         returns at most `size - 1` because one byte is reserved for the null terminator
+inline size_t buf_append_str_p(char *buf, size_t size, size_t pos, PGM_P str) {
+  if (pos >= size) {
+    return size;
+  }
+  size_t remaining = size - pos - 1;  // reserve space for null terminator
+  size_t len = strnlen_P(str, remaining);
+  memcpy_P(buf + pos, str, len);
+  pos += len;
+  buf[pos] = '\0';
+  return pos;
+}
+/// Safely append a string to buffer, returning new position (capped at size).
+/// More efficient than buf_append_printf for plain string literals.
+/// On ESP8266 the literal is wrapped with PSTR() so it stays in flash.
+#define buf_append_str(buf, size, pos, str) buf_append_str_p(buf, size, pos, PSTR(str))
+#else
+/// Safely append a string to buffer, returning new position (capped at size).
 /// More efficient than buf_append_printf for plain string literals.
 /// @param buf Output buffer
 /// @param size Total buffer size
@@ -1107,15 +1117,13 @@ inline size_t buf_append_str(char *buf, size_t size, size_t pos, const char *str
    return size;
  }
  size_t remaining = size - pos - 1;  // reserve space for null terminator
-  size_t len = strlen(str);
-  if (len > remaining) {
-    len = remaining;
-  }
+  size_t len = strnlen(str, remaining);
  memcpy(buf + pos, str, len);
  pos += len;
  buf[pos] = '\0';
  return pos;
 }
+#endif

 /// Concatenate a name with a separator and suffix using an efficient stack-based approach.
 /// This avoids multiple heap allocations during string construction.
@@ -1476,189 +1484,26 @@ inline void format_mac_addr_lower_no_sep(const uint8_t *mac, char *output) {
  format_hex_to(output, MAC_ADDRESS_BUFFER_SIZE, mac, MAC_ADDRESS_SIZE);
 }

-/// Format the six-byte array \p mac into a MAC address.
-/// @warning Allocates heap memory. Use format_mac_addr_upper() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
-std::string format_mac_address_pretty(const uint8_t mac[6]);
-/// Format the byte array \p data of length \p len in lowercased hex.
-/// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
-std::string format_hex(const uint8_t *data, size_t length);
-/// Format the vector \p data in lowercased hex.
-/// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
-std::string format_hex(const std::vector<uint8_t> &data);
+// format_mac_address_pretty, format_hex (all overloads) moved to alloc_helpers.h
+// Remove this comment and the template overloads below before 2026.11.0
+
 /// Format an unsigned integer in lowercased hex, starting with the most significant byte.
 /// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
 template<typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0> std::string format_hex(T val) {
  val = convert_big_endian(val);
  return format_hex(reinterpret_cast<uint8_t *>(&val), sizeof(T));
 }
 /// Format the std::array \p data in lowercased hex.
 /// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
 template<std::size_t N> std::string format_hex(const std::array<uint8_t, N> &data) {
  return format_hex(data.data(), data.size());
 }

-/** Format a byte array in pretty-printed, human-readable hex format.
- *
- * Converts binary data to a hexadecimal string representation with customizable formatting.
- * Each byte is displayed as a two-digit uppercase hex value, separated by the specified separator.
- * Optionally includes the total byte count in parentheses at the end.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @param data Pointer to the byte array to format.
- * @param length Number of bytes in the array.
- * @param separator Character to use between hex bytes (default: '.').
- * @param show_length Whether to append the byte count in parentheses (default: true).
- * @return Formatted hex string, e.g., "A1.B2.C3.D4.E5 (5)" or "A1:B2:C3" depending on parameters.
- *
- * @note Returns empty string if data is nullptr or length is 0.
- * @note The length will only be appended if show_length is true AND the length is greater than 4.
- *
- * Example:
- * @code
- * uint8_t data[] = {0xA1, 0xB2, 0xC3};
- * format_hex_pretty(data, 3);           // Returns "A1.B2.C3" (no length shown for <= 4 parts)
- * uint8_t data2[] = {0xA1, 0xB2, 0xC3, 0xD4, 0xE5};
- * format_hex_pretty(data2, 5);          // Returns "A1.B2.C3.D4.E5 (5)"
- * format_hex_pretty(data2, 5, ':');     // Returns "A1:B2:C3:D4:E5 (5)"
- * format_hex_pretty(data2, 5, '.', false); // Returns "A1.B2.C3.D4.E5"
- * @endcode
- */
-std::string format_hex_pretty(const uint8_t *data, size_t length, char separator = '.', bool show_length = true);
+// format_hex_pretty (all overloads) moved to alloc_helpers.h
+// Remove this comment and the template overload below before 2026.11.0

-/** Format a 16-bit word array in pretty-printed, human-readable hex format.
- *
- * Similar to the byte array version, but formats 16-bit words as 4-digit hex values.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @param data Pointer to the 16-bit word array to format.
- * @param length Number of 16-bit words in the array.
- * @param separator Character to use between hex words (default: '.').
- * @param show_length Whether to append the word count in parentheses (default: true).
- * @return Formatted hex string with 4-digit hex values per word.
- *
- * @note The length will only be appended if show_length is true AND the length is greater than 4.
- *
- * Example:
- * @code
- * uint16_t data[] = {0xA1B2, 0xC3D4};
- * format_hex_pretty(data, 2); // Returns "A1B2.C3D4" (no length shown for <= 4 parts)
- * uint16_t data2[] = {0xA1B2, 0xC3D4, 0xE5F6};
- * format_hex_pretty(data2, 3); // Returns "A1B2.C3D4.E5F6 (3)"
- * @endcode
- */
-std::string format_hex_pretty(const uint16_t *data, size_t length, char separator = '.', bool show_length = true);
-
-/** Format a byte vector in pretty-printed, human-readable hex format.
- *
- * Convenience overload for std::vector<uint8_t>. Formats each byte as a two-digit
- * uppercase hex value with customizable separator.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @param data Vector of bytes to format.
- * @param separator Character to use between hex bytes (default: '.').
- * @param show_length Whether to append the byte count in parentheses (default: true).
- * @return Formatted hex string representation of the vector contents.
- *
- * @note The length will only be appended if show_length is true AND the vector size is greater than 4.
- *
- * Example:
- * @code
- * std::vector<uint8_t> data = {0xDE, 0xAD, 0xBE, 0xEF};
- * format_hex_pretty(data);        // Returns "DE.AD.BE.EF" (no length shown for <= 4 parts)
- * std::vector<uint8_t> data2 = {0xDE, 0xAD, 0xBE, 0xEF, 0xCA};
- * format_hex_pretty(data2);       // Returns "DE.AD.BE.EF.CA (5)"
- * format_hex_pretty(data2, '-');  // Returns "DE-AD-BE-EF-CA (5)"
- * @endcode
- */
-std::string format_hex_pretty(const std::vector<uint8_t> &data, char separator = '.', bool show_length = true);
-
-/** Format a 16-bit word vector in pretty-printed, human-readable hex format.
- *
- * Convenience overload for std::vector<uint16_t>. Each 16-bit word is formatted
- * as a 4-digit uppercase hex value in big-endian order.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @param data Vector of 16-bit words to format.
- * @param separator Character to use between hex words (default: '.').
- * @param show_length Whether to append the word count in parentheses (default: true).
- * @return Formatted hex string representation of the vector contents.
- *
- * @note The length will only be appended if show_length is true AND the vector size is greater than 4.
- *
- * Example:
- * @code
- * std::vector<uint16_t> data = {0x1234, 0x5678};
- * format_hex_pretty(data); // Returns "1234.5678" (no length shown for <= 4 parts)
- * std::vector<uint16_t> data2 = {0x1234, 0x5678, 0x9ABC};
- * format_hex_pretty(data2); // Returns "1234.5678.9ABC (3)"
- * @endcode
- */
-std::string format_hex_pretty(const std::vector<uint16_t> &data, char separator = '.', bool show_length = true);
-
-/** Format a string's bytes in pretty-printed, human-readable hex format.
- *
- * Treats each character in the string as a byte and formats it in hex.
- * Useful for debugging binary data stored in std::string containers.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @param data String whose bytes should be formatted as hex.
- * @param separator Character to use between hex bytes (default: '.').
- * @param show_length Whether to append the byte count in parentheses (default: true).
- * @return Formatted hex string representation of the string's byte contents.
- *
- * @note The length will only be appended if show_length is true AND the string length is greater than 4.
- *
- * Example:
- * @code
- * std::string data = "ABC";  // ASCII: 0x41, 0x42, 0x43
- * format_hex_pretty(data);   // Returns "41.42.43" (no length shown for <= 4 parts)
- * std::string data2 = "ABCDE";
- * format_hex_pretty(data2);  // Returns "41.42.43.44.45 (5)"
- * @endcode
- */
-std::string format_hex_pretty(const std::string &data, char separator = '.', bool show_length = true);
-
-/** Format an unsigned integer in pretty-printed, human-readable hex format.
- *
- * Converts the integer to big-endian byte order and formats each byte as hex.
- * The most significant byte appears first in the output string.
- *
- * @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
- * Causes heap fragmentation on long-running devices.
- *
- * @tparam T Unsigned integer type (uint8_t, uint16_t, uint32_t, uint64_t, etc.).
- * @param val The unsigned integer value to format.
- * @param separator Character to use between hex bytes (default: '.').
- * @param show_length Whether to append the byte count in parentheses (default: true).
- * @return Formatted hex string with most significant byte first.
- *
- * @note The length will only be appended if show_length is true AND sizeof(T) is greater than 4.
- *
- * Example:
- * @code
- * uint32_t value = 0x12345678;
- * format_hex_pretty(value);        // Returns "12.34.56.78" (no length shown for <= 4 parts)
- * uint64_t value2 = 0x123456789ABCDEF0;
- * format_hex_pretty(value2);       // Returns "12.34.56.78.9A.BC.DE.F0 (8)"
- * format_hex_pretty(value2, ':');  // Returns "12:34:56:78:9A:BC:DE:F0 (8)"
- * format_hex_pretty<uint16_t>(0x1234); // Returns "12.34"
- * @endcode
- */
+/// Format an unsigned integer in pretty-printed, human-readable hex format.
+/// @warning Allocates heap memory. Use format_hex_pretty_to() with a stack buffer instead.
 template<typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0>
 std::string format_hex_pretty(T val, char separator = '.', bool show_length = true) {
  val = convert_big_endian(val);
@@ -1718,13 +1563,10 @@ inline char *format_bin_to(char (&buffer)[N], T val) {
  return format_bin_to(buffer, reinterpret_cast<const uint8_t *>(&val), sizeof(T));
 }

-/// Format the byte array \p data of length \p len in binary.
-/// @warning Allocates heap memory. Use format_bin_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
-std::string format_bin(const uint8_t *data, size_t length);
+// format_bin moved to alloc_helpers.h - remove this comment and template overload before 2026.11.0
+
 /// Format an unsigned integer in binary, starting with the most significant byte.
 /// @warning Allocates heap memory. Use format_bin_to() with a stack buffer instead.
-/// Causes heap fragmentation on long-running devices.
 template<typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0> std::string format_bin(T val) {
  val = convert_big_endian(val);
  return format_bin(reinterpret_cast<uint8_t *>(&val), sizeof(T));
@@ -1740,9 +1582,7 @@ enum ParseOnOffState : uint8_t {
 /// Parse a string that contains either on, off or toggle.
 ParseOnOffState parse_on_off(const char *str, const char *on = nullptr, const char *off = nullptr);

-/// @deprecated Allocates heap memory. Use value_accuracy_to_buf() instead. Removed in 2026.7.0.
-ESPDEPRECATED("Allocates heap memory. Use value_accuracy_to_buf() instead. Removed in 2026.7.0.", "2026.1.0")
-std::string value_accuracy_to_string(float value, int8_t accuracy_decimals);
+// value_accuracy_to_string moved to alloc_helpers.h - remove this comment before 2026.11.0

 /// Maximum buffer size for value_accuracy formatting (float ~15 chars + space + UOM ~40 chars + null)
 static constexpr size_t VALUE_ACCURACY_MAX_LEN = 64;
@@ -1756,10 +1596,8 @@ size_t value_accuracy_with_uom_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> bu
 /// Derive accuracy in decimals from an increment step.
 int8_t step_to_accuracy_decimals(float step);

-std::string base64_encode(const uint8_t *buf, size_t buf_len);
-std::string base64_encode(const std::vector<uint8_t> &buf);
-
-std::vector<uint8_t> base64_decode(const std::string &encoded_string);
+// base64_encode (both overloads), base64_decode (vector overload) moved to alloc_helpers.h
+// Remove this comment before 2026.11.0
 size_t base64_decode(std::string const &encoded_string, uint8_t *buf, size_t buf_len);
 size_t base64_decode(const uint8_t *encoded_data, size_t encoded_len, uint8_t *buf, size_t buf_len);

@@ -2195,15 +2033,7 @@ class HighFrequencyLoopRequester {
 /// Get the device MAC address as raw bytes, written into the provided byte array (6 bytes).
 void get_mac_address_raw(uint8_t *mac);  // NOLINT(readability-non-const-parameter)

-/// Get the device MAC address as a string, in lowercase hex notation.
-/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
-/// Use get_mac_address_into_buffer() instead.
-std::string get_mac_address();
-
-/// Get the device MAC address as a string, in colon-separated uppercase hex notation.
-/// @warning Allocates heap memory. Avoid in new code - causes heap fragmentation on long-running devices.
-/// Use get_mac_address_pretty_into_buffer() instead.
-std::string get_mac_address_pretty();
+// get_mac_address, get_mac_address_pretty moved to alloc_helpers.h - remove this comment before 2026.11.0

 /// Get the device MAC address into the given buffer, in lowercase hex notation.
 /// Assumes buffer length is MAC_ADDRESS_BUFFER_SIZE (12 digits for hexadecimal representation followed by null
@@ -631,33 +631,43 @@ def Pvariable(id_: ID, rhs: SafeExpType, type_: "MockObj" = None) -> "MockObj":
    if isinstance(rhs, MockObj) and rhs.is_new_expr:
        # For 'new' allocations, use placement new into static storage
        # to avoid heap fragmentation on embedded devices.
-        the_type = id_.type
+        #
+        # Storage must be sized and aligned for the actual instantiated class,
+        # which may be a subclass of id_.type (e.g. `cv.declare_id(BaseClass)`
+        # combined with `SubClass.new()` — used by ili9xxx, waveshare_epaper,
+        # etc. to select a model-specific constructor). Using id_.type would
+        # run the base-class default constructor instead, silently losing any
+        # subclass initialization. Template args live on the CallExpression
+        # and are re-emitted below.
+        call_expr = rhs.base
+        assert isinstance(call_expr, CallExpression), (
+            f"Expected CallExpression for placement new, got {type(call_expr)}"
+        )
+        actual_type = rhs.new_type if rhs.new_type is not None else id_.type
+        if call_expr.template_args is not None:
+            actual_type = f"{actual_type}{call_expr.template_args}"
+        pointer_type = id_.type
        # Extract component namespace from type for memory analysis attribution
-        component_ns = _extract_component_ns(str(the_type))
+        component_ns = _extract_component_ns(str(actual_type))
        storage_name = f"{component_ns}__{id_.id}__pstorage"

        # Declare aligned byte array for the object storage
        CORE.add_global(
            RawStatement(
-                f"alignas({the_type}) static unsigned char {storage_name}[sizeof({the_type})];"
+                f"alignas({actual_type}) static unsigned char {storage_name}[sizeof({actual_type})];"
            )
        )
+        # Pointer declaration uses id_.type to preserve the declared base-class
+        # pointer type for downstream callers (polymorphism through base ptr).
        CORE.add_global(
            AssignmentExpression(
-                f"static {the_type}",
+                f"static {pointer_type}",
                "*const ",
                id_,
-                MockObj(f"reinterpret_cast<{the_type} *>({storage_name})"),
+                MockObj(f"reinterpret_cast<{pointer_type} *>({storage_name})"),
            )
        )
-        # Extract args from the CallExpression and rebuild as placement new.
-        # Template args are already encoded in the_type (e.g. GlobalsComponent<int>),
-        # so we only pass the constructor args, not template_args.
-        call_expr = rhs.base
-        assert isinstance(call_expr, CallExpression), (
-            f"Expected CallExpression for placement new, got {type(call_expr)}"
-        )
-        placement_new = CallExpression(f"new({id_.id}) {the_type}", *call_expr.args)
+        placement_new = CallExpression(f"new({id_.id}) {actual_type}", *call_expr.args)
        CORE.add(ExpressionStatement(placement_new))
    else:
        decl = VariableDeclarationExpression(id_.type, "*", id_, static=True)
@@ -894,12 +904,16 @@ class MockObj(Expression):
    Mostly consists of magic methods that allow ESPHome's codegen syntax.
    """

-    __slots__ = ("base", "op", "is_new_expr")
+    __slots__ = ("base", "op", "is_new_expr", "new_type")

-    def __init__(self, base, op=".", is_new_expr=False) -> None:
+    def __init__(self, base, op=".", is_new_expr=False, new_type=None) -> None:
        self.base = base
        self.op = op
        self.is_new_expr = is_new_expr
+        # For `is_new_expr=True` objects, `new_type` holds the class name being
+        # constructed (e.g. "ili9xxx::ILI9XXXST7789V"). Needed by Pvariable so
+        # placement new uses the actual subclass rather than id_.type.
+        self.new_type = new_type

    def __getattr__(self, attr: str) -> "MockObj":
        # prevent python dunder methods being replaced by mock objects
@@ -914,7 +928,9 @@ class MockObj(Expression):

    def __call__(self, *args: SafeExpType) -> "MockObj":
        call = CallExpression(self.base, *args)
-        return MockObj(call, self.op, is_new_expr=self.is_new_expr)
+        return MockObj(
+            call, self.op, is_new_expr=self.is_new_expr, new_type=self.new_type
+        )

    def __str__(self):
        return str(self.base)
@@ -928,7 +944,7 @@ class MockObj(Expression):

    @property
    def new(self) -> "MockObj":
-        return MockObj(f"new {self.base}", "->", is_new_expr=True)
+        return MockObj(f"new {self.base}", "->", is_new_expr=True, new_type=self.base)

    def template(self, *args: SafeExpType) -> "MockObj":
        """Apply template parameters to this object."""
@@ -3,6 +3,8 @@ dependencies:
    version: "7.4.2"
  esphome/esp-audio-libs:
    version: 2.0.4
+  esphome/esp-micro-speech-features:
+    version: 1.2.3
  esphome/micro-decoder:
    version: 0.1.1
  esphome/micro-flac:
@@ -162,7 +162,6 @@ lib_deps =
    makuna/NeoPixelBus@2.8.0             ; neopixelbus
    esphome/ESP32-audioI2S@2.3.0         ; i2s_audio
    droscy/esp_wireguard@0.4.5           ; wireguard
-    kahrendt/ESPMicroSpeechFeatures@1.1.0  ; micro_wake_word

 build_flags =
    ${common:arduino.build_flags}
@@ -184,7 +183,6 @@ framework = espidf
 lib_deps =
    ${common:idf.lib_deps}
    droscy/esp_wireguard@0.4.5              ; wireguard
-    kahrendt/ESPMicroSpeechFeatures@1.1.0   ; micro_wake_word
    tonia/HeatpumpIR@1.0.41                 ; heatpumpir
 build_flags =
    ${common:idf.build_flags}
@@ -722,18 +722,22 @@ def lint_trailing_whitespace(fname, match):
 # Heap-allocating helpers that cause fragmentation on long-running embedded devices.
 # These return std::string and should be replaced with stack-based alternatives.
 HEAP_ALLOCATING_HELPERS = {
+    "base64_encode": "base64_encode_to() with a pre-allocated buffer",
    "format_bin": "format_bin_to() with a stack buffer",
    "format_hex": "format_hex_to() with a stack buffer",
    "format_hex_pretty": "format_hex_pretty_to() with a stack buffer",
    "format_mac_address_pretty": "format_mac_addr_upper() with a stack buffer",
    "get_mac_address": "get_mac_address_into_buffer() with a stack buffer",
    "get_mac_address_pretty": "get_mac_address_pretty_into_buffer() with a stack buffer",
+    "str_lower_case": "manual tolower() with a stack buffer",
    "str_sanitize": "str_sanitize_to() with a stack buffer",
    "str_truncate": "removal (function is unused)",
+    "str_until": "manual strchr()/find() with a StringRef or stack buffer",
    "str_upper_case": "removal (function is unused)",
    "str_snake_case": "removal (function is unused)",
    "str_sprintf": "snprintf() with a stack buffer",
    "str_snprintf": "snprintf() with a stack buffer",
+    "value_accuracy_to_string": "value_accuracy_to_buf() with a stack buffer",
 }


@@ -743,24 +747,33 @@ HEAP_ALLOCATING_HELPERS = {
    # get_mac_address(?!_) ensures we don't match get_mac_address_into_buffer, etc.
    # CPP_RE_EOL captures rest of line so NOLINT comments are detected
    r"[^\w]("
+    r"base64_encode(?!_)|"
    r"format_bin(?!_)|"
    r"format_hex(?!_)|"
    r"format_hex_pretty(?!_)|"
    r"format_mac_address_pretty|"
    r"get_mac_address_pretty(?!_)|"
    r"get_mac_address(?!_)|"
+    r"str_lower_case|"
    r"str_sanitize(?!_)|"
    r"str_truncate|"
+    r"str_until|"
    r"str_upper_case|"
    r"str_snake_case|"
    r"str_sprintf|"
-    r"str_snprintf"
+    r"str_snprintf|"
+    r"value_accuracy_to_string"
    r")\s*\(" + CPP_RE_EOL,
    include=cpp_include,
    exclude=[
        # The definitions themselves
+        "esphome/core/alloc_helpers.h",
+        "esphome/core/alloc_helpers.cpp",
+        # Backward compatibility re-exports (remove before 2026.11.0)
        "esphome/core/helpers.h",
        "esphome/core/helpers.cpp",
+        # Vendored third-party library
+        "esphome/components/http_request/httplib.h",
    ],
 )
 def lint_no_heap_allocating_helpers(fname, match):
@@ -812,6 +825,7 @@ def lint_no_sprintf(fname, match):
        "esphome/components/http_request/httplib.h",
        # Deprecated helpers that return std::string
        "esphome/core/helpers.cpp",
+        "esphome/core/alloc_helpers.cpp",
        # The using declaration itself
        "esphome/core/helpers.h",
        # Test fixtures - not production embedded code
@@ -0,0 +1,20 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: arduino
+
+spi:
+  clk_pin: GPIO18
+  mosi_pin: GPIO23
+
+display:
+  - platform: ili9xxx
+    id: tft_display
+    model: ST7789V
+    cs_pin: GPIO5
+    dc_pin: GPIO17
+    reset_pin: GPIO16
+    invert_colors: false
@@ -0,0 +1,31 @@
+"""Tests for the ili9xxx component."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+
+
+def test_ili9xxx_placement_new_uses_model_subclass(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Regression test for ili9xxx picking the right constructor under placement new.
+
+    ili9xxx declares the ID as the base ``ILI9XXXDisplay`` but constructs a
+    model-specific subclass (e.g. ``ILI9XXXST7789V``) via ``MODELS[...].new()``.
+    Pvariable must emit placement new for the subclass — otherwise the base
+    default constructor runs and the panel is left with a null init sequence
+    and 0x0 dimensions, producing a silent blank screen.
+    """
+    main_cpp = generate_main(component_config_path("ili9xxx_test.yaml"))
+
+    # Storage is sized for the subclass so the full object fits.
+    assert "sizeof(ili9xxx::ILI9XXXST7789V)" in main_cpp
+    assert "alignas(ili9xxx::ILI9XXXST7789V)" in main_cpp
+    # Pointer is declared as the base type for polymorphism.
+    assert "static ili9xxx::ILI9XXXDisplay *const tft_display" in main_cpp
+    # Placement new runs the subclass constructor — this is the actual regression fix.
+    assert "new(tft_display) ili9xxx::ILI9XXXST7789V()" in main_cpp
+    # Base-class default constructor must NOT be used.
+    assert "new(tft_display) ili9xxx::ILI9XXXDisplay()" not in main_cpp
@@ -7,6 +7,11 @@ import pytest

 from esphome import config_validation as cv
 from esphome.components.esp32 import KEY_BOARD, VARIANT_ESP32P4
+
+# Importing xl9535 registers its pin schema with pins.PIN_SCHEMA_REGISTRY so that
+# models (e.g. SEEED-RETERMINAL-D1001) that reference xl9535-backed pins in their
+# defaults can be validated by the mipi_dsi CONFIG_SCHEMA in this test.
+import esphome.components.xl9535  # noqa: F401
 from esphome.const import (
    CONF_DIMENSIONS,
    CONF_HEIGHT,
@@ -145,3 +145,19 @@ display:
      it.filled_rectangle(0, 0, it.get_width(), it.get_height(), Color::WHITE);
      it.circle(it.get_width() / 2, it.get_height() / 2, 30, Color::BLACK);
      it.circle(it.get_width() / 2, it.get_height() / 2, 20, Color(255, 0, 0));
+
+  - platform: epaper_spi
+    spi_id: spi_bus
+    model: goodisplay-gdey042t81-4.2
+    cs_pin:
+      allow_other_uses: true
+      number: GPIO5
+    dc_pin:
+      allow_other_uses: true
+      number: GPIO17
+    reset_pin:
+      allow_other_uses: true
+      number: GPIO16
+    busy_pin:
+      allow_other_uses: true
+      number: GPIO4
@@ -0,0 +1,22 @@
+#include <gtest/gtest.h>
+
+#include "esphome/components/modbus/modbus_helpers.h"
+
+namespace esphome::modbus::helpers {
+
+TEST(ModbusHelpersTest, PayloadToNumberRejectsOffsetAtEndOfBuffer) {
+  const std::vector<uint8_t> data{0x12, 0x34};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_WORD, 2, 0xFFFFFFFF), 0);
+}
+
+TEST(ModbusHelpersTest, PayloadToNumberRejectsTruncatedMultiRegisterValue) {
+  const std::vector<uint8_t> data{0x12, 0x34, 0x56};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_DWORD, 0, 0xFFFFFFFF), 0);
+}
+
+TEST(ModbusHelpersTest, PayloadToNumberDecodesValidWord) {
+  const std::vector<uint8_t> data{0x12, 0x34};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_WORD, 0, 0xFFFFFFFF), 0x1234);
+}
+
+}  // namespace esphome::modbus::helpers
@@ -3,6 +3,22 @@ esphome:
    then:
      - rtttl.play: 'siren:d=8,o=5,b=100:d,e,d,e,d,e,d,e'
      - rtttl.stop
+      # Test all note features: all notes, denominators (1,2,4,8,16,32), sharp (#), octaves (4-7), dotted (.), note gap (c5,c5), pause (p)
+      - rtttl.play: 'special:d=4,o=5,b=120:1c4,2d#5,4e6.,8f#7,16g4,32a5,8a#5,4b6,8h5,c5,c5,8p,2c4'
+      # Different orders of control parameters
+      - rtttl.play: 'test_odb:o=5,d=8,b=100:c'
+      - rtttl.play: 'test_bod:b=100,o=5,d=8:c'
+      - rtttl.play: 'test_bdo:b=100,d=8,o=5:c'
+      - rtttl.play: 'test_obd:o=5,b=100,d=8:c'
+      - rtttl.play: 'test_dbo:d=8,b=100,o=5:c'
+      # Missing parameters (use defaults)
+      - rtttl.play: 'test_no_d:o=5,b=100:c'
+      - rtttl.play: 'test_no_o:d=8,b=100:c'
+      - rtttl.play: 'test_no_b:d=8,o=5:c'
+      - rtttl.play: 'test_only_d:d=8:c'
+      - rtttl.play: 'test_only_o:o=5:c'
+      - rtttl.play: 'test_only_b:b=100:c'
+      - rtttl.play: 'test_empty::c'

 output:
  - platform: ${output_platform}