From 2d4cd4ce7e34dae4632b20cf13e42ec957820b21 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 5 Jan 2026 17:15:50 -1000
Subject: [PATCH] [midea] Reduce heap allocations with stack-based string
 formatting (#13000)

---
 esphome/components/midea_ir/midea_ir.cpp          | 3 ++-
 esphome/components/remote_base/midea_protocol.cpp | 5 ++++-
 esphome/components/remote_base/midea_protocol.h   | 7 +++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/esphome/components/midea_ir/midea_ir.cpp b/esphome/components/midea_ir/midea_ir.cpp
index c269b2f7d9..eaee1c731c 100644
--- a/esphome/components/midea_ir/midea_ir.cpp
+++ b/esphome/components/midea_ir/midea_ir.cpp
@@ -165,7 +165,8 @@ bool MideaIR::on_receive(remote_base::RemoteReceiveData data) {
 }
 
 bool MideaIR::on_midea_(const MideaData &data) {
-  ESP_LOGV(TAG, "Decoded Midea IR data: %s", data.to_string().c_str());
+  char buf[MideaData::TO_STR_BUFFER_SIZE];
+  ESP_LOGV(TAG, "Decoded Midea IR data: %s", data.to_str(buf));
   if (data.type() == MideaData::MIDEA_TYPE_CONTROL) {
     const ControlData status = data;
     if (status.get_mode() != climate::CLIMATE_MODE_FAN_ONLY)
diff --git a/esphome/components/remote_base/midea_protocol.cpp b/esphome/components/remote_base/midea_protocol.cpp
index 8006fe4048..4fa717cf08 100644
--- a/esphome/components/remote_base/midea_protocol.cpp
+++ b/esphome/components/remote_base/midea_protocol.cpp
@@ -70,7 +70,10 @@ optional<MideaData> MideaProtocol::decode(RemoteReceiveData src) {
   return {};
 }
 
-void MideaProtocol::dump(const MideaData &data) { ESP_LOGI(TAG, "Received Midea: %s", data.to_string().c_str()); }
+void MideaProtocol::dump(const MideaData &data) {
+  char buf[MideaData::TO_STR_BUFFER_SIZE];
+  ESP_LOGI(TAG, "Received Midea: %s", data.to_str(buf));
+}
 
 }  // namespace remote_base
 }  // namespace esphome
diff --git a/esphome/components/remote_base/midea_protocol.h b/esphome/components/remote_base/midea_protocol.h
index 94fb6f3d94..0a5de8e9df 100644
--- a/esphome/components/remote_base/midea_protocol.h
+++ b/esphome/components/remote_base/midea_protocol.h
@@ -30,6 +30,13 @@ class MideaData {
   void finalize() { this->data_[OFFSET_CS] = this->calc_cs_(); }
   bool is_compliment(const MideaData &rhs) const;
   std::string to_string() const { return format_hex_pretty(this->data_.data(), this->data_.size()); }
+  /// Buffer size for to_str(): 6 bytes = "AA.BB.CC.DD.EE.FF\0"
+  static constexpr size_t TO_STR_BUFFER_SIZE = format_hex_pretty_size(6);
+  /// Format to buffer, returns pointer to buffer
+  const char *to_str(char *buffer) const {
+    format_hex_pretty_to(buffer, TO_STR_BUFFER_SIZE, this->data_.data(), this->data_.size(), '.');
+    return buffer;
+  }
   // compare only 40-bits
   bool operator==(const MideaData &rhs) const {
     return std::equal(this->data_.begin(), this->data_.begin() + OFFSET_CS, rhs.data_.begin());