[mitsubishi_cn105] Add Fahrenheit support (#15488)

Co-authored-by: J. Nick Koston <nick@koston.org>

esphome/components/mitsubishi_cn105/__init__.py

@@ -8,6 +8,7 @@ from esphome.const import (
     CONF_ON_STATE,
     CONF_TEMPERATURE,
     CONF_UPDATE_INTERVAL,
+    CONF_USE_FAHRENHEIT,
 )
 from esphome.core import ID, Lambda
 from esphome.cpp_generator import LambdaExpression, MockObj
@@ -71,6 +72,7 @@ CONFIG_SCHEMA = (
             cv.Optional(
                 CONF_TELEMETRY_REQUEST_MIN_INTERVAL, default="60s"
             ): cv.update_interval,
+            cv.Optional(CONF_USE_FAHRENHEIT, default=False): cv.boolean,
             cv.Optional(CONF_VANE): cv.Schema(
                 {
                     cv.Optional(CONF_ON_STATE): automation.validate_automation({}),
@@ -114,6 +116,7 @@ async def to_code(config: ConfigType) -> None:
             config[CONF_TELEMETRY_REQUEST_MIN_INTERVAL]
         )
     )
+    cg.add(var.set_use_fahrenheit(config[CONF_USE_FAHRENHEIT]))
     if on_state := config.get(CONF_VANE, {}).get(CONF_ON_STATE):
         cg.add_global(mitsubishi_ns.using)
         for conf in on_state:

esphome/components/mitsubishi_cn105/mitsubishi_cn105.h

@@ -83,6 +83,7 @@ class MitsubishiCN105 {
     return this->is_telemetry_polling_enabled() ? !std::isnan(this->status_.room_temperature)
                                                 : !std::isnan(this->status_.target_temperature);
   }
+  bool is_temperature_encoding_b() const { return this->property_context_.use_temperature_encoding_b; }
 
   void set_power(bool power_on);
   void set_target_temperature(float target_temperature);

esphome/components/mitsubishi_cn105/mitsubishi_cn105_climate.cpp

@@ -50,7 +50,11 @@ static constexpr std::optional<Left> reverse_map_lookup(const std::array<std::pa
   return key.has_value() ? reverse_map_lookup(map, *key) : std::nullopt;
 }
 
-void MitsubishiCN105Climate::dump_config() { LOG_CLIMATE("", "Mitsubishi CN105 Climate", this); }
+void MitsubishiCN105Climate::dump_config() {
+  LOG_CLIMATE("", "Mitsubishi CN105 Climate", this);
+  ESP_LOGCONFIG(TAG, "  Temperature unit: °%c",
+                this->parent_->get_temperature_mapping().get_use_fahrenheit() ? 'F' : 'C');
+}
 
 void MitsubishiCN105Climate::setup() {
   this->parent_->add_on_status_callback([this]() { this->apply_values_(); });
@@ -72,13 +76,15 @@ climate::ClimateTraits MitsubishiCN105Climate::traits() {
 
   traits.set_supported_swing_modes(this->supported_swing_modes_);
 
-  traits.set_visual_min_temperature(16.0f);
+  const bool use_fahrenheit = this->parent_->get_temperature_mapping().get_use_fahrenheit();
-  traits.set_visual_max_temperature(31.0f);
+  traits.set_temperature_unit(use_fahrenheit ? TemperatureUnit::FAHRENHEIT : TemperatureUnit::CELSIUS);
+  traits.set_visual_min_temperature(use_fahrenheit ? 61.0f : 16.0f);
+  traits.set_visual_max_temperature(use_fahrenheit ? 88.0f : 31.0f);
   traits.set_visual_temperature_step(1.0f);
 
   if (this->parent_->is_telemetry_polling_enabled()) {
     traits.add_feature_flags(climate::CLIMATE_SUPPORTS_CURRENT_TEMPERATURE);
-    traits.set_visual_current_temperature_step(0.5f);
+    traits.set_visual_current_temperature_step(use_fahrenheit ? 1.0f : 0.5f);
   }
 
   return traits;
@@ -86,7 +92,7 @@ climate::ClimateTraits MitsubishiCN105Climate::traits() {
 
 void MitsubishiCN105Climate::control(const climate::ClimateCall &call) {
   if (const auto target_temperature = call.get_target_temperature()) {
-    this->parent_->set_target_temperature(*target_temperature);
+    this->parent_->set_target_temperature(this->parent_->get_temperature_mapping().to_mitsubishi(*target_temperature));
   }
 
   if (const auto mode = call.get_mode()) {
@@ -139,10 +145,10 @@ void MitsubishiCN105Climate::control(const climate::ClimateCall &call) {
 void MitsubishiCN105Climate::apply_values_() {
   const auto &status = this->parent_->status();
 
-  this->target_temperature = status.target_temperature;
+  this->target_temperature = this->parent_->get_temperature_mapping().from_mitsubishi(status.target_temperature);
 
   if (this->parent_->is_telemetry_polling_enabled()) {
-    this->current_temperature = status.room_temperature;
+    this->current_temperature = this->parent_->get_temperature_mapping().from_mitsubishi(status.room_temperature);
   }
 
   if (status.power_on) {

esphome/components/mitsubishi_cn105/mitsubishi_cn105_component.cpp

@@ -27,6 +27,13 @@ void MitsubishiCN105Component::setup() { this->hp_.initialize(); }
 
 void MitsubishiCN105Component::loop() {
   if (this->hp_.update()) {
+    // Encoding A only supports whole °C values and cannot represent native °F setpoints accurately.
+    // See https://github.com/esphome/esphome/pull/15488#issuecomment-5268304343
+    if (this->temperature_mapping_.get_use_fahrenheit() && !this->hp_.is_temperature_encoding_b()) {
+      ESP_LOGE(TAG, "Unit reports encoding A, which cannot accurately convert °F setpoints; disable 'use_fahrenheit'");
+      this->mark_failed();
+      return;
+    }
     this->notify_status_listeners_();
   }
 }

esphome/components/mitsubishi_cn105/mitsubishi_cn105_component.h

@@ -3,13 +3,43 @@
 #include "mitsubishi_cn105.h"
 
 #include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
 #include "esphome/components/uart/uart.h"
 
-#include <utility>
+#include <algorithm>
+#include <cmath>
 #include <optional>
+#include <utility>
 
 namespace esphome::mitsubishi_cn105 {
 
+struct TemperatureMapping {
+  float to_mitsubishi(float value) const {
+    if (!this->use_fahrenheit_) {
+      return value;
+    }
+    const int fahrenheit = std::clamp(static_cast<int>(std::round(value)), 61, 88);
+    return 0.5f * (fahrenheit - 28 + (fahrenheit > 68) - (fahrenheit < 68));
+  }
+
+  float from_mitsubishi(float value) const {
+    if (!this->use_fahrenheit_) {
+      return value;
+    }
+    if (value < 16.0f || value > 30.5f) {
+      return celsius_to_fahrenheit(value);
+    }
+    const int mitsubishi_half_degrees = static_cast<int>(std::round(value * 2.0f));
+    return mitsubishi_half_degrees + 29 - (mitsubishi_half_degrees >= 40) - (mitsubishi_half_degrees > 40);
+  }
+
+  bool get_use_fahrenheit() const { return this->use_fahrenheit_; }
+  void set_use_fahrenheit(bool value) { this->use_fahrenheit_ = value; }
+
+ protected:
+  bool use_fahrenheit_{false};
+};
+
 enum VerticalVaneMode : uint8_t {
   VERTICAL_VANE_MODE_AUTO = static_cast<uint8_t>(MitsubishiCN105::VaneMode::AUTO),
   VERTICAL_VANE_MODE_POSITION_1 = static_cast<uint8_t>(MitsubishiCN105::VaneMode::POSITION_1),
@@ -60,6 +90,7 @@ class MitsubishiCN105Component : public Component, public uart::UARTDevice {
 
   void set_update_interval(uint32_t ms) { this->hp_.set_update_interval(ms); }
   void set_telemetry_request_min_interval(uint32_t ms) { this->hp_.set_telemetry_request_min_interval(ms); }
+  void set_use_fahrenheit(bool value) { this->temperature_mapping_.set_use_fahrenheit(value); }
 
   void set_remote_temperature(float temperature) { this->hp_.set_remote_temperature(temperature); }
   void clear_remote_temperature() { this->hp_.clear_remote_temperature(); }
@@ -75,6 +106,7 @@ class MitsubishiCN105Component : public Component, public uart::UARTDevice {
   const MitsubishiCN105::Status &status() const { return this->hp_.status(); }
   bool is_status_initialized() const { return this->hp_.is_status_initialized(); }
   bool is_telemetry_polling_enabled() const { return this->hp_.is_telemetry_polling_enabled(); }
+  const TemperatureMapping &get_temperature_mapping() const { return this->temperature_mapping_; }
 
   template<typename F> void add_on_status_callback(F &&callback) {
     this->status_callback_.add(std::forward<F>(callback));
@@ -99,6 +131,7 @@ class MitsubishiCN105Component : public Component, public uart::UARTDevice {
   }
 
   MitsubishiCN105 hp_;
+  TemperatureMapping temperature_mapping_;
   CallbackManager<void()> status_callback_;
   LazyCallbackManager<void(const VaneState &)> vane_state_callback_;
 };

esphome/components/mqtt/mqtt_climate.cpp

@@ -118,8 +118,7 @@ void MQTTClimateComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCo
   root[MQTT_TARGET_TEMPERATURE_STEP] = roundf(traits.get_visual_target_temperature_step() * 10) * 0.1f;
   // current_temp_step
   root[MQTT_CURRENT_TEMPERATURE_STEP] = roundf(traits.get_visual_current_temperature_step() * 10) * 0.1f;
-  // temperature units are always coerced to Celsius internally
+  root[MQTT_TEMPERATURE_UNIT] = traits.get_temperature_unit() == TemperatureUnit::FAHRENHEIT ? "F" : "C";
-  root[MQTT_TEMPERATURE_UNIT] = "C";
 
   // min_humidity
   root[MQTT_MIN_HUMIDITY] = traits.get_visual_min_humidity();

tests/components/mitsubishi_cn105/climate/mitsubishi_cn105_climate_tests.cpp

@@ -1,7 +1,67 @@
+#include <array>
+#include <utility>
 #include "../common.h"
 
 namespace esphome::mitsubishi_cn105::testing {
 
+TEST(MitsubishiCN105ClimateTests, CelsiusTemperatureMappingAndTraitsMatchExpectedValues) {
+  TestableMitsubishiCN105Climate sut;
+  const auto mapping = TemperatureMapping();
+
+  for (int temperature = 16; temperature <= 31; ++temperature) {
+    EXPECT_EQ(mapping.to_mitsubishi(temperature), temperature);
+    EXPECT_EQ(mapping.from_mitsubishi(temperature), temperature);
+  }
+
+  const auto traits = sut.traits();
+  EXPECT_EQ(traits.get_temperature_unit(), TemperatureUnit::CELSIUS);
+  EXPECT_FLOAT_EQ(traits.get_visual_min_temperature(), 16.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_max_temperature(), 31.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_target_temperature_step(), 1.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_current_temperature_step(), 0.5f);
+}
+
+TEST(MitsubishiCN105ClimateTests, FahrenheitTemperatureMappingAndTraitsMatchExpectedValues) {
+  TestableMitsubishiCN105Climate sut;
+  auto mapping = TemperatureMapping();
+  mapping.set_use_fahrenheit(true);
+  sut.set_use_fahrenheit(true);
+
+  const std::array cases{
+      std::pair{61, 16.0f}, std::pair{62, 16.5f}, std::pair{63, 17.0f}, std::pair{64, 17.5f}, std::pair{65, 18.0f},
+      std::pair{66, 18.5f}, std::pair{67, 19.0f}, std::pair{68, 20.0f}, std::pair{69, 21.0f}, std::pair{70, 21.5f},
+      std::pair{71, 22.0f}, std::pair{72, 22.5f}, std::pair{73, 23.0f}, std::pair{74, 23.5f}, std::pair{75, 24.0f},
+      std::pair{76, 24.5f}, std::pair{77, 25.0f}, std::pair{78, 25.5f}, std::pair{79, 26.0f}, std::pair{80, 26.5f},
+      std::pair{81, 27.0f}, std::pair{82, 27.5f}, std::pair{83, 28.0f}, std::pair{84, 28.5f}, std::pair{85, 29.0f},
+      std::pair{86, 29.5f}, std::pair{87, 30.0f}, std::pair{88, 30.5f},
+  };
+
+  for (const auto &[fahrenheit, mitsubishi_celsius] : cases) {
+    EXPECT_FLOAT_EQ(mapping.to_mitsubishi(fahrenheit), mitsubishi_celsius);
+    EXPECT_FLOAT_EQ(mapping.from_mitsubishi(mitsubishi_celsius), fahrenheit);
+  }
+  const auto traits = sut.traits();
+  EXPECT_EQ(traits.get_temperature_unit(), TemperatureUnit::FAHRENHEIT);
+  EXPECT_FLOAT_EQ(traits.get_visual_min_temperature(), 61.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_max_temperature(), 88.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_target_temperature_step(), 1.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_current_temperature_step(), 1.0f);
+}
+
+TEST(MitsubishiCN105ClimateTests, FahrenheitTemperatureMappingUsesLinearConversionOutsideSetpointRange) {
+  auto mapping = TemperatureMapping();
+  mapping.set_use_fahrenheit(true);
+
+  const std::array cases{
+      std::pair{0.0f, 32.0f},  std::pair{10.0f, 50.0f}, std::pair{15.5f, 59.9f},
+      std::pair{31.0f, 87.8f}, std::pair{35.0f, 95.0f}, std::pair{40.0f, 104.0f},
+  };
+
+  for (const auto &[celsius, fahrenheit] : cases) {
+    EXPECT_FLOAT_EQ(mapping.from_mitsubishi(celsius), fahrenheit);
+  }
+}
+
 TEST(MitsubishiCN105ClimateTests, SupportedSwingModeOffLeavesTraitsEmpty) {
   TestableMitsubishiCN105Climate sut;
 

tests/components/mitsubishi_cn105/common.h

@@ -73,6 +73,7 @@ class TestableMitsubishiCN105Climate : public MitsubishiCN105Climate {
   using MitsubishiCN105Climate::last_non_swing_wide_vane_mode_;
 
   MitsubishiCN105::Status &status() { return const_cast<MitsubishiCN105::Status &>(this->component_.status()); }
+  void set_use_fahrenheit(bool value) { this->component_.set_use_fahrenheit(value); }
 
  protected:
   MitsubishiCN105Component component_;

tests/components/mitsubishi_cn105/common.yaml

@@ -3,6 +3,7 @@ mitsubishi_cn105:
   uart_id: uart_bus
   update_interval: 30s
   telemetry_request_min_interval: 120s
+  use_fahrenheit: true
   vane:
     on_state:
       - logger.log: