[mitsubishi] Add fahrenheit_compatibility mode (#18880)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>
Co-authored-by: J. Nick Koston <nick@koston.org>

esphome/components/mitsubishi/climate.py

@@ -20,6 +20,7 @@ SETFANMODE = {
 
 CONF_SUPPORTS_DRY = "supports_dry"
 CONF_SUPPORTS_FAN_ONLY = "supports_fan_only"
+CONF_FAHRENHEIT_COMPATIBILITY = "fahrenheit_compatibility"
 
 CONF_HORIZONTAL_DEFAULT = "horizontal_default"
 HorizontalDirections = mitsubishi_ns.enum("HorizontalDirections")
@@ -49,6 +50,7 @@ CONFIG_SCHEMA = climate_ir.climate_ir_with_receiver_schema(MitsubishiClimate).ex
         cv.Optional(CONF_SET_FAN_MODE, default="3levels"): cv.enum(SETFANMODE),
         cv.Optional(CONF_SUPPORTS_DRY, default=False): cv.boolean,
         cv.Optional(CONF_SUPPORTS_FAN_ONLY, default=False): cv.boolean,
+        cv.Optional(CONF_FAHRENHEIT_COMPATIBILITY, default=False): cv.boolean,
         cv.Optional(CONF_HORIZONTAL_DEFAULT, default="middle"): cv.enum(
             HORIZONTAL_DIRECTIONS
         ),
@@ -65,5 +67,6 @@ async def to_code(config: ConfigType) -> None:
     cg.add(var.set_fan_mode(config[CONF_SET_FAN_MODE]))
     cg.add(var.set_supports_dry(config[CONF_SUPPORTS_DRY]))
     cg.add(var.set_supports_fan_only(config[CONF_SUPPORTS_FAN_ONLY]))
+    cg.add(var.set_fahrenheit_compatibility(config[CONF_FAHRENHEIT_COMPATIBILITY]))
     cg.add(var.set_horizontal_default(config[CONF_HORIZONTAL_DEFAULT]))
     cg.add(var.set_vertical_default(config[CONF_VERTICAL_DEFAULT]))

esphome/components/mitsubishi/mitsubishi.cpp

@@ -1,4 +1,5 @@
 #include "mitsubishi.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -53,6 +54,33 @@ const uint8_t MITSUBISHI_BYTE04 = 0x00;
 const uint8_t MITSUBISHI_BYTE13 = 0x00;
 const uint8_t MITSUBISHI_BYTE16 = 0x00;
 
+// Byte 7 codes for 61°F through 88°F. Bit 4 is the half degree bit Mitsubishi uses so every Fahrenheit degree
+// maps to its own code.
+static const uint8_t FAHRENHEIT_CODES[] PROGMEM = {0x00, 0x10, 0x01, 0x11, 0x02, 0x12, 0x03, 0x04, 0x05, 0x15,
+                                                   0x06, 0x16, 0x07, 0x17, 0x08, 0x18, 0x09, 0x19, 0x0a, 0x1a,
+                                                   0x0b, 0x1b, 0x0c, 0x1c, 0x0d, 0x1d, 0x0e, 0x0f};
+static constexpr uint8_t FAHRENHEIT_MIN = 61;
+static constexpr uint8_t MITSUBISHI_HALF_DEGREE = 0x10;
+
+static uint8_t fahrenheit_code(float celsius) {
+  int fahrenheit = (int) roundf(celsius_to_fahrenheit(celsius));
+  size_t index = clamp<int>(fahrenheit - FAHRENHEIT_MIN, 0, sizeof(FAHRENHEIT_CODES) - 1);
+  return progmem_read_byte(&FAHRENHEIT_CODES[index]);
+}
+
+// In Fahrenheit mode a code from the table decodes to the exact Fahrenheit value. Any other code, and every code in
+// Celsius mode, is a whole degree plus the half degree bit, which a remote set to Fahrenheit also sets.
+static float decode_temperature(uint8_t code, bool fahrenheit) {
+  if (fahrenheit) {
+    for (size_t i = 0; i < sizeof(FAHRENHEIT_CODES); i++) {
+      if (code == progmem_read_byte(&FAHRENHEIT_CODES[i])) {
+        return fahrenheit_to_celsius(FAHRENHEIT_MIN + i);
+      }
+    }
+  }
+  return MITSUBISHI_TEMP_MIN + (code & 0x0F) + ((code & MITSUBISHI_HALF_DEGREE) ? 0.5f : 0.0f);
+}
+
 void MitsubishiClimate::transmit_state() {
   // Byte 0-4: Constant: 0x23, 0xCB, 0x26, 0x01, 0x00
   // Byte 5: On=0x20, Off: 0x00
@@ -113,6 +141,8 @@ void MitsubishiClimate::transmit_state() {
   // Temperature
   if (this->mode == climate::CLIMATE_MODE_DRY) {
     remote_state[7] = 24 - MITSUBISHI_TEMP_MIN;  // Remote sends always 24°C if "Dry" mode is selected
+  } else if (this->fahrenheit_compatibility_) {
+    remote_state[7] = fahrenheit_code(this->target_temperature);
   } else {
     remote_state[7] = (uint8_t) roundf(
         clamp<float>(this->target_temperature, MITSUBISHI_TEMP_MIN, MITSUBISHI_TEMP_MAX) - MITSUBISHI_TEMP_MIN);
@@ -300,7 +330,7 @@ bool MitsubishiClimate::on_receive(remote_base::RemoteReceiveData data) {
   }
 
   // Temp
-  this->target_temperature = state_frame[7] + MITSUBISHI_TEMP_MIN;
+  this->target_temperature = decode_temperature(state_frame[7], this->fahrenheit_compatibility_);
 
   // Fan
   uint8_t fan = state_frame[9] & 0x07;  //(Bit 0,1,2 = Speed)

esphome/components/mitsubishi/mitsubishi.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "esphome/components/climate_ir/climate_ir.h"
+#include "esphome/core/helpers.h"
 
 #include <cinttypes>
 
@@ -9,6 +10,8 @@ namespace esphome::mitsubishi {
 // Temperature
 const uint8_t MITSUBISHI_TEMP_MIN = 16;  // Celsius
 const uint8_t MITSUBISHI_TEMP_MAX = 31;  // Celsius
+// Remotes set to Fahrenheit go up to 88°F, one step past the Celsius range
+static constexpr float MITSUBISHI_TEMP_MAX_FAHRENHEIT = fahrenheit_to_celsius(88.0f);
 
 // Fan mode
 enum SetFanMode : uint8_t {
@@ -55,6 +58,12 @@ class MitsubishiClimate final : public climate_ir::ClimateIR {
   void set_supports_fan_only(bool supports_fan_only) {
     this->set_mode_supported_(climate::CLIMATE_MODE_FAN_ONLY, supports_fan_only);
   }
+  void set_fahrenheit_compatibility(bool fahrenheit_compatibility) {
+    this->fahrenheit_compatibility_ = fahrenheit_compatibility;
+    if (fahrenheit_compatibility) {
+      this->maximum_temperature_ = MITSUBISHI_TEMP_MAX_FAHRENHEIT;
+    }
+  }
 
   void set_fan_mode(SetFanMode fan_mode) {
     this->fan_mode_ = fan_mode;
@@ -80,6 +89,7 @@ class MitsubishiClimate final : public climate_ir::ClimateIR {
   bool parse_state_frame_(const uint8_t frame[]);
 
   SetFanMode fan_mode_;
+  bool fahrenheit_compatibility_{false};
 
   HorizontalDirection default_horizontal_direction_;
   VerticalDirection default_vertical_direction_;

tests/components/mitsubishi/common.yaml

@@ -2,3 +2,7 @@ climate:
   - platform: mitsubishi
     name: Mitsubishi
     transmitter_id: xmitr
+    fahrenheit_compatibility: true
+  - platform: mitsubishi
+    name: Mitsubishi Celsius
+    transmitter_id: xmitr