[dew_point] Add dew_point sensor component (#14441)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

CODEOWNERS

@@ -132,6 +132,7 @@ esphome/components/dashboard_import/* @esphome/core
 esphome/components/datetime/* @jesserockz @rfdarter
 esphome/components/debug/* @esphome/core
 esphome/components/delonghi/* @grob6000
+esphome/components/dew_point/* @CFlix
 esphome/components/dfplayer/* @glmnet
 esphome/components/dfrobot_sen0395/* @niklasweber
 esphome/components/dht/* @OttoWinter

esphome/components/dew_point/__init__.py

@@ -0,0 +1 @@
+CODEOWNERS = ["@CFlix"]

esphome/components/dew_point/dew_point.cpp

@@ -0,0 +1,82 @@
+
+#include "dew_point.h"
+
+namespace esphome::dew_point {
+
+static const char *const TAG = "dew_point.sensor";
+
+void DewPointComponent::setup() {
+  // Register callbacks for sensor updates
+  if (this->temperature_sensor_ != nullptr) {
+    this->temperature_sensor_->add_on_state_callback([this](float state) {
+      this->temperature_value_ = state;
+      this->enable_loop();
+    });
+    // Get initial value
+    if (this->temperature_sensor_->has_state()) {
+      this->temperature_value_ = this->temperature_sensor_->get_state();
+    }
+  }
+
+  if (this->humidity_sensor_ != nullptr) {
+    this->humidity_sensor_->add_on_state_callback([this](float state) {
+      this->humidity_value_ = state;
+      this->enable_loop();
+    });
+    // Get initial value
+    if (this->humidity_sensor_->has_state()) {
+      this->humidity_value_ = this->humidity_sensor_->get_state();
+    }
+  }
+}
+
+void DewPointComponent::dump_config() {
+  LOG_SENSOR("", "Dew Point", this);
+  ESP_LOGCONFIG(TAG,
+                "Sources\n"
+                "  Temperature: '%s'\n"
+                "  Humidity: '%s'",
+                this->temperature_sensor_->get_name().c_str(), this->humidity_sensor_->get_name().c_str());
+}
+
+float DewPointComponent::get_setup_priority() const { return setup_priority::DATA; }
+
+void DewPointComponent::loop() {
+  // Only run once
+  this->disable_loop();
+
+  // Check if we have valid values for both sensors
+  if (std::isnan(this->temperature_value_) || std::isnan(this->humidity_value_)) {
+    ESP_LOGW(TAG, "Temperature or humidity value is NaN, skipping calculation");
+    this->publish_state(NAN);
+    return;
+  }
+
+  // Check for valid humidity range
+  if (this->humidity_value_ <= 0.0f || this->humidity_value_ > 100.0f) {
+    ESP_LOGW(TAG, "Humidity value out of range (0-100): %.2f", this->humidity_value_);
+    this->publish_state(NAN);
+    return;
+  }
+
+  // Magnus formula constants
+  const float a{17.625f};
+  const float b{243.04f};
+
+  // Calculate dew point using Magnus formula
+  // Td = (b * alpha) / (a - alpha)
+  // where alpha = ln(RH/100) + (a * T) / (b + T)
+
+  const float alpha{std::log(this->humidity_value_ / 100.0f) +
+                    (a * this->temperature_value_) / (b + this->temperature_value_)};
+
+  const float dew_point{(b * alpha) / (a - alpha)};
+
+  // Publish the calculated dew point
+  this->publish_state(dew_point);
+
+  ESP_LOGD(TAG, "'%s' >> %.1f°C (T: %.1f°C, RH: %.1f%%)", this->get_name().c_str(), dew_point, this->temperature_value_,
+           this->humidity_value_);
+}
+
+}  // namespace esphome::dew_point

esphome/components/dew_point/dew_point.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+
+namespace esphome::dew_point {
+
+class DewPointComponent : public Component, public sensor::Sensor {
+ public:
+  void set_temperature_sensor(sensor::Sensor *temperature_sensor) { this->temperature_sensor_ = temperature_sensor; }
+  void set_humidity_sensor(sensor::Sensor *humidity_sensor) { this->humidity_sensor_ = humidity_sensor; }
+
+  void setup() override;
+  void dump_config() override;
+  void loop() override;
+
+  float get_setup_priority() const override;
+
+ protected:
+  sensor::Sensor *temperature_sensor_{nullptr};
+  sensor::Sensor *humidity_sensor_{nullptr};
+  float temperature_value_{NAN};
+  float humidity_value_{NAN};
+};
+
+}  // namespace esphome::dew_point

esphome/components/dew_point/sensor.py

@@ -0,0 +1,46 @@
+import esphome.codegen as cg
+from esphome.components import sensor
+import esphome.config_validation as cv
+from esphome.const import (
+    CONF_HUMIDITY,
+    CONF_TEMPERATURE,
+    DEVICE_CLASS_TEMPERATURE,
+    STATE_CLASS_MEASUREMENT,
+    UNIT_CELSIUS,
+)
+
+DEPENDENCIES = ["sensor"]
+
+dew_point_ns = cg.esphome_ns.namespace("dew_point")
+DewPointComponent = dew_point_ns.class_(
+    "DewPointComponent", cg.Component, sensor.Sensor
+)
+
+CONFIG_SCHEMA = (
+    sensor.sensor_schema(
+        DewPointComponent,
+        unit_of_measurement=UNIT_CELSIUS,
+        accuracy_decimals=1,
+        device_class=DEVICE_CLASS_TEMPERATURE,
+        state_class=STATE_CLASS_MEASUREMENT,
+        icon="mdi:weather-rainy",
+    )
+    .extend(
+        {
+            cv.Required(CONF_TEMPERATURE): cv.use_id(sensor.Sensor),
+            cv.Required(CONF_HUMIDITY): cv.use_id(sensor.Sensor),
+        }
+    )
+    .extend(cv.COMPONENT_SCHEMA)
+)
+
+
+async def to_code(config):
+    var = await sensor.new_sensor(config)
+    await cg.register_component(var, config)
+
+    temperature_sensor = await cg.get_variable(config[CONF_TEMPERATURE])
+    cg.add(var.set_temperature_sensor(temperature_sensor))
+
+    humidity_sensor = await cg.get_variable(config[CONF_HUMIDITY])
+    cg.add(var.set_humidity_sensor(humidity_sensor))

tests/components/dew_point/common.yaml

@@ -0,0 +1,19 @@
+sensor:
+  - platform: dew_point
+    name: Dew Point
+    temperature: template_temperature
+    humidity: template_humidity
+  - platform: template
+    id: template_humidity
+    lambda: |-
+      if (millis() > 10000) {
+        return 0.6;
+      }
+      return 0.0;
+  - platform: template
+    id: template_temperature
+    lambda: |-
+      if (millis() > 10000) {
+        return 42.0;
+      }
+      return 0.0;

tests/components/dew_point/test.esp32-idf.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/dew_point/test.esp8266-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/dew_point/test.rp2040-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml