Add support for SHT4X (#1512)

CODEOWNERS

@@ -80,6 +80,7 @@ esphome/components/rtttl/* @glmnet
 esphome/components/script/* @esphome/core
 esphome/components/sensor/* @esphome/core
 esphome/components/sgp40/* @SenexCrenshaw
+esphome/components/sht4x/* @sjtrny
 esphome/components/shutdown/* @esphome/core
 esphome/components/sim800l/* @glmnet
 esphome/components/spi/* @esphome/core

esphome/components/sht4x/sensor.py

@@ -0,0 +1,92 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import i2c, sensor
+from esphome.const import (
+    CONF_ID,
+    CONF_TEMPERATURE,
+    CONF_HUMIDITY,
+    UNIT_CELSIUS,
+    UNIT_PERCENT,
+    ICON_THERMOMETER,
+    ICON_WATER_PERCENT,
+    DEVICE_CLASS_TEMPERATURE,
+    DEVICE_CLASS_HUMIDITY,
+)
+
+CODEOWNERS = ["@sjtrny"]
+DEPENDENCIES = ["i2c"]
+
+sht4x_ns = cg.esphome_ns.namespace("sht4x")
+
+SHT4XComponent = sht4x_ns.class_("SHT4XComponent", cg.PollingComponent, i2c.I2CDevice)
+
+CONF_PRECISION = "precision"
+SHT4XPRECISION = sht4x_ns.enum("SHT4XPRECISION")
+PRECISION_OPTIONS = {
+    "High": SHT4XPRECISION.SHT4X_PRECISION_HIGH,
+    "Med": SHT4XPRECISION.SHT4X_PRECISION_MED,
+    "Low": SHT4XPRECISION.SHT4X_PRECISION_LOW,
+}
+
+CONF_HEATER_POWER = "heater_power"
+SHT4XHEATERPOWER = sht4x_ns.enum("SHT4XHEATERPOWER")
+HEATER_POWER_OPTIONS = {
+    "High": SHT4XHEATERPOWER.SHT4X_HEATERPOWER_HIGH,
+    "Med": SHT4XHEATERPOWER.SHT4X_HEATERPOWER_MED,
+    "Low": SHT4XHEATERPOWER.SHT4X_HEATERPOWER_LOW,
+}
+
+CONF_HEATER_TIME = "heater_time"
+SHT4XHEATERTIME = sht4x_ns.enum("SHT4XHEATERTIME")
+HEATER_TIME_OPTIONS = {
+    "Long": SHT4XHEATERTIME.SHT4X_HEATERTIME_LONG,
+    "Short": SHT4XHEATERTIME.SHT4X_HEATERTIME_SHORT,
+}
+
+CONF_HEATER_MAX_DUTY = "heater_max_duty"
+
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(SHT4XComponent),
+            cv.Optional(CONF_TEMPERATURE): sensor.sensor_schema(
+                UNIT_CELSIUS, ICON_THERMOMETER, 2, DEVICE_CLASS_TEMPERATURE
+            ),
+            cv.Optional(CONF_HUMIDITY): sensor.sensor_schema(
+                UNIT_PERCENT, ICON_WATER_PERCENT, 2, DEVICE_CLASS_HUMIDITY
+            ),
+            cv.Optional(CONF_PRECISION, default="High"): cv.enum(PRECISION_OPTIONS),
+            cv.Optional(CONF_HEATER_POWER, default="High"): cv.enum(
+                HEATER_POWER_OPTIONS
+            ),
+            cv.Optional(CONF_HEATER_TIME, default="Long"): cv.enum(HEATER_TIME_OPTIONS),
+            cv.Optional(CONF_HEATER_MAX_DUTY, default=0.0): cv.float_range(
+                min=0.0, max=0.05
+            ),
+        }
+    )
+    .extend(cv.polling_component_schema("60s"))
+    .extend(i2c.i2c_device_schema(0x44))
+)
+
+TYPES = {
+    CONF_TEMPERATURE: "set_temp_sensor",
+    CONF_HUMIDITY: "set_humidity_sensor",
+}
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield i2c.register_i2c_device(var, config)
+
+    cg.add(var.set_precision_value(config[CONF_PRECISION]))
+    cg.add(var.set_heater_power_value(config[CONF_HEATER_POWER]))
+    cg.add(var.set_heater_time_value(config[CONF_HEATER_TIME]))
+    cg.add(var.set_heater_duty_value(config[CONF_HEATER_MAX_DUTY]))
+
+    for key, funcName in TYPES.items():
+
+        if key in config:
+            sens = yield sensor.new_sensor(config[key])
+            cg.add(getattr(var, funcName)(sens))

esphome/components/sht4x/sht4x.cpp

@@ -0,0 +1,89 @@
+#include "sht4x.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace sht4x {
+
+static const char *TAG = "sht4x";
+
+static const uint8_t MEASURECOMMANDS[] = {0xFD, 0xF6, 0xE0};
+
+void SHT4XComponent::start_heater_() {
+  uint8_t cmd[] = {MEASURECOMMANDS[this->heater_command_]};
+
+  ESP_LOGD(TAG, "Heater turning on");
+  this->write_bytes_raw(cmd, 1);
+}
+
+void SHT4XComponent::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up sht4x...");
+
+  if (this->duty_cycle_ > 0.0) {
+    uint32_t heater_interval = (uint32_t)(this->heater_time_ / this->duty_cycle_);
+    ESP_LOGD(TAG, "Heater interval: %i", heater_interval);
+
+    if (this->heater_power_ == SHT4X_HEATERPOWER_HIGH) {
+      if (this->heater_time_ == SHT4X_HEATERTIME_LONG) {
+        this->heater_command_ = 0x39;
+      } else {
+        this->heater_command_ = 0x32;
+      }
+    } else if (this->heater_power_ == SHT4X_HEATERPOWER_MED) {
+      if (this->heater_time_ == SHT4X_HEATERTIME_LONG) {
+        this->heater_command_ = 0x2F;
+      } else {
+        this->heater_command_ = 0x24;
+      }
+    } else {
+      if (this->heater_time_ == SHT4X_HEATERTIME_LONG) {
+        this->heater_command_ = 0x1E;
+      } else {
+        this->heater_command_ = 0x15;
+      }
+    }
+    ESP_LOGD(TAG, "Heater command: %x", this->heater_command_);
+
+    this->set_interval(heater_interval, std::bind(&SHT4XComponent::start_heater_, this));
+  }
+}
+
+void SHT4XComponent::dump_config() { LOG_I2C_DEVICE(this); }
+
+void SHT4XComponent::update() {
+  uint8_t cmd[] = {MEASURECOMMANDS[this->precision_]};
+
+  // Send command
+  this->write_bytes_raw(cmd, 1);
+
+  this->set_timeout(10, [this]() {
+    const uint8_t num_bytes = 6;
+    uint8_t buffer[num_bytes];
+
+    // Read measurement
+    bool read_status = this->read_bytes_raw(buffer, num_bytes);
+
+    if (read_status) {
+      // Evaluate and publish measurements
+      if (this->temp_sensor_ != nullptr) {
+        // Temp is contained in the first 16 bits
+        float sensor_value_temp = (buffer[0] << 8) + buffer[1];
+        float temp = -45 + 175 * sensor_value_temp / 65535;
+
+        this->temp_sensor_->publish_state(temp);
+      }
+
+      if (this->humidity_sensor_ != nullptr) {
+        // Relative humidity is in the last 16 bits
+        float sensor_value_rh = (buffer[3] << 8) + buffer[4];
+        float rh = -6 + 125 * sensor_value_rh / 65535;
+
+        this->humidity_sensor_->publish_state(rh);
+      }
+    } else {
+      ESP_LOGD(TAG, "Sensor read failed");
+    }
+  });
+}
+
+}  // namespace sht4x
+}  // namespace esphome

esphome/components/sht4x/sht4x.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/i2c/i2c.h"
+
+namespace esphome {
+namespace sht4x {
+
+enum SHT4XPRECISION { SHT4X_PRECISION_HIGH = 0, SHT4X_PRECISION_MED, SHT4X_PRECISION_LOW };
+
+enum SHT4XHEATERPOWER { SHT4X_HEATERPOWER_HIGH, SHT4X_HEATERPOWER_MED, SHT4X_HEATERPOWER_LOW };
+
+enum SHT4XHEATERTIME { SHT4X_HEATERTIME_LONG = 1100, SHT4X_HEATERTIME_SHORT = 110 };
+
+class SHT4XComponent : public PollingComponent, public i2c::I2CDevice {
+ public:
+  float get_setup_priority() const override { return setup_priority::DATA; }
+  void setup() override;
+  void dump_config() override;
+  void update() override;
+
+  void set_precision_value(SHT4XPRECISION precision) { this->precision_ = precision; };
+  void set_heater_power_value(SHT4XHEATERPOWER heater_power) { this->heater_power_ = heater_power; };
+  void set_heater_time_value(SHT4XHEATERTIME heater_time) { this->heater_time_ = heater_time; };
+  void set_heater_duty_value(float duty_cycle) { this->duty_cycle_ = duty_cycle; };
+
+  void set_temp_sensor(sensor::Sensor *temp_sensor) { this->temp_sensor_ = temp_sensor; }
+  void set_humidity_sensor(sensor::Sensor *humidity_sensor) { this->humidity_sensor_ = humidity_sensor; }
+
+ protected:
+  SHT4XPRECISION precision_;
+  SHT4XHEATERPOWER heater_power_;
+  SHT4XHEATERTIME heater_time_;
+  float duty_cycle_;
+
+  void start_heater_();
+  uint8_t heater_command_;
+
+  sensor::Sensor *temp_sensor_{nullptr};
+  sensor::Sensor *humidity_sensor_{nullptr};
+};
+
+}  // namespace sht4x
+}  // namespace esphome

tests/test1.yaml

@@ -741,6 +741,13 @@ sensor:
       id: 'workshop_PMC_10_0'
     address: 0x69
     update_interval: 10s
+  - platform: sht4x
+    temperature:
+      name: 'SHT4X Temperature'
+    humidity:
+      name: 'SHT4X Humidity'
+    address: 0x44
+    update_interval: 15s
   - platform: shtcx
     temperature:
       name: 'Living Room Temperature 10'