Add support for SCD4X (#2217)

* Initial commit

* clang-format fixes

* Update CODEOWNERS

* clang-format fixes

* Fix merge error

* Fix missing return

Co-authored-by: Otto winter <otto@otto-winter.com>

esphome/components/scd4x/scd4x.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/i2c/i2c.h"
+
+namespace esphome {
+namespace scd4x {
+
+enum ERRORCODE { COMMUNICATION_FAILED, SERIAL_NUMBER_IDENTIFICATION_FAILED, MEASUREMENT_INIT_FAILED, UNKNOWN };
+
+class SCD4XComponent : 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_automatic_self_calibration(bool asc) { enable_asc_ = asc; }
+  void set_altitude_compensation(uint16_t altitude) { altitude_compensation_ = altitude; }
+  void set_ambient_pressure_compensation(float pressure) {
+    ambient_pressure_compensation_ = true;
+    ambient_pressure_ = (uint16_t)(pressure * 1000);
+  }
+  void set_temperature_offset(float offset) { temperature_offset_ = offset; };
+
+  void set_co2_sensor(sensor::Sensor *co2) { co2_sensor_ = co2; }
+  void set_temperature_sensor(sensor::Sensor *temperature) { temperature_sensor_ = temperature; };
+  void set_humidity_sensor(sensor::Sensor *humidity) { humidity_sensor_ = humidity; }
+
+ protected:
+  uint8_t sht_crc_(uint8_t data1, uint8_t data2);
+  bool read_data_(uint16_t *data, uint8_t len);
+  bool write_command_(uint16_t command);
+  bool write_command_(uint16_t command, uint16_t data);
+
+  ERRORCODE error_code_;
+
+  bool initialized_{false};
+
+  float temperature_offset_;
+  uint16_t altitude_compensation_;
+  bool ambient_pressure_compensation_;
+  uint16_t ambient_pressure_;
+  bool enable_asc_;
+
+  sensor::Sensor *co2_sensor_{nullptr};
+  sensor::Sensor *temperature_sensor_{nullptr};
+  sensor::Sensor *humidity_sensor_{nullptr};
+};
+
+}  // namespace scd4x
+}  // namespace esphome