esphome/esphome/components/sht4x/sht4x.cpp

#include "sht4x.h"
#include "esphome/core/log.h"

namespace esphome {
namespace sht4x {

static const char *const 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(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(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