htu21d.cpp

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#include "htu21d.h"
#include "esphome/core/log.h"
#include "esphome/core/hal.h"
 
namespace esphome::htu21d {
 
static const char *const TAG = "htu21d";
 
static const uint8_t HTU21D_ADDRESS = 0x40;
static const uint8_t HTU21D_REGISTER_RESET = 0xFE;
static const uint8_t HTU21D_REGISTER_TEMPERATURE = 0xF3;
static const uint8_t HTU21D_REGISTER_HUMIDITY = 0xF5;
static const uint8_t HTU21D_WRITERHT_REG_CMD = 0xE6; 
static const uint8_t HTU21D_REGISTER_STATUS = 0xE7;
static const uint8_t HTU21D_WRITEHEATER_REG_CMD = 0x51; 
static const uint8_t HTU21D_READHEATER_REG_CMD = 0x11;  
static const uint8_t HTU21D_REG_HTRE_BIT = 0x02;        
void HTU21DComponent::setup() {
  if (!this->write_bytes(HTU21D_REGISTER_RESET, nullptr, 0)) {
    this->mark_failed();
    return;
  }
 
  // Wait for software reset to complete
  delay(15);
}
void HTU21DComponent::dump_config() {
  ESP_LOGCONFIG(TAG, "HTU21D:");
  LOG_I2C_DEVICE(this);
  if (this->is_failed()) {
    ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL);
  }
  LOG_UPDATE_INTERVAL(this);
  LOG_SENSOR("  ", "Temperature", this->temperature_);
  LOG_SENSOR("  ", "Humidity", this->humidity_);
}
void HTU21DComponent::update() {
  if (this->write(&HTU21D_REGISTER_TEMPERATURE, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return;
  }
 
  // According to the datasheet sht21 temperature readings can take up to 85ms
  this->set_timeout(85, [this]() {
    uint16_t raw_temperature;
    if (this->read(reinterpret_cast<uint8_t *>(&raw_temperature), 2) != i2c::ERROR_OK) {
      this->status_set_warning();
      return;
    }
    raw_temperature = i2c::i2ctohs(raw_temperature);
 
    float temperature = (float(raw_temperature & 0xFFFC)) * 175.72f / 65536.0f - 46.85f;
 
    ESP_LOGD(TAG, "Got Temperature=%.1f°C", temperature);
 
    if (this->temperature_ != nullptr)
      this->temperature_->publish_state(temperature);
 
    if (this->write(&HTU21D_REGISTER_HUMIDITY, 1) != i2c::ERROR_OK) {
      this->status_set_warning();
      return;
    }
 
    this->set_timeout(50, [this]() {
      uint16_t raw_humidity;
      if (this->read(reinterpret_cast<uint8_t *>(&raw_humidity), 2) != i2c::ERROR_OK) {
        this->status_set_warning();
        return;
      }
      raw_humidity = i2c::i2ctohs(raw_humidity);
 
      float humidity = (float(raw_humidity & 0xFFFC)) * 125.0f / 65536.0f - 6.0f;
 
      ESP_LOGD(TAG, "Got Humidity=%.1f%%", humidity);
 
      if (this->humidity_ != nullptr)
        this->humidity_->publish_state(humidity);
 
      this->status_clear_warning();
 
      // HTU21D does have a heater module but does not have heater level
      // Setting heater level to 1 in case the heater is ON
      uint8_t heater_level = 0;
      if (this->sensor_model_ == HTU21D_SENSOR_MODEL_HTU21D) {
        if (this->is_heater_enabled()) {
          heater_level = 1;
        } else {
          heater_level = 0;
        }
      } else {
        heater_level = this->get_heater_level();
      }
 
      ESP_LOGD(TAG, "Heater Level=%d", heater_level);
 
      if (this->heater_ != nullptr)
        this->heater_->publish_state(heater_level);
    });
  });
}
 
bool HTU21DComponent::is_heater_enabled() {
  uint8_t raw_heater;
  if (this->read_register(HTU21D_REGISTER_STATUS, &raw_heater, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return false;
  }
  return (bool) ((raw_heater >> HTU21D_REG_HTRE_BIT) & 0x01);
}
 
void HTU21DComponent::set_heater(bool status) {
  uint8_t raw_heater;
  if (this->read_register(HTU21D_REGISTER_STATUS, &raw_heater, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return;
  }
  if (status) {
    raw_heater |= (1 << HTU21D_REG_HTRE_BIT);
  } else {
    raw_heater &= ~(1 << HTU21D_REG_HTRE_BIT);
  }
  if (this->write_register(HTU21D_WRITERHT_REG_CMD, &raw_heater, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return;
  }
}
 
void HTU21DComponent::set_heater_level(uint8_t level) {
  if (this->write_register(HTU21D_WRITEHEATER_REG_CMD, &level, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return;
  }
}
 
uint8_t HTU21DComponent::get_heater_level() {
  uint8_t raw_heater;
  if (this->read_register(HTU21D_READHEATER_REG_CMD, &raw_heater, 1) != i2c::ERROR_OK) {
    this->status_set_warning();
    return 0;
  }
  return raw_heater & 0xF;
}
 
}  // namespace esphome::htu21d