sen5x.cpp

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#include "sen5x.h"
#include "esphome/core/application.h"
#include "esphome/core/hal.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
#include <cinttypes>
 
namespace esphome::sen5x {
 
ESPHOME_LOG_TAG(TAG, "sen5x");
 
static const uint16_t SEN5X_CMD_AUTO_CLEANING_INTERVAL = 0x8004;
static const uint16_t SEN5X_CMD_GET_DATA_READY_STATUS = 0x0202;
static const uint16_t SEN5X_CMD_GET_FIRMWARE_VERSION = 0xD100;
static const uint16_t SEN5X_CMD_GET_PRODUCT_NAME = 0xD014;
static const uint16_t SEN5X_CMD_GET_SERIAL_NUMBER = 0xD033;
static const uint16_t SEN5X_CMD_NOX_ALGORITHM_TUNING = 0x60E1;
static const uint16_t SEN5X_CMD_READ_MEASUREMENT = 0x03C4;
static const uint16_t SEN5X_CMD_RHT_ACCELERATION_MODE = 0x60F7;
static const uint16_t SEN5X_CMD_START_CLEANING_FAN = 0x5607;
static const uint16_t SEN5X_CMD_START_MEASUREMENTS = 0x0021;
static const uint16_t SEN5X_CMD_START_MEASUREMENTS_RHT_ONLY = 0x0037;
static const uint16_t SEN5X_CMD_STOP_MEASUREMENTS = 0x3f86;
static const uint16_t SEN5X_CMD_TEMPERATURE_COMPENSATION = 0x60B2;
static const uint16_t SEN5X_CMD_VOC_ALGORITHM_STATE = 0x6181;
static const uint16_t SEN5X_CMD_VOC_ALGORITHM_TUNING = 0x60D0;
 
static const int8_t SEN5X_INDEX_SCALE_FACTOR = 10;                            // used for VOC and NOx index values
static const int8_t SEN5X_MIN_INDEX_VALUE = 1 * SEN5X_INDEX_SCALE_FACTOR;     // must be adjusted by the scale factor
static const int16_t SEN5X_MAX_INDEX_VALUE = 500 * SEN5X_INDEX_SCALE_FACTOR;  // must be adjusted by the scale factor
 
static const LogString *type_to_string(Sen5xType type) {
  switch (type) {
    case Sen5xType::SEN50:
      return LOG_STR("SEN50");
    case Sen5xType::SEN54:
      return LOG_STR("SEN54");
    case Sen5xType::SEN55:
      return LOG_STR("SEN55");
    default:
      return LOG_STR("UNKNOWN");
  }
}
 
static const LogString *rht_accel_mode_to_string(RhtAccelerationMode mode) {
  switch (mode) {
    case LOW_ACCELERATION:
      return LOG_STR("LOW");
    case MEDIUM_ACCELERATION:
      return LOG_STR("MEDIUM");
    case HIGH_ACCELERATION:
      return LOG_STR("HIGH");
    default:
      return LOG_STR("UNKNOWN");
  }
}
 
void SEN5XComponent::setup() {
  // the sensor needs 1000 ms to enter the idle state
  this->set_timeout(1000, [this]() {
    // Check if measurement is ready before reading the value
    if (!this->write_command(SEN5X_CMD_GET_DATA_READY_STATUS)) {
      this->mark_failed(LOG_STR("Failed to write data ready status command"));
      return;
    }
    delay(20);  // per datasheet
 
    uint16_t raw_read_status;
    if (!this->read_data(raw_read_status)) {
      this->mark_failed(LOG_STR("Failed to read data ready status"));
      return;
    }
 
    uint32_t stop_measurement_delay = 0;
    // In order to query the device periodic measurement must be ceased
    if (raw_read_status) {
      ESP_LOGD(TAG, "Data is available; stopping periodic measurement");
      if (!this->write_command(SEN5X_CMD_STOP_MEASUREMENTS)) {
        this->mark_failed(LOG_STR("Failed to stop measurements"));
        return;
      }
      // According to the SEN5x datasheet the sensor will only respond to other commands after waiting 200 ms after
      // issuing the stop_periodic_measurement command
      stop_measurement_delay = 200;
    }
    this->set_timeout(stop_measurement_delay, [this]() {
      // note: serial number register is actually 32-bytes long but we grab only the first 16-bytes,
      // this appears to be all that Sensirion uses for serial numbers, this could change
      uint16_t raw_serial_number[8];
      if (!this->get_register(SEN5X_CMD_GET_SERIAL_NUMBER, raw_serial_number, 8, 20)) {
        this->mark_failed(LOG_STR("Unable to read serial ID"));
        return;
      }
      const char *serial_number = sensirion_convert_to_string_in_place(raw_serial_number, 8);
      snprintf(this->serial_number_, sizeof(this->serial_number_), "%s", serial_number);
      ESP_LOGV(TAG, "Serial number %s", this->serial_number_);
 
      uint16_t raw_product_name[16];
      Sen5xType detected_type = Sen5xType::UNKNOWN;
      if (this->get_register(SEN5X_CMD_GET_PRODUCT_NAME, raw_product_name, 16, 20)) {
        const char *product_name = sensirion_convert_to_string_in_place(raw_product_name, 16);
        if (strncmp(product_name, "SEN50", 5) == 0) {
          detected_type = Sen5xType::SEN50;
        } else if (strncmp(product_name, "SEN54", 5) == 0) {
          detected_type = Sen5xType::SEN54;
        } else if (strncmp(product_name, "SEN55", 5) == 0) {
          detected_type = Sen5xType::SEN55;
        }
      }
 
      if (this->model_override_.has_value()) {
        if (detected_type != this->model_override_.value()) {
          ESP_LOGW(TAG, "Detected %s, using %s", LOG_STR_ARG(type_to_string(detected_type)),
                   LOG_STR_ARG(type_to_string(this->model_override_.value())));
        }
        this->type_ = this->model_override_.value();
      } else if (detected_type == Sen5xType::UNKNOWN) {
        this->type_ = Sen5xType::UNKNOWN;
        this->mark_failed(LOG_STR("Unable to read product name"));
        return;
      } else {
        this->type_ = detected_type;
      }
 
      ESP_LOGD(TAG, "Type: %s", LOG_STR_ARG(type_to_string(this->type_)));
      if (this->humidity_sensor_ && this->type_ == Sen5xType::SEN50) {
        ESP_LOGE(TAG, "Relative humidity requires a SEN54 or SEN55");
        this->humidity_sensor_ = nullptr;  // mark as not used
      }
      if (this->temperature_sensor_ && this->type_ == Sen5xType::SEN50) {
        ESP_LOGE(TAG, "Temperature requires a SEN54 or SEN55");
        this->temperature_sensor_ = nullptr;  // mark as not used
      }
      if (this->voc_sensor_ && this->type_ == Sen5xType::SEN50) {
        ESP_LOGE(TAG, "VOC requires a SEN54 or SEN55");
        this->voc_sensor_ = nullptr;  // mark as not used
      }
      if (this->nox_sensor_ && this->type_ != Sen5xType::SEN55) {
        ESP_LOGE(TAG, "NOx requires a SEN55");
        this->nox_sensor_ = nullptr;  // mark as not used
      }
 
      if (!this->get_register(SEN5X_CMD_GET_FIRMWARE_VERSION, this->firmware_version_, 20)) {
        this->mark_failed(LOG_STR("Unable to read firmware version"));
        return;
      }
      this->firmware_version_ >>= 8;
      ESP_LOGV(TAG, "Firmware version %d", this->firmware_version_);
 
      if (this->voc_sensor_ && this->store_baseline_) {
        // Hash with serial number, serial numbers are unique, so multiple sensors can be used without conflict
        uint32_t hash = fnv1a_hash(this->serial_number_);
        this->pref_ = global_preferences->make_preference<uint16_t[4]>(hash, true);
        this->voc_baseline_time_ = App.get_loop_component_start_time();
        if (this->pref_.load(&this->voc_baseline_state_)) {
          if (!this->write_command(SEN5X_CMD_VOC_ALGORITHM_STATE, this->voc_baseline_state_, 4)) {
            ESP_LOGE(TAG, "VOC Baseline State write to sensor failed");
          } else {
            ESP_LOGV(TAG, "VOC Baseline State loaded");
            delay(20);
          }
        }
      }
      bool result;
      if (this->auto_cleaning_interval_.has_value()) {
        // override default value
        result = this->write_command(SEN5X_CMD_AUTO_CLEANING_INTERVAL, this->auto_cleaning_interval_.value());
      } else {
        result = this->write_command(SEN5X_CMD_AUTO_CLEANING_INTERVAL);
      }
      if (result) {
        delay(20);
        uint16_t secs[2];
        if (this->read_data(secs, 2)) {
          this->auto_cleaning_interval_ = secs[0] << 16 | secs[1];
        }
      }
      if (this->acceleration_mode_.has_value()) {
        result = this->write_command(SEN5X_CMD_RHT_ACCELERATION_MODE, this->acceleration_mode_.value());
      } else {
        result = this->write_command(SEN5X_CMD_RHT_ACCELERATION_MODE);
      }
      if (!result) {
        this->mark_failed(LOG_STR("Failed to set rh/t acceleration mode"));
        return;
      }
      delay(20);
      if (!this->acceleration_mode_.has_value()) {
        uint16_t mode;
        if (this->read_data(mode)) {
          this->acceleration_mode_ = RhtAccelerationMode(mode);
        } else {
          ESP_LOGE(TAG, "Failed to read RHT Acceleration mode");
        }
      }
      if (this->voc_tuning_params_.has_value()) {
        this->write_tuning_parameters_(SEN5X_CMD_VOC_ALGORITHM_TUNING, this->voc_tuning_params_.value());
        delay(20);
      }
      if (this->nox_tuning_params_.has_value()) {
        this->write_tuning_parameters_(SEN5X_CMD_NOX_ALGORITHM_TUNING, this->nox_tuning_params_.value());
        delay(20);
      }
 
      if (this->temperature_compensation_.has_value()) {
        this->write_temperature_compensation_(this->temperature_compensation_.value());
        delay(20);
      }
 
      // Finally start sensor measurements
      auto cmd = SEN5X_CMD_START_MEASUREMENTS_RHT_ONLY;
      if (this->pm_1_0_sensor_ || this->pm_2_5_sensor_ || this->pm_4_0_sensor_ || this->pm_10_0_sensor_) {
        // if any of the gas sensors are active we need a full measurement
        cmd = SEN5X_CMD_START_MEASUREMENTS;
      }
 
      if (!this->write_command(cmd)) {
        this->mark_failed(LOG_STR("Error starting continuous measurements"));
        return;
      }
      this->initialized_ = true;
    });
  });
}
 
void SEN5XComponent::dump_config() {
  ESP_LOGCONFIG(TAG, "SEN5X:");
  LOG_I2C_DEVICE(this);
  ESP_LOGCONFIG(TAG,
                "  Type: %s%s\n"
                "  Firmware version: %d\n"
                "  Serial number: %s",
                LOG_STR_ARG(type_to_string(this->type_)),
                this->model_override_.has_value() ? LOG_STR_LITERAL(" (overridden)") : LOG_STR_LITERAL(""),
                this->firmware_version_, this->serial_number_);
  if (this->auto_cleaning_interval_.has_value()) {
    ESP_LOGCONFIG(TAG, "  Auto cleaning interval: %" PRId32 "s", this->auto_cleaning_interval_.value());
  }
  if (this->acceleration_mode_.has_value()) {
    ESP_LOGCONFIG(TAG, "  RH/T acceleration mode: %s",
                  LOG_STR_ARG(rht_accel_mode_to_string(this->acceleration_mode_.value())));
  }
  if (this->voc_sensor_) {
    char hex_buf[5 * 4];
    format_hex_pretty_to(hex_buf, this->voc_baseline_state_, 4, 0);
    ESP_LOGCONFIG(TAG,
                  "  Store Baseline: %s\n"
                  "    State: %s\n",
                  TRUEFALSE(this->store_baseline_), hex_buf);
  }
  LOG_UPDATE_INTERVAL(this);
  LOG_SENSOR("  ", "PM  1.0", this->pm_1_0_sensor_);
  LOG_SENSOR("  ", "PM  2.5", this->pm_2_5_sensor_);
  LOG_SENSOR("  ", "PM  4.0", this->pm_4_0_sensor_);
  LOG_SENSOR("  ", "PM 10.0", this->pm_10_0_sensor_);
  LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
  LOG_SENSOR("  ", "Humidity", this->humidity_sensor_);
  LOG_SENSOR("  ", "VOC", this->voc_sensor_);  // SEN54 and SEN55 only
  LOG_SENSOR("  ", "NOx", this->nox_sensor_);  // SEN55 only
}
 
void SEN5XComponent::update() {
  if (!this->initialized_) {
    return;
  }
 
  if (!this->write_command(SEN5X_CMD_READ_MEASUREMENT)) {
    this->status_set_warning();
    ESP_LOGD(TAG, "Write error: read measurement (%d)", this->last_error_);
    return;
  }
  this->set_timeout(20, [this]() {
    uint16_t measurements[8];
 
    if (!this->read_data(measurements, 8)) {
      this->status_set_warning();
      ESP_LOGD(TAG, "Read data error (%d)", this->last_error_);
      return;
    }
 
    ESP_LOGVV(TAG, "pm_1_0 = 0x%.4x", measurements[0]);
    float pm_1_0 = measurements[0] == UINT16_MAX ? NAN : measurements[0] / 10.0f;
 
    ESP_LOGVV(TAG, "pm_2_5 = 0x%.4x", measurements[1]);
    float pm_2_5 = measurements[1] == UINT16_MAX ? NAN : measurements[1] / 10.0f;
 
    ESP_LOGVV(TAG, "pm_4_0 = 0x%.4x", measurements[2]);
    float pm_4_0 = measurements[2] == UINT16_MAX ? NAN : measurements[2] / 10.0f;
 
    ESP_LOGVV(TAG, "pm_10_0 = 0x%.4x", measurements[3]);
    float pm_10_0 = measurements[3] == UINT16_MAX ? NAN : measurements[3] / 10.0f;
 
    ESP_LOGVV(TAG, "humidity = 0x%.4x", measurements[4]);
    float humidity = measurements[4] == INT16_MAX ? NAN : static_cast<int16_t>(measurements[4]) / 100.0f;
 
    ESP_LOGVV(TAG, "temperature = 0x%.4x", measurements[5]);
    float temperature = measurements[5] == INT16_MAX ? NAN : static_cast<int16_t>(measurements[5]) / 200.0f;
 
    ESP_LOGVV(TAG, "voc = 0x%.4x", measurements[6]);
    int16_t voc_idx = static_cast<int16_t>(measurements[6]);
    float voc = (voc_idx < SEN5X_MIN_INDEX_VALUE || voc_idx > SEN5X_MAX_INDEX_VALUE)
                    ? NAN
                    : static_cast<float>(voc_idx) / 10.0f;
 
    ESP_LOGVV(TAG, "nox = 0x%.4x", measurements[7]);
    int16_t nox_idx = static_cast<int16_t>(measurements[7]);
    float nox = (nox_idx < SEN5X_MIN_INDEX_VALUE || nox_idx > SEN5X_MAX_INDEX_VALUE)
                    ? NAN
                    : static_cast<float>(nox_idx) / 10.0f;
 
    if (this->pm_1_0_sensor_ != nullptr) {
      this->pm_1_0_sensor_->publish_state(pm_1_0);
    }
    if (this->pm_2_5_sensor_ != nullptr) {
      this->pm_2_5_sensor_->publish_state(pm_2_5);
    }
    if (this->pm_4_0_sensor_ != nullptr) {
      this->pm_4_0_sensor_->publish_state(pm_4_0);
    }
    if (this->pm_10_0_sensor_ != nullptr) {
      this->pm_10_0_sensor_->publish_state(pm_10_0);
    }
    if (this->temperature_sensor_ != nullptr) {
      this->temperature_sensor_->publish_state(temperature);
    }
    if (this->humidity_sensor_ != nullptr) {
      this->humidity_sensor_->publish_state(humidity);
    }
    if (this->voc_sensor_ != nullptr) {
      this->voc_sensor_->publish_state(voc);
    }
    if (this->nox_sensor_ != nullptr) {
      this->nox_sensor_->publish_state(nox);
    }
 
    if (!this->voc_sensor_ || !this->store_baseline_ ||
        (App.get_loop_component_start_time() - this->voc_baseline_time_) < SHORTEST_BASELINE_STORE_INTERVAL) {
      this->status_clear_warning();
    } else {
      this->voc_baseline_time_ = App.get_loop_component_start_time();
      if (!this->write_command(SEN5X_CMD_VOC_ALGORITHM_STATE)) {
        this->status_set_warning();
        ESP_LOGW(TAG, ESP_LOG_MSG_COMM_FAIL);
      } else {
        this->set_timeout(20, [this]() {
          if (!this->read_data(this->voc_baseline_state_, 4)) {
            this->status_set_warning();
            ESP_LOGW(TAG, ESP_LOG_MSG_COMM_FAIL);
          } else {
            if (this->pref_.save(&this->voc_baseline_state_)) {
              ESP_LOGD(TAG, "VOC Baseline State saved");
            }
            this->status_clear_warning();
          }
        });
      }
    }
  });
}
 
bool SEN5XComponent::write_tuning_parameters_(uint16_t i2c_command, const GasTuning &tuning) {
  uint16_t params[6];
  params[0] = tuning.index_offset;
  params[1] = tuning.learning_time_offset_hours;
  params[2] = tuning.learning_time_gain_hours;
  params[3] = tuning.gating_max_duration_minutes;
  params[4] = tuning.std_initial;
  params[5] = tuning.gain_factor;
  auto result = write_command(i2c_command, params, 6);
  if (!result) {
    ESP_LOGE(TAG, "Set tuning parameters failed (command=%0xX, err=%d)", i2c_command, this->last_error_);
  }
  return result;
}
 
bool SEN5XComponent::write_temperature_compensation_(const TemperatureCompensation &compensation) {
  uint16_t params[3];
  params[0] = compensation.offset;
  params[1] = compensation.normalized_offset_slope;
  params[2] = compensation.time_constant;
  if (!write_command(SEN5X_CMD_TEMPERATURE_COMPENSATION, params, 3)) {
    ESP_LOGE(TAG, "Set temperature_compensation failed (%d)", this->last_error_);
    return false;
  }
  return true;
}
 
bool SEN5XComponent::start_fan_cleaning() {
  if (!write_command(SEN5X_CMD_START_CLEANING_FAN)) {
    this->status_set_warning();
    ESP_LOGE(TAG, "Start fan cleaning failed (%d)", this->last_error_);
    return false;
  } else {
    ESP_LOGD(TAG, "Fan auto clean started");
  }
  return true;
}
 
}  // namespace esphome::sen5x