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SEN6x Series Environmental Sensor

The sen6x sensor platform allows you to use your Sensirion SEN62, SEN63C, SEN65, SEN66, SEN68 and SEN69C Environmental sensor (datasheet) sensors with ESPHome.

The I²C Bus is required to be set up in your configuration for this sensor to work.

SEN6x Environmental Sensor

SensorPMRH/TVOCNOxCO₂HCHO
SEN62✓✓
SEN63C✓✓✓
SEN65✓✓✓✓
SEN66✓✓✓✓✓
SEN68✓✓✓✓✓
SEN69C✓✓✓✓✓✓
# Example configuration entry
sensor:
  - platform: sen6x
    type: SEN69C
    pm_1_0:
      name: PM <1µm Weight concentration
    pm_2_5:
      name: PM <2.5µm Weight concentration
    pm_4_0:
      name: PM <4µm Weight concentration
    pm_10_0:
      name: PM <10µm Weight concentration
    temperature:
      name: Temperature
    humidity:
      name: Humidity
    voc_index:
      name: VOC Index
    nox_index:
      name: NOx Index
    co2:
      name: Carbon Dioxide
    formaldehyde:
      name: Formaldehyde

NOTE

The voc and nox keys were renamed to voc_index and nox_index, since these sensors report Sensirion’s unitless Gas Index rather than a concentration. The old keys still work but are deprecated and will be removed in ESPHome 2027.2.0.

Configuration variables

Section titled “Configuration variables”

  • type (Optional): The type of sensor. If not specified, sensor type will be auto-detected. If specified, the value will override auto-detection. In case of mismatch, a warning will be provided in the log.

    • SEN62
    • SEN63C
    • SEN65
    • SEN66
    • SEN68
    • SEN69C

  • pm_1_0 (Optional): The information for the Weight Concentration sensor for fine particles up to 1μm. Readings in µg/m³.

  • pm_2_5 (Optional): The information for the Weight Concentration sensor for fine particles up to 2.5μm. Readings in µg/m³.

  • pm_4_0 (Optional): The information for the Weight Concentration sensor for coarse particles up to 4μm. Readings in µg/m³.

  • pm_10_0 (Optional): The information for the Weight Concentration sensor for coarse particles up to 10μm. Readings in µg/m³.

  • temperature (Optional): Temperature.

  • humidity (Optional): Relative Humidity.

  • voc_index (Optional): VOC Index. Note: only available with SEN65, SEN66, SEN68 or SEN69C. The sensor will be ignored on unsupported models.

    • algorithm_tuning (Optional): The VOC algorithm can be customized by tuning 6 different parameters. For more details see the SEN6x datasheet.

      • index_offset (Optional): VOC index representing typical (average) conditions. Allowed values are in range 1..250. The default value is 100.
      • learning_time_offset_hours (Optional): Time constant to estimate the VOC algorithm offset from the history in hours. Past events will be forgotten after about twice the learning time. Allowed values are in range 1..1000. The default value is 12 hours.
      • learning_time_gain_hours (Optional): Time constant to estimate the VOC algorithm gain from the history in hours. Past events will be forgotten after about twice the learning time. Allowed values are in range 1..1000. The default value is 12 hours.
      • gating_max_duration_minutes (Optional): Maximum duration of gating in minutes (freeze of estimator during high VOC index signal). Zero disables the gating. Allowed values are in range 0..3000. The default value is 180 minutes.
      • std_initial (Optional): Initial estimate for standard deviation. Lower value boosts events during initial learning period, but may result in larger device-to-device variations. Allowed values are in range 10..5000. The default value is 50.
      • gain_factor (Optional): Gain factor to amplify or to attenuate the VOC index output. Allowed values are in range 1..1000. The default value is 230.

    • All other options from Sensor.

  • nox_index (Optional): NOx Index. Note: only available with SEN65, SEN66, SEN68 or SEN69C. The sensor will be ignored on unsupported models.

    • algorithm_tuning (Optional): The NOx algorithm can be customized by tuning 5 different parameters. For more details see the SEN6x datasheet. Unlike VOC, the NOx algorithm has no configurable std_initial; the device requires it to be 50 and ESPHome always sends that value.

      • index_offset (Optional): NOx index representing typical (average) conditions. Allowed values are in range 1..250. The default value is 1.
      • learning_time_offset_hours (Optional): Time constant to estimate the NOx algorithm offset from the history in hours. Past events will be forgotten after about twice the learning time. Allowed values are in range 1..1000. The default value is 12 hours.
      • learning_time_gain_hours (Optional): Time constant to estimate the NOx algorithm gain from the history in hours. Past events will be forgotten after about twice the learning time. Allowed values are in range 1..1000. The default value is 12 hours.
      • gating_max_duration_minutes (Optional): Maximum duration of gating in minutes (freeze of estimator during high NOx index signal). Zero disables the gating. Allowed values are in range 0..3000. The default value is 720 minutes.
      • gain_factor (Optional): Gain factor to amplify or to attenuate the NOx index output. Allowed values are in range 1..1000. The default value is 230.

    • All other options from Sensor.

  • co2 (Optional): The carbon dioxide concentration in ppm. Note: only available with SEN63C, SEN66 or SEN69C. The sensor will be ignored on unsupported models.

  • formaldehyde (Optional): The Formaldehyde (HCHO) concentration in ppb. Note: only available with SEN68 or SEN69C. The sensor will be ignored on unsupported models.

  • address (Optional, int): Manually specify the I²C address of the sensor. Defaults to 0x6B.

  • update_interval (Optional, Time): The interval to check the sensor. Defaults to 60s.

NOTE

The sensor needs about a minute “warm-up”. The VOC and NOx gas index algorithm needs a number of samples before the values stabilize.

Wiring

Section titled “Wiring”

The sensor has a JST GHR-06V-S 6 pin type connector, with a 1.25mm pitch. The cable needs this connector:

JST GHR-06V-S 6-pin connector

Pins 2 and 5 (GND) and pins 1 and 6 (VDD) are connected internally.

For better stability, the SDA and SCL lines require suitable pull-up resistors.

See Also

Section titled “See Also”