API Documentation

SEN69C

Sen69cDevice

The class Sen69cDeviceBase implements the low level interface of the sensor. The class Sen69cDevice extends the Sen69cDeviceBase. It provides additional functions to ease the use of the sensor.

class sensirion_i2c_sen69c.device.Sen69cDeviceBase(channel)

Low level API implementation of SEN69C

__init__(channel)

property channel

get_voc_algorithm_tuning_parameters()

Gets the parameters to customize the VOC algorithm.

Return index_offset:

VOC index representing typical (average) conditions.

Return learning_time_offset_hours:

Time constant to estimate the VOC algorithm offset from the history in hours. Past events will be forgotten after about twice the learning time.

Return learning_time_gain_hours:

Time constant to estimate the VOC algorithm gain from the history in hours. Past events will be forgotten after about twice the learning time.

Return gating_max_duration_minutes:

Maximum duration of gating in minutes (freeze of estimator during high VOC index signal). Zero disables the gating.

Return std_initial:

Initial estimate for standard deviation. Lower value boosts events during initial learning period, but may result in larger device-to-device variations.

Return gain_factor:

Gain factor to amplify or to attenuate the VOC index output.

Note

This command is only available in idle mode.

set_voc_algorithm_tuning_parameters(index_offset, learning_time_offset_hours, learning_time_gain_hours, gating_max_duration_minutes, std_initial, gain_factor)

Sets the parameters to customize the VOC algorithm. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

Parameters:

• index_offset – VOC index representing typical (average) conditions. Allowed values are in range 1..250. The default value is 100.

• learning_time_offset_hours – 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 – 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 – Maximum duration of gating in minutes (freeze of estimator during high VOC index signal). Set to zero to disable the gating. Allowed values are in range 0..3000. The default value is 180 minutes

• std_initial – 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 – Gain factor to amplify or to attenuate the VOC index output. Allowed values are in range 1..1000. The default value is 230.

Note

This command is available only in idle mode. In measure mode, this command has no effect. In addition, it has no effect if at least one parameter is outside the specified range.

Example:

sensor.set_voc_algorithm_tuning_parameters(100, 12, 12, 180, 50, 230)

get_voc_algorithm_state()

Gets the current VOC algorithm state. Allows to backup and restore the VOC algorithm state to resume operation after a power cycle or device reset, skipping initial learning phase. By default, the VOC Engine is reset and the algorithm state is retained if a measurement is stopped and started again. If the VOC algorithm state shall be reset, a device reset or a power cycle can be executed.

Return state:

Current VOC algorithm state.

Note

This command can be used either in measure mode or in idle mode (which will then return the state at the time when the measurement was stopped). In measure mode, the state can be read each measure interval to always have the latest state available, even in case of a sudden power loss.

set_voc_algorithm_state(state)

Sets the VOC algorithm state previously received with “Get VOC Algorithm State” command. Allows restoration of the VOC algorithm state to resume operation after a power cycle or device reset, skipping initial learning phase. By default, the VOC Engine is reset, and the algorithm state is retained if a measurement is stopped and started again. If the VOC algorithm state shall be reset, a device reset, or a power cycle can be executed.

Parameters:

state – VOC algorithm state to restore.

Note

This command is only available in idle mode and the state will be applied only once when starting the next measurement. In measure mode, this command has no effect.

get_nox_algorithm_tuning_parameters()

Gets the parameters to customize the NOx algorithm.

Return index_offset:

NOx index representing typical (average) conditions.

Return learning_time_offset_hours:

Time constant to estimate the NOx algorithm offset from the history in hours. Past events will be forgotten after about twice the learning time.

Return learning_time_gain_hours:

The time constant to estimate the NOx algorithm gain from the history has no impact for NOx. This parameter is still in place for consistency reasons with the VOC tuning parameters command.

Return gating_max_duration_minutes:

Maximum duration of gating in minutes (freeze of estimator during high NOx index signal). Zero disables the gating.

Return std_initial:

The initial estimate for standard deviation has no impact for NOx. This parameter is still in place for consistency reasons with the VOC tuning parameters command.

Return gain_factor:

Gain factor to amplify or to attenuate the NOx index output.

Note

This command is available only in idle mode.

set_nox_algorithm_tuning_parameters(index_offset, learning_time_offset_hours, learning_time_gain_hours, gating_max_duration_minutes, std_initial, gain_factor)

Sets the parameters to customize the NOx algorithm. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

Parameters:

• index_offset – NOx index representing typical (average) conditions. Allowed values are in range 1..250. The default value is 1.

• learning_time_offset_hours – 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 – The time constant to estimate the NOx algorithm gain from the history has no impact for NOx. This parameter is still in place for consistency reasons with the VOC tuning parameters command. This parameter must always be set to 12 hours.

• gating_max_duration_minutes – Maximum duration of gating in minutes (freeze of estimator during high NOx index signal). Set to zero to disable the gating. Allowed values are in range 0..3000. The default value is 720 minutes.

• std_initial – The initial estimate for standard deviation parameter has no impact for NOx. This parameter is still in place for consistency reasons with the VOC tuning parameters command. This parameter must always be set to 50.

• gain_factor – Gain factor to amplify or to attenuate the NOx index output. Allowed values are in range 1..1000. The default value is 230.

Note

This command is available only in idle mode. In measure mode, this command has no effect. In addition, it has no effect if at least one parameter is outside the specified range.

Example:

sensor.set_nox_algorithm_tuning_parameters(1, 12, 12, 720, 50, 230)

perform_forced_co2_recalibration(target_co2_concentration)

Execute the forced recalibration (FRC) of the CO₂. See the datasheet of the SCD4x sensor for details how the forced recalibration shall be used.

Parameters:

target_co2_concentration – Target CO₂ concentration [ppm] of the test setup.

Return correction:

Correction value as received from the SCD [ppm CO₂]. FRC correction [ppm CO₂] is calculated as follows: FRC = return_value - 0x8000 If the recalibration has failed this returned value is 0xFFFF.

Note

After power-on wait at least 1000 ms and after stopping a measurement 600 ms before sending this command. This command is not available in measure mode. The recalibration procedure will take about 500 ms to complete, during which time no other functions can be executed. This configuration is persistent, i.e. the parameters will be retained during a device reset or power cycle.

perform_co2_sensor_factory_reset()

This command resets all CO₂ sensor configuration settings stored in the EEPROM and erases the FRC and ASC algorithm history of the CO₂ sensor. The configuration settings are CO₂ sensor temperature offset (cannot be modified over I2C interface), sensor altitude and the ASC enabled/disabled parameters which are by default stored in the volatile memory (RAM). This command is only available in idle mode.

get_co2_sensor_automatic_self_calibration()

The CO₂ sensor supports automatic self calibration (ASC) for long-term stability of the CO₂ output. This feature can be enabled or disabled. By default it is enabled.

Return padding:

Padding byte, always 0x00.

Return status:

Is set true (0x01) if the automatic self calibration is enabled or false (0x00) if the automatic self calibration is disabled.

Note

This command is only available in idle mode. This configuration is persistent, i.e. the status will be retained during a device reset or power cycle.

set_co2_sensor_automatic_self_calibration(status)

Sets the status of the CO₂ sensor automatic self-calibration (ASC). The CO₂ sensor supports automatic self calibration (ASC) for long-term stability of the CO₂ output. This feature can be enabled or disabled. By default it is enabled.

Parameters:

status – Set to true (0x0001) to enable or false (0x0000) to disable the automatic CO₂ measurement self calibration feature. High byte of uint16 is padding and always 0x00.

Note

This command is only available in idle mode. This configuration is persistent, i.e. the status will be retained during a device reset or power cycle.

Example:

sensor.set_co2_sensor_automatic_self_calibration(0)

get_ambient_pressure()

Gets the ambient pressure value. The ambient pressure can be used for pressure compensation in the CO₂ sensor.

Return ambient_pressure:

Currently used ambient pressure [hPa] for pressure compensation.

Note

This command can be used in any state of the device, i.e. both in idle mode and in measure mode.

set_ambient_pressure(ambient_pressure)

The ambient pressure can be used for pressure compensation in the CO₂ sensor. Setting an ambient pressure overrides any pressure compensation based on a previously set sensor altitude. Use of this command is recommended for applications experiencing significant ambient pressure changes to ensure CO₂ sensor accuracy. Valid input values are between 700 to 1’200 hPa. The default value is 1013 hPa. This configuration is volatile, i.e. the parameter will be reverted to its default value after a device restart.

Parameters:

ambient_pressure – Ambient pressure [hPa] to be used for pressure compensation.

Note

This command can be used in any state of the device, i.e. both in idle mode and in measure mode.

Example:

sensor.set_ambient_pressure(1013)

get_sensor_altitude()

Gets the current sensor altitude. The sensor altitude can be used for pressure compensation in the CO₂ sensor.

Return altitude:

Current sensor altitude [m].

Note

This command is only available in idle mode.

set_sensor_altitude(altitude)

The sensor altitude can be used for pressure compensation in the CO₂ sensor. The default sensor altitude value is set to 0 meters above sea level. Valid input values are between 0 and 3000m. This configuration is volatile, i.e. the parameter will be reverted to its default value after a device reset.

Parameters:

altitude – Sensor altitude [m], valid input between 0 and 3000m.

Example:

sensor.set_sensor_altitude(0)

start_continuous_measurement()

Starts a continuous measurement. After starting the measurement, it takes some time (~1.1s) until the first measurement results are available. You could poll with the command “Get Data Ready” to check when the results are ready to read. This command is only available in idle mode. If the device is already in any measure mode, this command has no effect.

stop_measurement()

Stops the measurement and returns to idle mode. After sending this command, wait at least 1000 ms before starting a new measurement. If the device is already in idle mode, this command has no effect.

get_data_ready()

This command can be used to check if new measurement results are ready to read. The data ready flag is automatically reset after reading the measurement values.

Return padding:

Padding byte, always 0x00.

Return data_ready:

True (0x01) if data is ready, False (0x00) if not. When no measurement is running, False will be returned.

read_number_concentration_values_as_integers()

Returns the measured number concentration values. The command 0x0202 “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16).

Return number_concentration_pm0p5:

Value is scaled with factor 10: PM0.5 [particles/cm³] = value / 10. Note: If this value is unknown, 0xFFFF is returned.

Return number_concentration_pm1p0:

Value is scaled with factor 10: PM1.0 [particles/cm³] = value / 10. Note: If this value is unknown, 0xFFFF is returned.

Return number_concentration_pm2p5:

Value is scaled with factor 10: PM2.5 [particles/cm³] = value / 10. Note: If this value is unknown, 0xFFFF is returned.

Return number_concentration_pm4p0:

Value is scaled with factor 10: PM4.0 [particles/cm³] = value / 10. Note: If this value is unknown, 0xFFFF is returned.

Return number_concentration_pm10p0:

Value is scaled with factor 10: PM10.0 [particles/cm³] = value / 10. Note: If this value is unknown, 0xFFFF is returned.

set_temperature_offset_parameters(offset, slope, time_constant, slot)

This command allows to compensate temperature effects of the design-in at customer side by applying custom temperature offsets to the ambient temperature.

The compensated ambient temperature is calculated as follows:

• T_Ambient_Compensated = T_Ambient + (slope * T_Ambient) + offset

Where “slope” and “offset” are the values set with this command, smoothed with the specified time constant. All temperatures (“T_Ambient_Compensated”, “T_Ambient” and “offset”) are represented in °C. There are 5 temperature offset slots available that all contribute additively to “T_Ambient_Compensated”. The default values for the temperature offset parameters are all zero, meaning that “T_Ambient_Compensated” is equal to “T_Ambient” by default. The parameters can be changed in any state of the device, i.e. both in idle mode and in measure mode.

Parameters:

• offset – Constant temperature offset scaled with factor 200 (T [°C] = value / 200).

• slope – Normalized temperature offset slope scaled with factor 10000 (applied factor = value / 10000).

• time_constant – The time constant determines how fast the new slope and offset will be applied. After the specified value in seconds, 63% of the new slope and offset are applied. A time constant of zero means the new values will be applied immediately (within the next measure interval of 1 second).

• slot – The temperature offset slot to be modified. Valid values are 0 .. 4. If the value is outside this range, the parameters will not be applied.

Note

This configuration is volatile, i.e. the parameters will be reverted to their default value of zero after a device reset.

Example:

sensor.set_temperature_offset_parameters(1, 10, 1, 0)

set_temperature_acceleration_parameters(k, p, t1, t2)

This command allows to set custom temperature acceleration parameters of the RH/T engine. It overwrites the default temperature acceleration parameters of the RH/T engine with custom values. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

Parameters:

• k – Filter constant K scaled with factor 10 (K = value / 10).

• p – Filter constant P scaled with factor 10 (P = value / 10).

• t1 – Time constant T1 scaled with factor 10 (T1 [s] = value / 10).

• t2 – Time constant T2 scaled with factor 10 (T2 [s] = value / 10).

Note

The command is only available in idle mode.

Example:

sensor.set_temperature_acceleration_parameters(1, 1, 1, 1)

get_product_name()

Gets the product name from the device.

Return product_name:

Null-terminated ASCII string containing the product name. Up to 32 characters can be read from the device.

get_serial_number()

Gets the serial number from the device.

Return serial_number:

Null-terminated ASCII string containing the serial number. Up to 32 characters can be read from the device.

read_device_status()

Reads the current device status. Use this command to get detailed information about the device status. The device status is encoded in flags. Each device status flag represents a single bit in a 32-bit integer value. If more than one error is present, the device status register value is the sum of the corresponding flag values. For details about the available flags, refer to the device status flags documentation in the data sheet.

Return device_status:

Device status (32 flags as an integer value). For details, please refer to the device status flags documentation in the datasheet.

Note

The status flags of type “Error” are sticky, i.e. they are not cleared automatically even if the error condition no longer exists. So they can only be cleared manually with the command “Read And Clear Device Status” or with a device reset. All other flags are not sticky, i.e. they are cleared automatically if the trigger condition disappears.

read_and_clear_device_status()

Reads the current device status (like command 0xD206 “Read Device Status”) and afterwards clears all flags.

Return device_status:

Device status (32 flags as an integer value) before clearing it. For details, please refer to the device status flags documentation.

get_version()

Gets the version information for the firmware.

Return firmware_major:

Firmware major version number.

Return firmware_minor:

Firmware minor version number.

device_reset()

Executes a reset on the device. This has the same effect as a power cycle.

start_fan_cleaning()

This command triggers fan cleaning. The fan is set to the maximum speed for 10 seconds and then automatically stopped. Wait at least 10s after this command before starting a measurement.

Note

This command is only available in idle mode.

activate_sht_heater()

Activate the heater feature of the SHT4x sensor. This command allows to use the inbuilt heater in SHT sensor to decontaminate and reverse creep at high humidity. This command activates the SHT sensor heater with 200mW for 1s. The SHT heater measurement done just before deactivation can be read using the command “Get SHT Heater Measurements” after the duration of the heating feature as specified in the SHT4x datasheet. Wait at least 20s after this command before starting a measurement to get coherent temperature values (heating consequence to disappear).

Note

This command is only available in idle mode.

get_sht_heater_measurements()

Get the measurement values when the SHT sensor heating is finished.

Return sht_relative_humidity:

If the sht heating is completed, this value indicates the scaled relative humidity of the SHT4x sensor. Value is scaled with factor 100: RH [%] = value / 100 Note: If this value is not available, 0x7FFF is returned.

Return sht_temperature:

If the sht heating is completed, this value indicates the scaled temperature of the SHT4x sensor. Value is scaled with factor 200: T [°C] = value / 200 Note: If this value is not available, 0x7FFF is returned.

Note

This command must be used after the “Activate SHT Heater” command. The get sht heater measurements command can be queried every 0.05s to get the measurements. This command is only available in idle mode.

read_measured_values_as_integers()

Returns the measured values. The command “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16, 0x7FFF for int16).

Return mass_concentration_pm1p0:

Value is scaled with factor 10: PM1.0 [µg/m³] = value / 10 Note: If this value is unknown, 0xFFFF is returned.

Return mass_concentration_pm2p5:

Value is scaled with factor 10: PM2.5 [µg/m³] = value / 10 Note: If this value is unknown, 0xFFFF is returned.

Return mass_concentration_pm4p0:

Value is scaled with factor 10: PM4.0 [µg/m³] = value / 10 Note: If this value is unknown, 0xFFFF is returned.

Return mass_concentration_pm10p0:

Value is scaled with factor 10: PM10.0 [µg/m³] = value / 10 Note: If this value is unknown, 0xFFFF is returned.

Return ambient_humidity:

Value is scaled with factor 100: RH [%] = value / 100 Note: If this value is unknown, 0x7FFF is returned.

Return ambient_temperature:

Value is scaled with factor 200: T [°C] = value / 200 Note: If this value is unknown, 0x7FFF is returned.

Return voc_index:

Value is scaled with factor 10: VOC Index = value / 10 Note: If this value is unknown, 0x7FFF is returned.

Return nox_index:

Value is scaled with factor 10: NOx Index = value / 10 Note: If this value is unknown, 0x7FFF is returned. During the first 10..11 seconds after power-on or device reset, this value will be 0x7FFF as well.

Return hcho:

Value is scaled with a factor of 10: HCHO [ppb] = value / 10 Note: If this value is unknown, 0xFFFF is returned. During the first 60 seconds after the first measurement start after power-on or device reset, this value will be 0xFFFF as well.

Return co2:

CO₂ concentration [ppm]. Note: If this value is unknown, 0x7FFF is returned. During the first 22..24 seconds starting a measurement, this value will be 0x7FFF.

read_measured_raw_values()

Returns the measured raw values. The command “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16, 0x7FFF for int16).

Return raw_humidity:

Value is scaled with factor 100: RH [%] = value / 100 Note: If this value is unknown, 0x7FFF is returned.

Return raw_temperature:

Value is scaled with factor 200: T [°C] = value / 200 Note: If this value is unknown, 0x7FFF is returned.

Return raw_voc:

Raw measured VOC ticks without scale factor. Note: If this value is unknown, 0xFFFF is returned.

Return raw_nox:

Raw measured NOx ticks without scale factor. Note: If this value is unknown, 0xFFFF is returned. During the first 10..11 seconds after power-on or device reset, this value will be 0xFFFF as well.

class sensirion_i2c_sen69c.device.Sen69cDevice(channel)

Driver class implementation of SEN69C

sen69c

Access to base class

__init__(channel)

read_measured_values()

Read measured values and apply scaling as defined in datasheet.

Return mass_concentration_pm1p0:

Mass concentration in μg/m³ for particles smaller than 1.0 μm.

Return mass_concentration_pm2p5:

Mass concentration in μg/m³ for particles smaller than 2.5 μm.

Return mass_concentration_pm4p0:

Mass concentration in μg/m³ for particles smaller than 4.0 μm.

Return mass_concentration_pm10p0:

Mass concentration in μg/m³ for particles smaller than 10.0 μm.

Return humidity:

Measured humidity in %RH.

Return temperature:

Measured temperature in degrees Celsius.

Return voc_index:

VOC Index

Return nox_index:

NOx Index

Return hcho:

Formaldehyde concentration in ppb.

Return co2:

CO2 concentration in ppm.

read_number_concentration_values()

Read measured number concentration values and apply scaling as defined in datasheet.

Return number_concentration_pm0p5:

Number concentration in particles/cm³ for particles smaller than 0.5 μm.

Return number_concentration_pm1p0:

Number concentration in particles/cm³ for particles smaller than 1.0 μm.

Return number_concentration_pm2p5:

Number concentration in particles/cm³ for particles smaller than 2.5 μm.

Return number_concentration_pm4p0:

Number concentration in particles/cm³ for particles smaller than 4.0 μm.

Return number_concentration_pm10p0:

Number concentration in particles/cm³ for particles smaller than 10.0 μm.

Commands

The transfer classes specify the data that is transferred between host and sensor. The generated transfer classes are used by the driver class and not intended for direct use.

class sensirion_i2c_sen69c.commands.DeviceStatus(int_value: int = 0, **kwargs)

reserved1 = (0, 4)

fan_error = (4, 1)

reserved2 = (5, 1)

rht_error = (6, 1)

gas_error = (7, 1)

reserved3 = (8, 1)

co2_2_error = (9, 1)

hcho_error = (10, 1)

pm_error = (11, 1)

co2_1_error = (12, 1)

reserved4 = (13, 8)

fan_speed_warning = (21, 1)

reserved5 = (22, 10)

class sensirion_i2c_sen69c.commands.GetVocAlgorithmTuningParameters

Gets the parameters to customize the VOC algorithm.

CMD_ID = 24784

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetVocAlgorithmTuningParameters(index_offset, learning_time_offset_hours, learning_time_gain_hours, gating_max_duration_minutes, std_initial, gain_factor)

Sets the parameters to customize the VOC algorithm. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

CMD_ID = 24784

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetVocAlgorithmState

Gets the current VOC algorithm state. Allows to backup and restore the VOC algorithm state to resume operation after a power cycle or device reset, skipping initial learning phase. By default, the VOC Engine is reset and the algorithm state is retained if a measurement is stopped and started again. If the VOC algorithm state shall be reset, a device reset or a power cycle can be executed.

CMD_ID = 24961

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetVocAlgorithmState(state)

Sets the VOC algorithm state previously received with “Get VOC Algorithm State” command. Allows restoration of the VOC algorithm state to resume operation after a power cycle or device reset, skipping initial learning phase. By default, the VOC Engine is reset, and the algorithm state is retained if a measurement is stopped and started again. If the VOC algorithm state shall be reset, a device reset, or a power cycle can be executed.

CMD_ID = 24961

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetNoxAlgorithmTuningParameters

Gets the parameters to customize the NOx algorithm.

CMD_ID = 24801

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetNoxAlgorithmTuningParameters(index_offset, learning_time_offset_hours, learning_time_gain_hours, gating_max_duration_minutes, std_initial, gain_factor)

Sets the parameters to customize the NOx algorithm. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

CMD_ID = 24801

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.PerformForcedCo2Recalibration(target_co2_concentration)

Execute the forced recalibration (FRC) of the CO₂. See the datasheet of the SCD4x sensor for details how the forced recalibration shall be used.

CMD_ID = 26375

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.PerformCo2SensorFactoryReset

This command resets all CO₂ sensor configuration settings stored in the EEPROM and erases the FRC and ASC algorithm history of the CO₂ sensor. The configuration settings are CO₂ sensor temperature offset (cannot be modified over I2C interface), sensor altitude and the ASC enabled/disabled parameters which are by default stored in the volatile memory (RAM). This command is only available in idle mode.

CMD_ID = 26452

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetCo2SensorAutomaticSelfCalibration

The CO₂ sensor supports automatic self calibration (ASC) for long-term stability of the CO₂ output. This feature can be enabled or disabled. By default it is enabled.

CMD_ID = 26385

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetCo2SensorAutomaticSelfCalibration(status)

Sets the status of the CO₂ sensor automatic self-calibration (ASC). The CO₂ sensor supports automatic self calibration (ASC) for long-term stability of the CO₂ output. This feature can be enabled or disabled. By default it is enabled.

CMD_ID = 26385

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetAmbientPressure

Gets the ambient pressure value. The ambient pressure can be used for pressure compensation in the CO₂ sensor.

CMD_ID = 26400

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetAmbientPressure(ambient_pressure)

The ambient pressure can be used for pressure compensation in the CO₂ sensor. Setting an ambient pressure overrides any pressure compensation based on a previously set sensor altitude. Use of this command is recommended for applications experiencing significant ambient pressure changes to ensure CO₂ sensor accuracy. Valid input values are between 700 to 1’200 hPa. The default value is 1013 hPa. This configuration is volatile, i.e. the parameter will be reverted to its default value after a device restart.

CMD_ID = 26400

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetSensorAltitude

Gets the current sensor altitude. The sensor altitude can be used for pressure compensation in the CO₂ sensor.

CMD_ID = 26422

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetSensorAltitude(altitude)

The sensor altitude can be used for pressure compensation in the CO₂ sensor. The default sensor altitude value is set to 0 meters above sea level. Valid input values are between 0 and 3000m. This configuration is volatile, i.e. the parameter will be reverted to its default value after a device reset.

CMD_ID = 26422

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.StartContinuousMeasurement

Starts a continuous measurement. After starting the measurement, it takes some time (~1.1s) until the first measurement results are available. You could poll with the command “Get Data Ready” to check when the results are ready to read. This command is only available in idle mode. If the device is already in any measure mode, this command has no effect.

CMD_ID = 33

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.StopMeasurement

Stops the measurement and returns to idle mode. After sending this command, wait at least 1000 ms before starting a new measurement. If the device is already in idle mode, this command has no effect.

CMD_ID = 260

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetDataReady

This command can be used to check if new measurement results are ready to read. The data ready flag is automatically reset after reading the measurement values.

CMD_ID = 514

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.ReadNumberConcentrationValuesAsIntegers

Returns the measured number concentration values. The command 0x0202 “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16).

CMD_ID = 790

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.SetTemperatureOffsetParameters(offset, slope, time_constant, slot)

This command allows to compensate temperature effects of the design-in at customer side by applying custom temperature offsets to the ambient temperature.

The compensated ambient temperature is calculated as follows:

• T_Ambient_Compensated = T_Ambient + (slope * T_Ambient) + offset

Where “slope” and “offset” are the values set with this command, smoothed with the specified time constant. All temperatures (“T_Ambient_Compensated”, “T_Ambient” and “offset”) are represented in °C. There are 5 temperature offset slots available that all contribute additively to “T_Ambient_Compensated”. The default values for the temperature offset parameters are all zero, meaning that “T_Ambient_Compensated” is equal to “T_Ambient” by default. The parameters can be changed in any state of the device, i.e. both in idle mode and in measure mode.

CMD_ID = 24754

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.SetTemperatureAccelerationParameters(k, p, t1, t2)

This command allows to set custom temperature acceleration parameters of the RH/T engine. It overwrites the default temperature acceleration parameters of the RH/T engine with custom values. This configuration is volatile, i.e. the parameters will be reverted to their default values after a device reset.

CMD_ID = 24832

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetProductName

Gets the product name from the device.

CMD_ID = 53268

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.GetSerialNumber

Gets the serial number from the device.

CMD_ID = 53299

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.ReadDeviceStatus

Reads the current device status. Use this command to get detailed information about the device status. The device status is encoded in flags. Each device status flag represents a single bit in a 32-bit integer value. If more than one error is present, the device status register value is the sum of the corresponding flag values. For details about the available flags, refer to the device status flags documentation in the data sheet.

CMD_ID = 53766

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.ReadAndClearDeviceStatus

Reads the current device status (like command 0xD206 “Read Device Status”) and afterwards clears all flags.

CMD_ID = 53776

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.GetVersion

Gets the version information for the firmware.

CMD_ID = 53504

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.DeviceReset

Executes a reset on the device. This has the same effect as a power cycle.

CMD_ID = 54020

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.StartFanCleaning

This command triggers fan cleaning. The fan is set to the maximum speed for 10 seconds and then automatically stopped. Wait at least 10s after this command before starting a measurement.

CMD_ID = 22023

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.ActivateShtHeater

Activate the heater feature of the SHT4x sensor. This command allows to use the inbuilt heater in SHT sensor to decontaminate and reverse creep at high humidity. This command activates the SHT sensor heater with 200mW for 1s. The SHT heater measurement done just before deactivation can be read using the command “Get SHT Heater Measurements” after the duration of the heating feature as specified in the SHT4x datasheet. Wait at least 20s after this command before starting a measurement to get coherent temperature values (heating consequence to disappear).

CMD_ID = 26469

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

class sensirion_i2c_sen69c.commands.GetShtHeaterMeasurements

Get the measurement values when the SHT sensor heating is finished.

CMD_ID = 26512

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.ReadMeasuredValuesAsIntegers

Returns the measured values. The command “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16, 0x7FFF for int16).

CMD_ID = 1205

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

class sensirion_i2c_sen69c.commands.ReadMeasuredRawValues

Returns the measured raw values. The command “Get Data Ready” can be used to check if new data is available since the last read operation. If no new data is available, the previous values will be returned again. If no data is available at all (e.g. measurement not running for at least one second), all values will be at their upper limit (0xFFFF for uint16, 0x7FFF for int16).

CMD_ID = 1109

pack()

tx = <sensirion_driver_adapters.rx_tx_data.TxData object>

rx = <sensirion_driver_adapters.rx_tx_data.RxData object>

Result Types

The signal classes specify transformations of the raw sensor signals into a meaningful units. The generated signal types are used by the driver class and not intended for direct use.

class sensirion_i2c_sen69c.result_types.SignalDividedBy10Uint16(scaled_integer_value)

All mass and number concentrations are scaled by a factor 10 to avoid floating point operations on the communication interface.

property value

class sensirion_i2c_sen69c.result_types.SignalDividedBy10Int16(scaled_integer_value)

The VOC and NOx indices are scaled by a factor 10 to avoid floating point operations on the communication interface.

property value

class sensirion_i2c_sen69c.result_types.SignalTemperature(temperature_raw)

Measured temperature in degrees Celsius. The raw value is scaled appropriately.

property value

class sensirion_i2c_sen69c.result_types.SignalHumidity(humidity_raw)

Measured humidity in %RH. The raw value is scaled appropriately.

property value