Python Examples

Example 01 - Basic Readings

Example 1 shows how to get basic CO₂ and temperature data from the STC31. It initializes the sensor with default settings to measure CO₂ in air up to 25% concentration. Open the example in your preferred Python interpreter and run it. You should see some initialization messages print out followed by CO₂ concentration and temperature data every second. Try breathing on the sensor or holding it up to a different CO₂C source and you should see the values change.

Code to Note

The STC31 has four different measurement modes available for the set_binary_gas() function. This lets you change between measuring either up to 25% or 100% CO₂ concentration measured either in nitrogen (N₂) or air. You can adjust the measurement mode by modifying the line of code below with the corresponding concentration/gas:

    # Possible values are:
    # kBinaryGasCO2N2_100   : Set binary gas to CO2 in N2.  Range: 0 to 100 vol%
    # kBinaryGasCO2Air_100  : Set binary gas to CO2 in Air. Range: 0 to 100 vol%
    # kBinaryGasCO2N2_25    : Set binary gas to CO2 in N2.  Range: 0 to 25 vol%
    # kBinaryGasCO2Air_25   : Set binary gas to CO2 in Air. Range: 0 to 25 vol%
    if mySTC31.set_binary_gas(mySTC31.kBinaryGasCO2Air_25):

Example 02 - PHT Compensation

The second example shows how set values for temperature, humidity and pressure to improve the accuracy of the CO₂ data. The example initializes the STC31 to measure in air at concentrations up to 25% volume and then sets the temperature, humidity and barometric pressure to fixed reference values.

Code to Note

As mentioned above, this example sets static compensation values for temperature, pressure and humidity. You may want to adjust these values for your testing environment:

    # These are example compensation variables and you can change them as needed to fit your environment
    pressure = 840
    humidity = 25
    temperature = 25

Example 05 - Self Calibration

Example 5 demonstrates how to enable the STC31's automatic self calibration feature as well as how to perform a forced recalibration. Automatic calibration helps improve the STC31's accuracy when used in applications where the target gas is not present most of the time. Refer to the STC31 Field Calibration Guide for more information on calibrating the STC31.

After initializing the sensor, the code attempts to perform a forced recalibration of the STC31 with a CO₂ value of 0. After performing the forced recalibration, the code enables the STC31's automatic calibration feature and then prints out CO₂ and temperature data every second.