uThing::VOC sensor data output¶
The following table shows the data outputs from the device:
|Temperature||°C||-40 - +85||ambient temperature estimated outside the device|
|RelativeHumidity||%RH||0 - 100||ambient Relative-Humidity (*) estimated outside the device|
|Pressure||hPa||300-1100||atmospheric (barometric) pressure (1000 hPA = 1 bar)|
|GasResitance||Ω||1K-1M||hot-plate raw gas resistance (ohm)|
|IAQ||-||0-500||Air Quality Index (check BSEC classification)|
|IAC_accuracy||-||0-3||0: not-fixed-yet (IAQ invalid), 3: maximum-stability|
|equivalentCO2||ppm||-||CO2 equivalent estimate|
|eqBreathVOC||ppm||-||breath-VOC concentration estimate|
(*) relative humidity
Relative humidity refers to the ratio of the amount of moisture in the air at a certain temperature to the maximum amount of moisture that the air can retain at the same temperature. In other words, relative humidity measures how much of the moisture capacity of the air is used.
uThing::VOC™ provides three different reporting formats for the processed BSEC data. Check the configuration section below for instructions on how to change this output format.
JSON is the default output reporting format due to its ubiquitous use on IoT applications. It’s also human readable. An output example is shown below.
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For applications where a simple mean for data-logging is needed, the board can be configured to output the data in CSV format (comma separated values).
When the board is configured in this mode, the column order is the following:
tip: Exporting data to Excel
As a quick way to do some simple dataloging into a file, the sensor data can be sent to a plain text file with the following command:
$ cat /dev/ttyACM0 > airQuality.csv
Additionally, if the “&” symbol is added at the end of the command, the process will be forked, and the system will keep storing the data until the user logs out or the dongle is disconnected.
Then the generated file can easily be opened in Excel or any spreadsheet application for evaluation.
Optionally, the column formatting can be pasted into the first line of the generated CSV file, simplifying the analysis on the spreadsheet apps.
The 'human-readable' format reports a more descriptive output that includes the measuring units.
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