how to calculate CO2 equivalent and VOC using PIC32MX370/470 MCU?

[ankur]

Hello,

The BME680 alone can only output raw temperature, absolute pressure, relative humidity, and gas resistance.

How can I calculate CO2 equivalent and VOC without the library?

I did not find any formula neither in the BME680 datasheet nor in the API.

I am using  PIC32MX370/470 MCU.

Best regards

Ankur

[Vincent]

Please check the BSEC lib built for you. 

The compiling option is with default setting. If there is anything wrong with the integration, it may caused by the option difference.

The release lib is already tested by simulator of Mplab and works.

Please check it.

[ankur]

Hello Vincent,

Thanks for the library.

As per your provided library, I'm getting the value of all parameters except the "co2_equivalent" and "breath_voc_equivalent" parameter.

Kindly suggest how can I get these two parameters value using the provided library.

Thank you

[Vincent · Accepted solution]

The following two output virtual sensor is the sensor you are requested.

BSEC_OUTPUT_CO2_EQUIVALENT = 3, /*!< co2 equivalent estimate [ppm] */
BSEC_OUTPUT_BREATH_VOC_EQUIVALENT = 4, /*!< breath VOC concentration estimate [ppm] */

They are part of the lib which i released to you. 

In the example code bsec_integration.c in the release package,  you can find the function bme680_bsec_update_subscription.   you can add these two output sensor into the enable senser list.  then you should able to get those two output from lib.

[ankur]

Hello Vincent,

Thanks for your suggestion.

 I got output for these two parameters, co2 equivalent & breath VOC equivalent.