Re: BME680 conversion from sensor resistance reading to gas concentration
Unfortunately the BSEC library is closed-source, and only provided as pre-compiled binaries. Therefore we cannot share a formula to calculate our outputs from raw sensor data.
We would recommend if possible to consider the list of supported platforms on BSEC's download page. We have also been providing an Arduino library wrapper for BSEC on our official GitHub page, which includes a list of commonly used and tested MCUs/boards.