@jaredwolff I downloaded the binaries from the Bosch site and the source library from the github repo. In the binaries archive is an arduino library with an example with the error, you found.... The github repo has no binaries and I couldn't get it up with the binary. The binary distribution of essential code makes it more complicated than it could be... The integration in platformio is not to complicated in my code. I only had to add (after investigating for some hours) build_flags = -Llib/BSEC/src/esp32/ -lalgobsec