A example how to send from a SGPC3 (ESS-C3 from Sensirion) to send to The Thing Network
I've used the online compiler of mbed.com: https://ide.mbed.com/compiler Just import it via this url to your compiler.
You can use this Decoder on your Application: https://gist.github.com/maxmayr95/162a1a2ff06568b4cbe18be6f31463fd
This example is based on https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-mbed5-lorawan/ and https://os.mbed.com/users/loopsva/code/scd30_HelloWorld/. I've combined them to a working solution for The Things Network, Mbed and SCD30.