Log Sensors from Arduino to SDCards in PixHawk

I would like to log various sensors connected to an Arduino. My goal is, that the sensors just send their data and then the software just logs the sent values into the main log file. At best, i hope to see them in Missionplanner.
I already tried to make them communicate over serial and mavlink. Unfortunately, until now I had no success, not even a pre defined message.
I could not get them to communicate with each other, which was my first approach. Later i want to try to log the send message.

I would appreciate any help from the colleagues.
Best Regards