@xykon Hi I didnt't told you but have tried 1.16.0.b1 and 1.15.0.1 with both the same results. But with some wires soldered it is working fine. The following schema now is running: External IO Header : PIN 1 - GND PIN 4 - VCC 3V3 SENSORS Header(connected a wire underneath the board) P22 - SDA P21 - SCL I have now a working demo device for this week :)