Our setup is:
Voxl2 mini running PX4 on DSP
ESC mini
Hires IMX214
Tracking OV7251

The Problem:
The drone moves up and down constantly in position mode.

Bench Test:
The on-board Baro readings, when observed in PX4-listener, continuously change (couple of meters over 10 seconds)... the baro-reported temperature gradually increases to 50 deg-c and accordingly the pressure readings decrease. The test is done indoors with Voxl2 mini board in open condition (without enclosure), no propellers.

Request:
We are obliged if you could share the setup info for adding an external baro (BMP280 or similar) with I2C interface.