Today I discovered the following:
Weather was -15oC (5oF), wind was 30km/h, gust 39km/h, cold weather.
The issue is that we are inside at 23oC and we go outside with the quad, temperature difference is for sure very high…
REL-ALT is at 0m when I arm the vehicle, I fly it, land it, REL-ALT is now -4m.
It does all sorts of issues like GEOFENCE and RTL are not working correctly, quad stays in the air because altitude is not good…
If I land it on the first try (when REL-ALT is - 4m) I re-arm it, now altitude is good (0m) and id doesn’t drift anymore…
So I suspect that BAROMETER temperature is not implemented correctly with the PixRacer.
As per MS5611 Barometer Datasheet we can read:
Every module is individually factory calibrated at two temperatures and two pressures. As a result, 6 coefficients necessary to compensate for process variations and temperature variations are calculated and stored in the 128-bit PROM of each module. These bits (partitioned into 6 coefficients) must be read by the microcontroller software and used in the program converting D1 and D2 into compensated pressure and temperature values.
Is this part Temperature compensated in the firmware?