Cannot see external barometer data – NO SCALED_PRESSURE3 message

[beyza (BEYZA NUR)]

Hi,
I’m using a Pixhawk Cube Orange+ with ArduSub 4.5.3, and I’ve connected an external DEGZ300 pressure sensor (MS5837-based) via I2C.

QGroundControl detects the sensor as BARO3_DEVID, and I’ve set BARO_PRIMARY to 3rdBaro, so it’s selected as the primary barometer.

However, I want to access the pressure data over MAVLink.
I receive SCALED_PRESSURE and SCALED_PRESSURE2 messages, but SCALED_PRESSURE3 is never published. Therefore, I cannot get the data from the external sensor.

How can I receive BARO3 data via MAVLink?
Is it possible to enable SCALED_PRESSURE3?
Or is there another way to access the external barometer’s data?

Thanks.

[EliotBR (Eliot)]

Hi @beyza,

ArduPilot handles this a little weirdly, by using RAW_PRESSURE as the data for the first barometer.

Accordingly,

@EliotBR

I believe the water depth barometer pressures in this case will show up in SCALED_PRESSURE2, although you should be able to use AHRS2.altitude to get the autopilot’s filtered depth estimate directly.