Disable PX4 internal Barometer, use my own via I2C or Mavlink

Is it possible to disable the internal barometer and use values from my own, either via I2C or mavlink?

I don’t think so - because there is no documentation on this, or obvious mavlink message you might use.
It is likely you could do this with your own driver for a barometer, but you’d have to manually turn off the normal driver that handles barometer input.

Let’s ask someone who would know - @sfuhrer do you know/who would be the best person to ask?

Depending on the PX4 version you use, you should be able to disable the internal one via the parameter SENS_INT_BARO_EN. And then add your external baro to the flight controller, add it to the start up (if not already there), or even add your own driver.
Don’t know if it would work over MAVLink.

Im using 1.13.1. Add my own barometer via an I2C?
Also is there a way to edit the parameter outside of QGC?
Thanks!

I think on 1.13.1 SENS_INT_BARO_EN should be there.

dd my own barometer via an I2C

yes

Also is there a way to edit the parameter outside of QGC?

Yes e.g. MAVLink Shell | PX4 User Guide

I meant was there a file I could get access to rather than via Mavlink?

As for Mavlink, I was thinking about writing it to Raw_Pressure and then using mav_reciever.cpp to write it into the uorb sensor_baro message. Would that not work?

I meant was there a file I could get access to rather than via Mavlink?

Sorry I don’t understand what you mean then.

As for Mavlink, I was thinking about writing it to Raw_Pressure and then using mav_reciever.cpp to write it into the uorb sensor_baro message. Would that not work?

I’d say so yeah. You can also check how it is done for HITL.