What is the operating system used by the raspberryPi as the px4 flight controller?

PX4 Autopilot
1

I’m using the raspberryPi as a flight controller for the px4, and I’m wondering if the OS that the px4 relies on is still Nuttx? Or has it changed to the raspberryPi’s OS?

When I execute the px4 binary code on the raspberryPi I can see the terminal / starting with nsh>.

2

Totally confusing question.
First of all PX4 is a firmware running on a flight controller, not a regular companion computer.
Second: What are you using as flight controller ? …you need something that provides real time data in regards to various sensor readings and also provides fast updates to various outputs so motors and other devices can be controlled as required.

There are additional devices like the Navio2 which can be mounted on top of a RPi, but that sort of setup has usually got its own heavily modified OS for the RPi.

3
  1. I downloaded the raspberry pi image[Emlid Raspberry Pi OS Buster [XZ, 685 MB]];
  2. I compiled the px4 firmware using make emlid_navio2 and uploaded it to the raspberry pi;
  3. I executed the uploaded px4 firmware in the Raspberry Pi and I can see the message starting with nsh>.
    This creates confusion for me, I don’t know if the px4 is using the OS in the image or the Nuttx OS.
4

Obviously got confused with the details:

and

Their forum:

Note on the side: Navio2 has a problem whereby GPS and certain sensors are being ignored at random. This causes mid flight crashes at random and there is no fix.
You can see many reports about this on their forum and you may have also noticed they no longer provide any software updates.

5

@Karl_Schoelpple PX4 does run on Navio 2 - see Raspberry Pi 2/3/4 Navio2 Autopilot | PX4 User Guide (main).

You can run PX4 on any hardware for which there is a port - there aren’t many right now but there have been in the past.

I do understand the confusion. It is far more common to run PX4 on dedicated hardware with a RTOS and use RPi or whatever as a separate companion computer.

@Lqs66 I don’t know the details of the implementation but it pretty much has to run as a host OS (Raspian?) process. I suspect the firmware you download is a patched version that supports RTOS.