QUT Autopilot Pixracer

QUT Open Source Autopilot Hardware (QUTOpenFCU)

🏛️ University Property & Acknowledgement

This project and its contents have been supported by the Queensland University of Technology (QUT). It was developed as an in-house hardware solution for UAV units at QUT. QUT acknowledges the Turrbal and Yugara, as the First Nations owners of the lands where QUT now stands.

Project Overview

This project involves refactoring, building, programming, and testing an open-source flight module design to serve as a replacement for current hardware. The design stems from the pixracer design, produced by Nick Arsov and Phillip Kocmoud and architected by Lorenz Meier, David Sidrane and Leonard Hall. (https://docs.px4.io/v1.12/en/flight_controller/pixracer.html)

The primary objective is to create an alternative to the difficult-to-source off-the-shelf Pixhawk 6. This work builds upon a edited pixracer version produced by KAI (Wesley) in 2022.

The final demonstrator capabilities include:

• Loading open-source firmware with customizations.
• Connecting to QGroundControl.
• Basic operations for manned flight on a simple airframe.
• Autonomous flight via ros2 and internal positioning system

Hardware Specifications & Modifications

The core design is based on the AUAV Pixracer, which is the FMUv4 generation of Pixhawk autopilots.

• Main System-on-Chip: STM32F427VIT6 rev.3 CPU (180 MHz ARM Cortex® M4).
• v2 Sensor Suite: Invensense ICM-42688-p (Accel / Gyro), Invensense ICM-20608-G (Accel / Gyro), MS561101BA03-50 (Barometer), and LIS3MDLTR (Mag).
• v2 Board Modifications: The design includes small placement changes to the SD card, C, and R components. It also introduces new interfaces, including a Reset Button and a BOOT0 Button.

Firmware

• The PX4 firmware is loaded onto the STM chip using DFU.
• Small modifications were required for drivers and SPI chip select pins.
• Mavlink 8266 firmware was utilized for the external WiFi ESP-01 module.
• Custom firmware was also designed to test sensor communication, using the onboard LED to display different colors for different communication failures.

Current Issues & Future Work (v3 Development)

Known Board Issues (v2)

• The D4 label is missing from the board.
• The labels are too small to read.
• There is no thermal relief on the ground pads, and the board name is out of date.
• The USB data lines are not the same length.
• One of the accelerometer sensors needs to be rotated 90 degrees.
• A breakout for serial debugging output needs to be added.
• The SD card footprint should be reversed for better access.
• The STM chip is not connected to 3.3v.
• Offboarding mode errors on QGroundControl

Future Work

• Fixing the outlined issues and setting up external production.
• Designing an outer case with proper sensor specs, including barometer foam protection and chip vibration isolation techniques.
• Validating external component connections, PX4 firmware, and QGroundControl configurations.
• Considering turning the design into a Pi header with required isolation.

📸 Project Showcase

Operation videos and development images can be found inside the Showcase folder

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Author Credentials

Name: Joshua Hecke Student ID: n11585382 Role: Project Developer

📄 License Disclaimer

The base AUAV Pixracer is an open hardware design licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license.