PX4 -> QGC connection through USB for VOXL2

qt

The readme to help you use my scripts :

./readme.md :

# VOXL USB NCM Setup for ModalAI Starling 2 Max

## Context & Objective

> This repository provides scripts and configuration files to enable **USB NCM** (Network Control Model) networking between a **ModalAI Starling 2 Max** drone and a **Linux PC**.
The goal is to transfer files faster than **Wi-Fi** or **ADB**, using a direct USB Ethernet link. **USB NCM** creates a virtual Ethernet interface over USB, allowing high-speed IP communication for **SSH**, `rsync`, or other tools.

---

## Features

Automatic configuration of USB NCM on both drone and PC.
Systemd services to persist configuration across reboots.
NetworkManager drop-in to prevent interference on the PC.
IP addressing and MTU tuning for optimal performance.

## Installation

Run the orchestrator script from the root of this repository:

```bash
chmod +x config-voxl-usb-ncm.sh # Already executable normally
./config-voxl-usb-ncm.sh

Options

--pc : Configure only the PC.
--drone : Configure only the drone (requires adb).
--uninstall : Stops and disables services, removes scripts, and cleans NetworkManager configuration.

Exemples

# Install on both PC and drone
./config-voxl-usb-ncm.sh

# Install only on PC
./config-voxl-usb-ncm.sh --pc

# Install only on drone
./config-voxl-usb-ncm.sh --drone

# Uninstall everything
./config-voxl-usb-ncm.sh --uninstall

# Uninstall only on PC
./config-voxl-usb-ncm.sh --pc --uninstall

# Uninstall only on drone
./config-voxl-usb-ncm.sh --drone --uninstall

Configuration Details

IP Addresses
- Drone: 10.55.0.1/30 on usb0
- PC: 10.55.0.2/30 on enx* (USB Ethernet interface)
MTU
- Default: 1500 (After some tests, 1500 seems to be the maximum for NCM in USB2.1)
Systemd Services
- Drone: voxl-usb-ncm.service (oneshot, sets up USB gadget and configures usb0)
- PC: voxl-usb-ncm.service (persistent, monitors enx* and configures IP)
NetworkManager
- Adds /etc/NetworkManager/conf.d/unmanaged.conf which prevents NetworkManager from interfering with the USB interface.

How to Connect

Once installed and both devices are connected via USB:

# It will ask password
ssh root@10.55.0.1

# We can put the password in parameter by using sshpass.
# By default, the password on the drone is oelinux123.
sshpass -p oelinux123 ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root@10.55.0.1

File Transfer with rsync

# Example to copy a folder from PC to drone:
rsync -ah --info=progress2 --partial --inplace /path/to/local/folder root@10.55.0.1:/path/on/drone/

# Example to copy a folder from drone to pc:
rsync -ah --info=progress2 --partial --inplace root@10.55.0.1:/path/to/drone/folder /path/on/pc

File Overview

File : on_drone/voxl-usb-ncm-setup.sh
- Destination : /usr/local/sbin/ on drone
- Purpose : Creates USB gadget NCM function, configures usb0 with IP 10.55.0.1/30 and MTU
File : on_drone/voxl-usb-ncm.service
- Destination : /etc/systemd/system/ on drone
- Purpose : Runs setup script at boot (oneshot)
File : on_pc/voxl-usb-ncm-setup.sh
- Destination : /usr/local/sbin/ on PC
- Purpose : Monitors enx* interface, assigns IP 10.55.0.2/30
File : on_pc/voxl-usb-ncm.service
- Destination : /etc/systemd/system/ on PC
- Purpose : Starts monitoring script at boot
File : on_pc/unmanaged.conf
- Destination : /etc/NetworkManager/conf.d/
- Purpose : Marks enx* interfaces as unmanaged
File : config-voxl-usb-ncm.sh
- Purpose : Orchestrates installation/uninstallation on PC and drone