drone_controller — the ROS 1 (Noetic) drone flight controller

drone_controller is the ROS 1 flight-controller package for AirPost, the autonomous drone parcel-delivery system. It runs on the drone's companion computer (Jetson), bridges the cloud backend to the flight controller over MAVROS, flies delivery missions, and operates the parcel winch.

Status — legacy ROS 1 path. In the integrated AirPost_Drone system this package has been superseded by a ROS 2 / uXRCE-DDS node (ros2_ws/src/airpost_drone), which talks to PX4 directly over DDS. This package is the original MAVROS implementation, kept as the Noetic path.

What it does

backend ──MQTT (command/downlink/…)──►  drone_controller  ──MAVROS/MAVLink──►  Pixhawk
        ◄──MQTT (data/<id>, uplink)───      (this pkg)      ◄──MAVROS telemetry──

• Subscribes to its MQTT command topics and republishes live telemetry (position, velocity, battery, mission status) back to the backend as data/<drone_id> and command/uplink/DevStatusAns/<drone_id>.
• On a delivery request it pushes the waypoint mission to the Pixhawk, arms, takes off, and switches to AUTO so the vehicle flies the route.
• At the drop waypoint it pauses and drives the winch motor to lower and release the parcel.

Scripts (scripts/)

File	Role
MQTT.py	Main node (rosrun drone_controller MQTT.py). The MQTT bridge + telemetry: subscribes to MAVROS topics (/mavros/global_position/global, /rel_alt, /raw/gps_vel, /battery), publishes telemetry to the broker, and routes the ActuatorReq / DevStatusReq commands.
DroneController.py	Mission logic over MAVROS services/topics: clears and pushes the waypoint mission (mavros/mission/push), arms, takes off, sets flight mode, and tracks mavros/mission/reached. At the tag/drop waypoint it triggers the winch.
DCmotor.py	The parcel winch driver: Jetson.GPIO control of the DC motor (clockwise / counter-clockwise / stop) to lower and release the package.

Prerequisites

Software

• ROS 1 Noetic + MAVROS
• Python packages: paho-mqtt, Jetson.GPIO

Hardware

• Pixhawk 4 connected over USB (MAVLink → MAVROS)
• Winch DC motor wired to the Jetson GPIO

Build & run

# clone into your catkin workspace, under catkin_ws/src

# make the entrypoint executable, then build
chmod +x scripts/MQTT.py
cd catkin_ws && catkin_make

# launch
source devel/setup.bash
rosrun drone_controller MQTT.py

launch/all_drone_control.launch brings the node up together with its dependencies.