AGCS — Agrohawk Ground Control Station

Custom build of QGroundControl (v5.0) tailored for the AGH 3000 fixed-wing agricultural sprayer.

Aircraft — AGH 3000

Spec	Value
Type	Fixed-wing crop sprayer (ArduPlane)
MTOW	420 kg
Engine	ICE 100 hp
Spray tank	400 L
Fuel tank	80 L
Flight controller	Pixhawk 6X Pro
Datalink	XBLink (long range)
Backup control	HOTAS via vJoy

Features

Branding

• Custom green + orange color palette
• Agrohawk logo and icons throughout the UI
• App name: AGCS

Fixed-Wing Focused

• Orbit and ROI guidance hidden (irrelevant for fixed-wing)
• Multi-vehicle list hidden (single aircraft ops)
• Airspeed calibration enabled
• Default offline editing set to ArduPilot + FixedWing

ICE Engine Telemetry

Real-time engine instrumentation via EFI_STATUS (MAVLink msg 225) and NAMED_VALUE_FLOAT (msg 251):

• RPM — tachometer with bar gauge (max 8000)
• Fuel level — tank percentage with low-fuel alert (<15%)
• Throttle — position percentage
• Oil pressure — bar gauge with low-pressure alert (<1.5 bar)
• Engine temperature — CHT with over-temp alert (>240°C)

Sprayer Telemetry

Real-time spray system data via NAMED_VALUE_FLOAT (MAVLink msg 251):

• Tank level — 0-400 L with percentage and low-tank alert (<10%)
• Pump pressure — 0-10 bar with high-pressure warning
• Flow rate — L/min display
• Pump status — ON/OFF indicator

Pop-out Telemetry Window

• Click the compact widget to open a full telemetry window
• Detachable — drag to a second monitor
• Native OS window with minimize/maximize/close buttons

FPV Head-Up Display (HUD)

Toggle button on the fly view (above AGH Telemetry widget) enables a full FPV HUD overlay on the video stream:

• Line-only artificial horizon — white horizon line + pitch ladder, no colored sky/ground (video fully visible)
• Heading tape — compass with cardinal points and degree readout
• Speed tape — airspeed (IAS) or ground speed with scrolling ladder
• Altitude tape — relative altitude with scrolling ladder
• VSI — vertical speed indicator bar with numeric readout
• Status bar (3-column layout):
  • Left: ground speed, home distance + direction arrow
  • Center: flight mode + armed state, GPS fix, pump ON/OFF + tank %
  • Right: battery voltage/%, RPM + throttle, fuel + oil + CHT
• Critical alerts — flashing warnings for over-temp, low oil pressure, low fuel
• Compact mode for PiP (picture-in-picture) windows

Architecture

custom/
├── cmake/
│   └── CustomOverrides.cmake      # App name, icon, GStreamer config
├── deploy/
│   └── windows/
│       ├── AGCS.ico               # Windows icon (multi-size)
│       └── AGCS.rc                # Windows resource file
├── res/
│   ├── images/
│   │   ├── icon.png               # App icon source
│   │   ├── logo.svg               # Agrohawk logo
│   │   └── name.svg               # Agrohawk name wordmark
│   └── lua/
│       └── sprayer_telemetry.lua   # Pixhawk Lua script
├── src/
│   ├── AgrohawkPlugin.h/cc        # QGCCorePlugin subclass
│   ├── AgrohawkSprayerTelemetry.h/cc  # NAMED_VALUE_FLOAT handler
│   ├── FlyViewCustomLayer.qml     # Fly view overlay + pop-out window
│   ├── FlyViewVideo.qml           # Video stream pop-out with HUD toggle
│   └── FpvHud.qml                 # FPV Head-Up Display overlay
├── CMakeLists.txt                 # Build config
└── custom.qrc                     # Qt resources

MAVLink Messages

Message	ID	Source	Data
EFI_STATUS	225	Native QGC	RPM, CHT, throttle, fuel flow
NAMED_VALUE_FLOAT	251	Lua script	SPRAY_TNK, SPRAY_PSI, SPRAY_FLW, ENG_FUEL, ENG_OIL

Build

Requirements

• Qt 6.8.3 (MSVC 2022)
• Visual Studio 2022 Build Tools
• CMake 3.22+
• GStreamer 1.22.12 MSVC x64 (Complete installation, not Typical)
  • Runtime: gstreamer-1.0-msvc-x86_64-1.22.12.msi
  • Dev: gstreamer-1.0-devel-msvc-x86_64-1.22.12.msi

Steps

# 1. Clone QGC
git clone --recursive -b Stable_V5.0 https://github.com/mavlink/qgroundcontrol.git qgc

# 2. Copy custom/ into qgc/
cp -r custom/ qgc/custom/

Build (Windows — Automated)

Use the included build_agcs.bat script (must run in cmd.exe, not PowerShell):

C:\CC\build_agcs.bat

The script handles the full pipeline:

1. Sets up MSVC x64 environment via vcvarsall.bat amd64
2. Adds Qt CMake + Ninja + GStreamer to PATH
3. Cleans previous build directory
4. Configures with qt-cmake (Ninja generator, Release)
5. Builds with cmake --build
6. Deploys Qt DLLs with windeployqt + GStreamer DLLs and plugins

Output: C:\CC\qgc\build\Release\AGCS.exe

Important: Always build from cmd.exe — the MSVC vcvarsall.bat does not work in PowerShell. Running from PowerShell will cause missing C++ standard library headers (type_traits, memory, etc.)

Build (Manual)

If building manually, ensure vcvarsall.bat amd64 is called first in the same cmd session:

"C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" amd64
set PATH=C:\Qt\Tools\Ninja;C:\Qt\Tools\CMake_64\bin;%PATH%

call C:\Qt\6.8.3\msvc2022_64\bin\qt-cmake.bat -B qgc\build -S qgc -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build qgc\build
C:\Qt\6.8.3\msvc2022_64\bin\windeployqt.exe qgc\build\Release\AGCS.exe --qmldir qgc\src

Known Issues

• Locale bug: QGC may crash or show parsing errors if Windows regional settings use comma as decimal separator. Set LANG=en_US or run with --locale en_US if you encounter this.
• qt-cmake.bat must use call: When invoking qt-cmake.bat from another .bat file, always prefix with call — otherwise the calling script terminates after qt-cmake finishes.
• QtMultimedia UVC crash (Qt 6.8.3): QVideoFrame::unmap null pointer dereference in Qt6Multimedia.dll causes a crash after ~5 minutes of USB camera (UVC) video streaming. This is a known Qt 6.8.3 bug. UVC cameras use the QtMultimedia path (FlightDisplayViewUVC.qml) regardless of GStreamer being enabled. Workaround: use RTSP/UDP video sources instead of USB cameras, which use the GStreamer pipeline and are not affected.
• GStreamer plugin path: On Windows, GStreamer.cc looks for plugins at <appDir>/../lib/gstreamer-1.0/. The build script deploys them to build/lib/gstreamer-1.0/ (one level above build/Release/). If RTSP/UDP video shows "Awaiting Video", verify the plugins are in the correct path.

Pixhawk Lua Script

Copy res/lua/sprayer_telemetry.lua to the Pixhawk SD card at APM/scripts/.

The script reads analog sensors and sends telemetry at 5 Hz:

Variable	ADC Pin	Range	Description
SPRAY_TNK	14	0-400 L	Spray tank level
SPRAY_PSI	15	0-10 bar	Pump pressure
SPRAY_FLW	16	0-20 L/min	Flow rate
ENG_FUEL	17	0-80 L	Fuel tank level
ENG_OIL	18	0-8 bar	Oil pressure

Adjust ADC pin numbers and calibration values in the script to match your hardware.

Testing

With SITL + X-Plane 12

1. Run ArduPlane SITL with --model xplane
2. Connect X-Plane 12 via UDP
3. Open AGCS — it auto-connects on UDP 14550

With Mock Link

1. Open AGCS
2. Go to Application Settings → Mock Link → Create ArduPilot FixedWing

License

Based on QGroundControl, licensed under Apache 2.0.

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Agrohawk — Agricultural drone technology