ArduPilot firmware: install Copter, Plane, Rover or Sub on any board

ArduPilot is autopilot software for many kinds of vehicles. The same project produces several firmwares: ArduCopter for multirotors, a Heli build of Copter for traditional helicopters, ArduPlane for fixed-wing aircraft and QuadPlane VTOLs, Rover for cars and boats, ArduSub for underwater vehicles and Antenna Tracker for tracking antennas. Each is compiled for each supported board, because pin maps, sensors and memory differ from board to board.

The builds are published on firmware.ardupilot.org in folders per vehicle, with stable and beta releases plus the latest development build. Picking a file by hand means knowing your exact board name, the vehicle, the release and the right file type. FlySpark reads the server's manifest, which lists every build with its board ID, vehicle, version and file format, and does the matching for you.

An .apj file is the normal update image. It contains the firmware plus its board ID and is written through the ArduPilot bootloader, which is already on the board if it has run ArduPilot before. This is what ground stations use for updates, and it never touches the bootloader itself.

A _with_bl.hex file contains the ArduPilot bootloader and the firmware together. It is written in the chip's DFU mode, which every STM32 flight controller has in ROM. Use it the first time ArduPilot goes on a board, for example when converting a Betaflight or INAV board. DFU flashing erases the whole chip.

A .bin or .abin file is used for other routes, such as loading from an SD card on boards that support it. FlySpark uses .apj for updates and _with_bl.hex for DFU installs. In custom file mode it accepts .apj, .px4 and .hex files.

Choose Runs ArduPilot when the board already has ArduPilot on it, even an old version. FlySpark reboots it into the bootloader, checks the board ID against the image, erases, writes and verifies. Nothing outside the firmware area changes, so your parameters and calibrations stay.

Choose First install (DFU) when the board runs Betaflight or INAV, has never been flashed, or has a damaged bootloader. Put the board in DFU mode by holding its BOOT button while plugging in USB. FlySpark writes the _with_bl.hex image, which replaces everything on the chip including the bootloader. If you connect a board that runs Betaflight or INAV and pick the normal method, FlySpark tells you to use the DFU option instead, because those firmwares have no ArduPilot bootloader.

Every ArduPilot board has a numeric board ID, and every .apj image records the ID it was built for. When a board is in the ArduPilot bootloader, FlySpark reads that ID and filters the list to matching builds. Some boards share compatible IDs, and FlySpark knows those pairs.

When the board runs ArduPilot, the board name in its USB description helps narrow the list. When it runs Betaflight or INAV, FlySpark reads the target name and suggests the ArduPilot board with the same hardware where one exists. You can always search by name instead, and the search covers every board on the server.

Similar names can mean different hardware: a board and its V2 or a Pro variant often need different builds. If you are not sure, check the name printed on the board or in the manufacturer's documentation, and let FlySpark's board ID check catch a mismatch before anything is written.

Flashing needs a wired USB connection, so the tool runs in the FlySpark app on Android with a USB OTG cable or adapter. It is not offered on iPhone, which has no USB access for apps, and it is not part of the web version. In the browser you can try a dry run against a simulated bootloader in the demo to see the steps.

Inside the ArduPilot and MAVLink ground station, Setup has its own Install firmware page. It shows the boards and vehicles, guesses your board from its boot messages, and on Android installs over USB. On a telemetry radio, Bluetooth or Wi-Fi link it lets you browse firmware but asks for a direct USB connection to install.

Updating within the same major version keeps parameters and needs no extra work. After a jump between major versions, read the release notes for parameter changes, then connect the ground station and check the Setup status chips, especially the frame type, flight modes and failsafes.

After a first install, the board starts with default parameters. Work through the mandatory setup: frame type for Copter, accelerometer, compass, radio calibration, flight modes, failsafe and, for Copter, initial tune parameters. FlySpark's ArduPilot ground station covers all of these.