Lua Scripts

The Lua Scripts tab installs and manages ArduPilot Lua scripts on the flight controller — curated applets from a bundled catalog, or your own .lua files — over MAVLink-FTP. It is a product-shaped front end for ArduPilot’s onboard scripting: enable the VM, drop scripts on the SD card, and reboot to run them, without a file manager or the raw parameter tree.

Where it is

Lua Scripts is an Expert-mode, scripting-capable surface. It only appears when the connected flight controller reports the SCR_ENABLE parameter — and that parameter exists only if the firmware was built with the Lua VM. A board on a stock, non-scripting build simply does not expose it, so the tab stays hidden. Switch on Expert mode (top-right) and, if the firmware supports scripting, the Lua Scripts tab appears in the sidebar.

Capability states

The tab adapts to what the firmware reports:

  • Unsupported — no SCR_ENABLE at all. The firmware has no Lua VM; flash a scripting-capable build to use scripts. Nothing to configure here.

  • Disabled — SCR_ENABLE is 0. A one-click Enable scripting turns the VM on, and if the current SCR_HEAP_SIZE is low it stages a sane heap value at the same time. Both are staged and written like any other change, followed by a reboot to bring the VM up.

  • Enabled — scripting is running. The tab shows the configured heap and warns if it is low, since an undersized heap is a common cause of scripts failing to load.

Installing scripts

Two ways to get a script onto the aircraft:

  • Install a curated applet — one click from a bundled catalog of common ArduPilot applets. These are GPL-3.0, redistributed from the firmware’s libraries/AP_Scripting/applets tree.

  • Upload your own — pick a local .lua file and upload it.

Both write to the scripts directory over MAVFTP — /APM/scripts on ArduPilot hardware, or /scripts on SITL. Installed scripts are listed, and you can remove one from the same list. ArduPilot only loads scripts at startup, so a reboot applies anything newly installed or removed.

Each catalog card shows a one-line summary with an expandable details section and best-effort prerequisite checks behind its info bubble — for example, a VTX applet notes that it wants a serial port set to Scripting, and a rangefinder applet notes that it wants RNGFND* configured. These prerequisites are warnings, not blockers: you can install regardless, and they are there to flag the common “installed but did nothing” cases.

Note

Scripts live on the SD card, so a mounted SD card is required — both to install them and for the firmware to run them. On a board with no card (or an unreadable one) there is nowhere for the scripts to go.

On the firmware side, the ArduPilot wiki is canonical for onboard scripting: Lua Scripts.