MAV-LUA

MAVLink telemetry for your radio: a compact flight display, status-message viewer, and opt-in ArduPilot parameter browser for ExpressLRS.

Features

• Navigation: attitude indicator, flight mode, battery, link quality, satellites, altitude, and Mission Planner-style ready-to-arm status.
• Home guidance: north-up direction-from-home marker and distance. The filled marker changes contrast across the horizon.
• Messages: the latest 20 MAVLink status messages, with severity, repeat counts, and full-width text wrapping.
• Parameters: Mission Planner-style first-level categories backed by compact, firmware-specific ArduPilot name databases. Browsing is local; values are read only when selected.
• Small-radio friendly: native bitmap text, integer drawing, bounded memory, and both telemetry-screen and Tools entry points.

Navigation	Messages

Categories	Browse	Edit	Review

Navigation and Messages have been tested on Tango 2/FreedomTX 1.4 and TBS Alpha/EdgeTX 2.11. The v0.1.3 category-first parameter browser, exact-name reads, editing, verified saves, and readiness path were tested with ArduPilot Plane 4.8 on the Alpha setup described below.

Installation

Download the matching package from Releases:

Firmware	Package
EdgeTX 2.11 RC1 or newer	MAV-LUA-<version>_source.zip
Earlier EdgeTX/FreedomTX	MAV-LUA-<version>_precompiled.zip

1. Copy the package's complete SCRIPTS folder to the SD card, plus WIDGETS on color radios. Put uninstall-mav-lua.bat at the card's top level, beside SCRIPTS.
2. Select MAV as a telemetry screen, or launch MAV from Tools on radios whose telemetry menu reserves PAGE.
3. Discover telemetry sensors, then reload the model or restart the radio.

Updating an existing install

Run uninstall-mav-lua.bat from the card's top level with the card in a reader on the PC, not in the radio. It removes every MAV-LUA file from the card it is run from, including old .luac caches that would otherwise shadow a new package, so no manual deletion is needed. Add /y to skip the confirmation prompt.

Only MAV-LUA files are deleted; nothing else on the card is touched and the card is never formatted. The script refuses to run if it cannot find a SCRIPTS folder beside itself.

Use an ArduPilot vehicle over ExpressLRS MAVLink mode. Disable other telemetry scripts that consume the same CRSF queue.

Controls

Input	Action
PAGE	Cycle Navigation, Messages, and Parameters
Roller	Scroll messages, browse parameters, or edit a value
Enter	Select, confirm, or open the parameter editor
Menu in Parameters	Change the numeric edit step or return to Load
Exit	Back out or discard an edit

On touch radios, horizontal swipes change pages, vertical swipes scroll, and taps select. Hold Exit to close the Tools application.

If Enter still changes pages after updating, the radio is loading an old cache. Run uninstall-mav-lua.bat, install the complete package again, and restart.

Ready-to-arm status

READY means the autopilot reports its pre-arm check healthy, or that check is disabled. NOT READY means an enabled pre-arm check is failing. ARMED is driven by the explicit armed bit, and READY? means readiness or arm telemetry is missing or stale. Only READY and ARMED are inverted for at-a-glance recognition. Status-message text never changes this indicator.

Parameters

Parameters require EdgeTX 2.11 or newer and the matching TX-side bridge proposed in ExpressLRS PR #3779. Stock ExpressLRS MAVLink telemetry does not expose autopilot parameter replies to handset Lua. The bridge is TX-only; it preserves normal telemetry conversion and the existing MAVLink OTA uplink.

• Press Load to read AUTOPILOT_VERSION and select the matching vehicle/version database.
• Browse first-level categories and parameter names locally. Each eight-name page is a direct 128-byte read from the packaged database and sends no parameter requests.
• Repeated numbered groups are nested under one family (RC contains RC, RC1 through RC16), cutting the first level roughly in half.
• Select a name to fetch that one value. Names for disabled or board-specific features may report Parameter unavailable.
• Menu changes the step size while editing.
• Enter opens review. Choose Save and wait for Saved and verified; Exit discards the draft.

Writes require a fresh heartbeat. MAV rereads the original value, sends PARAM_SET once, and requires a separate matching readback before reporting success. An unconfirmed write is never repeated automatically.

v0.1.3 includes read-only Plane and Copter name databases generated from official ArduPilot 4.6, 4.7, and 4.8-dev metadata. It never downloads all live parameters or writes a runtime database. Only the current eight categories or names are retained. Parameter descriptions, enum labels, bitmask editors, search, PX4, and other autopilot families are not yet included.

Parameter database provenance

v0.2.0 roadmap: firmware-agnostic bridge and radio-side firmware adapters

Changelog · Protocol notes · GPL-3.0 license