lua: LVGL touch UI variant of the configurator (draft)

[burzl89]

Following up on the Discord discussion — this adds lua/mLRS-lvgl.lua, an LVGL-based touch UI variant of the configurator, alongside the unchanged classic mLRS.lua.

This corresponds to the v1.0.0 release in my staging repo, where I keep more detailed release notes and test status while this settles.

What it does

• Full LVGL widget UI (EdgeTX 2.11+): everything touch-operated
• Native on-screen keyboard for the bind phrase and STR6 params, input sanitized to the mLRS charset
• Native popup pickers for Mode / RF Band / Ortho and all list params; options outside the allowed_mask are filtered out
• numberEdit with min/max/unit for numeric params, scrollable Edit Tx/Rx pages
• Reactive attributes instead of manual redraws; the LVGL tree is only rebuilt on page/data changes
• Two switchable color themes (Tools page, persisted on the SD card): the dark style from the screenshots plus a high-contrast theme — added after Olli's feedback about sunlight readability and older eyes
• Layouts: 800x480, 480x272 and 480x320 — all three confirmed on real hardware, themes included
• The mBridge/CRSF protocol section is byte-identical to the classic script (aligned after Olli's maintainability feedback)
• Radios without LVGL show a hint to use the classic script instead

Status

• Confirmed working on real hardware: 800x480 (TX16S MK3), 480x272 (original TX16S), and 480x320 — all three including the theme switcher
• Portrait radios (NV14/EL18) intentionally not supported yet

Draft on purpose — happy to align with #448 (thanks @jlpoltrack for the groundwork and the blessing to build on it) and with Olli's own WIP version. Colors, defaults and file naming are all open for discussion.

[burzl89]

Thanks for the look, and fair point re: AI-generated architecture drift — I went back and aligned the whole mBridge/CRSF/parameter-handling backend so it now diffs identically against lua/mLRS.lua (down to the comments, including a couple of dead-but-harmless helper functions I had trimmed). The only remaining difference is the popup rendering, which is inherent to the two approaches (LVGL reactive widgets vs. lcd.draw* calls) — everything else should patch cleanly across both files now.

Still waiting on a 480x272 test on a real (non-MK3) TX16S, hopefully within the week. No pressure on timing from my side — happy to align with whatever direction you and JLP's work end up taking.

[burzl89]

Update: 480x272 has now been confirmed working on a real original TX16S (second tester, different radio than mine). So at this point both 800x480 (MK3) and 480x272 are hardware-verified, including the theme switcher. 480x320 shares the same compact layout code path as 480x272 (just a bit more vertical space) but hasn't been independently tested.

Tagged as v1.0.0-rc3 in my staging repo: https://github.com/burzl89/mlrs-lua-mk3/releases/tag/v1.0.0-rc3

[burzl89]

Update: 480x320 has now also been confirmed working, so all three supported screen classes (800x480 MK3, 480x272, 480x320) are hardware-verified, themes included. Tagged this as a stable v1.0.0 in my staging repo rather than another RC: https://github.com/burzl89/mlrs-lua-mk3/releases/tag/v1.0.0

Still a draft here of course — whatever makes sense once you've had a chance to look, combine with your own version, or just take pieces of it.

[burzl89]

Marked this as ready for review now that all three screen classes are hardware-confirmed. No pressure on the outcome though — happy to have pieces of it folded into whatever you and JLP end up converging on.