HUB75 bugfixes for 4-scan and chained panels + new "Seengreat" pinout by softhack007 · Pull Request #5662 · wled/WLED

softhack007 · 2026-06-03T20:13:46Z

Improvements:

new -S3 pin-out for Seengreat RGB Matrix Adapter Board (https://seengreat.com/wiki/186)
allow up to 128 pixels wide panels, prevent uint8 overflow for 128px panels

Bugfixes for 4-scan (aka QS) panels

prevent panels going flatter each time that cfg.json is saved (32x32->16x64->8x128->4x128)
correct VirtualMatrixPanel setup: need to use real panel dimensions, not modified mxconfig dimensions
only set chainType when chain length > 1
use a chaintype that does not flip the display upside-down

Summary by CodeRabbit

Summary

New Features
- Added support for an additional ESP32-S3 HUB75 pinout configuration for broader hardware compatibility.
Bug Fixes
- Improved HUB75 panel initialization for HS vs QS types, including corrected virtual/quad-scan sizing and chaining behavior.
- Updated reported pin/matrix dimensions for quad-scan layouts.
- Fixed pixel color reads to return consistent RGB values.
- Improved robustness by handling display/driver allocation failures gracefully with fallback.
- Added clearer handling for unsupported/unknown HUB75 panel configurations.

https://seengreat.com/wiki/186

align with settings page that also allows up to 64x128 per panel

* prevent panels going flatter each time that cfg.json is saved * correct VirtualMatrixPanel setup: provide real panel dimensions * only set chainType when chain length > 1 * use a chaintype that does not flip the display upside-down

coderabbitai · 2026-06-03T20:15:24Z

No actionable comments were generated in the recent review. 🎉

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Run ID: e8d97ea9-09d3-409b-82d4-3d4e6c422a54

📥 Commits

Reviewing files that changed from the base of the PR and between c862008 and 8e6d214.

📒 Files selected for processing (1)

wled00/bus_manager.cpp

🚧 Files skipped from review as they are similar to previous changes (1)

wled00/bus_manager.cpp

Walkthrough

BusHub75Matrix now tracks quad-scan state, updates HUB75 sizing and driver selection, reorganizes ESP32-S3 pinout mapping, and changes virtual display construction plus pixel and pin reporting.

Changes

HUB75 virtual and quad-scan configuration

Layer / File(s)	Summary
Virtual init and scan-mode sizing `wled00/bus_manager.cpp`, `wled00/bus_manager.h`	The class adds `_isQuadScan`, initializes `_isVirtual` and `_isQuadScan`, normalizes panel and chain values as unsigned, clamps chain length, caps half-scan dimensions, applies quarter-scan sizing and driver selection, and changes panel allocation to `new(std::nothrow)` with null-checking.
ESP32-S3 pinout selection `wled00/bus_manager.cpp`	The ESP32-S3 HUB75 pinout branches are reorganized, a `SEENGREAT_V2_S3_PINOUT` mapping is added, the fallback S3 mapping changes, and unsupported board configurations now stop at compile time.
Virtual display setup and output reporting `wled00/bus_manager.cpp`	Virtual mode now selects `CHAIN_TOP_RIGHT_DOWN` for chained panels, enables virtual rendering from chaining or QS mode, builds `virtualDisp` with physically clamped dimensions, returns raw pixel buffer values, and reports quad-scan-adjusted pin dimensions.

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

wled/WLED#4950: Also changes BusHub75Matrix constructor logic in wled00/bus_manager.cpp, including chain_length typing and clamping behavior.
wled/WLED#5026: Touches HUB75 virtual panel setup and related BusHub75Matrix logic, including quad-scan state and output handling.
wled/WLED#5647: Also changes HUB75 quarter-scan handling and HUB75_I2S_CFG::FM6124 driver selection in wled00/bus_manager.cpp.

Suggested labels

hardware, Awaiting testing

Suggested reviewers

DedeHai
netmindz

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main changes: 4-scan/chained HUB75 fixes and a new Seengreat pinout.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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_{Comment @coderabbitai help to get the list of available commands.}

change local variables to unsigned (=32bit)

ensure that BusHub75Matrix::getPixelColor() returns RGBW format, not RGBA. Currently busses.getPixelColor() is not used by the WLED core.

DedeHai · 2026-06-04T18:15:51Z

@softhack007 offtopic: what is up with the rabbit adding random labels?

softhack007 · 2026-06-04T22:24:08Z

@softhack007 offtopic: what is up with the rabbit adding random labels?

That was an experiment, I've allowed it to directly add the labels it suggests. Initially it looked meaningful, but it's true we see to many "random" labels. I'll switch that feature off.

* prevent using mxconfig.mx_height before it was set *untangle virtual / physical panel dimensions from _isVirtual

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

softhack007 · 2026-06-29T19:13:30Z

To-Do list for testing:

softhack007 · 2026-06-30T11:04:46Z

🤔 The wrong panel dimensions problem came back for double-scan panels. but only with a "-O2" build. Everything works as it should in a normal "-Os" build.

This might be a pre-existing read/write race / memory error / use-after-free issue that only surfaces with -O2. WLED is built with -Os, so this problem is not blocking, but worth to chase this down later.

Edit: my fault, not a bug. I've accidentally booted an old firmware partition 😅

* comment update * put bool condition into brackets

coderabbitai · 2026-06-30T11:32:12Z

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DedeHai

I have no hardware but changes look good to me besides the mask

fastled-slim does not need the " & 0x00FFFFFF" mask

…#5662) Improvements: * new pinouts for Seengreat RGB Matrix Adapter Board (https://seengreat.com/wiki/186) * allow up to 128 pixels wide panels, prevent uint8 overflow for 128px panels Bugfixes for 4-scan (aka QS) panels * prevent panels going flatter each time that cfg.json is saved (32x32->16x64->8x128->4x128) * correct VirtualMatrixPanel setup: need to use real panel dimensions, not modified mxconfig dimensions *only set chainType when chain length > 1; use a chaintype that does not flip the display upside-down

softhack007 added 3 commits June 3, 2026 22:02

add SEENGREAT_V2 pin-out (S3)

834a902

https://seengreat.com/wiki/186

allow HUB75 panel width up to 128px

f1a99ce

align with settings page that also allows up to 64x128 per panel

bugfixes: 4-scan HUB75 driver setup

c530e13

* prevent panels going flatter each time that cfg.json is saved * correct VirtualMatrixPanel setup: provide real panel dimensions * only set chainType when chain length > 1 * use a chaintype that does not flip the display upside-down

coderabbitai Bot added enhancement hardware (Likely) Setup-specific issue, e.g. flickering LEDs Awaiting testing labels Jun 3, 2026

prevent 8-bit wrap-around on 128x64 4-scan panels

1ee4c61

change local variables to unsigned (=32bit)

softhack007 removed the Awaiting testing label Jun 3, 2026

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coderabbitai Bot added the Awaiting testing label Jun 3, 2026

softhack007 marked this pull request as draft June 3, 2026 20:35

comment correction

22fead8

coderabbitai Bot added the good job label Jun 3, 2026

DedeHai reviewed Jun 4, 2026

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Comment thread wled00/bus_manager.cpp Outdated

netmindz reviewed Jun 4, 2026

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Comment thread wled00/bus_manager.cpp Outdated

netmindz reviewed Jun 4, 2026

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Comment thread wled00/bus_manager.cpp Outdated

HUB75 tiny bugfix

32412c9

ensure that BusHub75Matrix::getPixelColor() returns RGBW format, not RGBA. Currently busses.getPixelColor() is not used by the WLED core.

softhack007 mentioned this pull request Jun 4, 2026

HUB75: Some 2D effects missing pixel trails in v16.0 (Black Hole, Lissajous, Spaceships) #5664

Closed

Merge branch 'main' into hub75_4scan_bugfixes

53cbb15

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softhack007 removed hardware (Likely) Setup-specific issue, e.g. flickering LEDs Awaiting testing labels Jun 4, 2026

Merge branch 'main' into hub75_4scan_bugfixes

939c254

softhack007 added this to the 16.0.0 release + bugfixes milestone Jun 9, 2026

softhack007 self-assigned this Jun 19, 2026

Merge branch 'main' into hub75_4scan_bugfixes

51540c4

softhack007 added 2 commits June 29, 2026 19:07

move _isQuadScan up

efa5ab7

fix missing comma

0da10eb

softhack007 added the Awaiting testing label Jun 29, 2026

softhack007 marked this pull request as ready for review June 29, 2026 17:15

simplify logic for _isVirtual

b5934ef

softhack007 commented Jun 29, 2026

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softhack007 commented Jun 29, 2026

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Comment thread wled00/bus_manager.cpp Outdated

bugfixing

d77b3b7

* prevent using mxconfig.mx_height before it was set *untangle virtual / physical panel dimensions from _isVirtual

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softhack007 and others added 3 commits June 29, 2026 20:00

Use the clamped chain length when enabling virtual chaining.

fd3f36f

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

no exceptions - handle virtualDisp alloc error without crahing

b7527c2

fix endif comment

1c4c2e1

softhack007 requested review from DedeHai and netmindz June 29, 2026 18:16

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softhack007 removed the Awaiting testing label Jun 30, 2026

minor stuff

c862008

* comment update * put bool condition into brackets

DedeHai approved these changes Jun 30, 2026

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Comment thread wled00/bus_manager.cpp Outdated

revert FastLED-style RGB mask

8e6d214

fastled-slim does not need the " & 0x00FFFFFF" mask

softhack007 merged commit 301e962 into main Jun 30, 2026
56 checks passed

softhack007 deleted the hub75_4scan_bugfixes branch June 30, 2026 17:44

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Summary by CodeRabbit

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DedeHai commented Jun 4, 2026

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