32×64 HUB75 panel stays off or shows scrambled output with Adafruit HAT (SM16380SC)

1

Hardware Setup

  • Raspberry Pi 3B+
  • Adafruit RGB Matrix + Real Time Clock HAT
  • HUB75 32×64 LED panel (non-standard, mixed-chip variant)
  • Ribbon cable (HAT → panel)
  • Power: LRS-100-5 Meanwell feeding the HAT, Pi powered through the HAT

Panel ICs observed:

  • SM16380SC (LED driver)
  • RUC7258D (row/scan driver)
  • DP245D (timing/buffer IC)

Software Environment

  • OS: Raspberry Pi OS Bookworm
  • Library: hzeller/rpi-rgb-led-matrix (latest pull)
  • Demo command used:
    sudo ./demo --led-gpio-mapping=adafruit-hat --led-rows=32 --led-cols=64 -D 0

Issue Description

  • Running the demo initially produces no output.
  • If the HUB75 ribbon is disconnected, some LEDs flicker randomly.
  • Reconnecting makes the matrix react to commands, but the display is scrambled: animations distort, colors are wrong, and movement looks erratic.

This behavior resembles what others have seen with panels that need special initialization for unsupported driver ICs.

Steps Already Tried

  • Disabled onboard audio in config.txt (dtparam=audio=off).
  • Tested both --led-gpio-mapping=adafruit-hat and the default mapping.
  • Verified ribbon cable orientation (pin 1 → pin 1).
  • Ran demos with --led-no-hardware-pulse (result: flicker, still scrambled).
  • Checked power stability from the LRS-100-5; Pi is powered through the HAT.
  • Tried --led-panel-type=FM6126A and --led-panel-type=FM6127 (incompatible).
  • Tested the FM6126 reset script (resetmatrix.py), no effect on this SM16380-based panel.

Observations

  • Random flicker with the ribbon detached is consistent with floating inputs.
  • With the ribbon connected, the panel shows activity but outputs are garbled, suggesting the ICs aren’t initialized correctly.
  • The progression (no output → flicker → scrambled) aligns with known cases of unsupported chips.

Request for Help

This panel uses SM16380, RUC7258D, and DP245D ICs, and doesn’t respond to existing --led-panel-type options.

  • Has anyone managed to drive SM16380-based panels with this library?
  • Is there a known init/reset sequence for these chips?
  • Would adapting the library or writing a custom init script be the way forward?

References

2

gives a link to Led_drivers · board707/DMD_STM32 Wiki · GitHub

and it says SM16380 is SM-PWM, which will not work with and library that does pixel pushing line by line along with PWM refresh

3

No

See this: