Since FW 0.15.1 an LED strip is flashing

[hardl1]

What happened?

Two LED strips WS2812B with 300 LEDs are connected to GPO 16 + 02 on WLED and work without problems.

To Reproduce Bug

It worked fine with firmware 0.15.0, but since 0.15.1, a stripe has been flashing every 10-30 seconds.
After resetting to 0.15.0, the flashing stopped.

Expected Behavior

No blinking, just unilight.

Install Method

Binary from WLED.me

What version of WLED?

WLED 0.15.1 (Build 2507300)

Which microcontroller/board are you seeing the problem on?

ESP32

Relevant log/trace output

Anything else?

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[blazoncek]

English, please.

[hardl1]

Sorry, chanced.

…

Am 02.08.2025 um 11:59 schrieb Blaž Kristan ***@***.***>: blazoncek left a comment (wled/WLED#4805) <#4805 (comment)> English, please. — Reply to this email directly, view it on GitHub <#4805 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AJHFRQB7YZ676OI34G5RCML3LSDZTAVCNFSM6AAAAACC6QPPEOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCNBWGQYDEOBXGQ>. You are receiving this because you authored the thread.

[blazoncek]

Did you enable "Use parallel I2S"? If not, do it, it may help.

[hardl1]

Unfortunately I can't find this setting.

[BerendWouters]

I've got the same issue. I've got 4 segments, and (I think) two of them are flickering.
I2S parallel is enabled (@hardl1 you can find this setting in Config > LED Preferences, just below the memory usage)

Reverting to 0.15.0 "fixes" the issue.

[hardl1]

@BerendWouters, not by me...

[BerendWouters]

@BerendWouters, not by me...

It's introduced in 0.15.1, I think :)

[hardl1]

That's right, I updated again to 0.15.1, the field is there, it's enabled, but it still flashes.

[lost-hope]

What is that flicker like? just single LEDs or the whole strip
and what is you hardware setup? ESP32 with or without levelshifter (which shifter).

[hardl1]

The entire strip is flashing. I can't comment on the level shifter, as I bought the device ready-made.

[willmmiles]

Could anyone experiencing this issue please post their cfg.json file? I haven't been able to replicate it locally, but I have a suspicion it might be related to exact LED strip lengths.

[hardl1]

How do I do that?
I'm back on 0.15.0, but I can change that.