Random flickers after updating to 0.15.4 (8266 bit-bang driver)

[coltography]

What happened?

I have an esp8266 (nodemcu) with 350 WS281B on GPIO15. Powered by 10A 5V PSU. It's worked without issue for over 2~ years and I've updated it any time there's one available. Updating to 0.15.4 made it randomly flicker with no real cause, nothing else changed. I originally had it on GPIO2 and thought maybe there was a problem with this, so changed to GPIO15 and the issue persisted.

Downgraded to 0.15.3 and the random flickers are gone. I checked Home Assistant to see if the device was rebooting or going unavailable during these flickers but it wasn't.

To Reproduce Bug

Not sure. Power on device and allow it to run.

Expected Behavior

No flickers

Install Method

Binary from WLED.me

What version of WLED?

0.15.4

Which microcontroller/board are you seeing the problem on?

ESP8266

Relevant log/trace output

Anything else?

No response

Code of Conduct

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

[DedeHai]

That is very strange as there was no change to code that touches anything regarding LED outputs on the ESP8266.
How often do you see the flickering and what does it look like?
What levelshifter are you using and how long and how tidy are the data wires?

[kbickar]

I'm also seeing this issue. I don't have a level shifter, the controller is about 1 inch from the first LED, and it didn't happen before the update

[DedeHai]

WLED can not compensate for insufficient hardware (yet) so your best option is to just stay on 0.15.3

[kbickar]

That's definitely an odd way to state that the recent minor update made it more bloated and less efficient.

Everyone knows the esp8266 is a very capable board that can handle most usages (as it has for years) . Saying it's "insufficient hardware" is a lame excuse. If support is being dropped, the project should be forked for a new major version while the compatible version continues

[DedeHai]

like I said, there was no change to code that affects LED output and by insufficient hardware I did not mean the ESP8266.
I have done extensive investigation on flickering and only very few instances are related to software bugs, the vast majority is systems that are not built properly and are just at the brink of being unstable and the slightest change in timing (we are talking a handful of nanoseconds) can tip them over into the flickering side.
It is not something that can currently be solved.

[kbickar]

I have around 150 LEDs so nothing major (I have another one that's not updated with over 600 LEDs).

There are multiple reports of this with this update, so this is definitely a regression from the previous version. Is there something I can check to see if it's pushing the resources?

[DedeHai]

We do get flicker reports on every update - even from 15.2 to 15.3 where absolutely nothing changed in code (it was just a re-release due to some complications) so like I said, setups that are just barely stable (wiring, shifter, supply etc. many factors play a role) can experience this from update to update. The fix is to either not update or fix your setup so it is stable.
I do have a long-term fix by writing our own LED driver library from scratch that will allow more fine-tuning but that is not something that will be finished and ready soon.