Neopixel crash with >75 pixels using ESP32 Core 3.0.x

[Nourbakhsh-Rad]

I am running into an issue where after upgrading the ESP32 package from 2.0.17 to 3.0.x, Neopixel sketches with an LED count of 76 or more get into a crash loop

I am using the Adafruit_NeoPixel 'simple.ino' sketch for testing

Board: ESP32 Dev Module (ESP32-devkitC-v4)
Hardware Configuration: ESP32 Dev Module
Version: v3.0.4
IDE Name: Arduino IDE 2.3.2
Operating System: Windows 10
Flash frequency: 80
PSRAM enabled: no
Upload speed: 921600

Note that, I am using the latest version of the Adafruit_NeoPixel library and the Arduino ESP32 core 3.0.4

when using ESP32 package 2.0.17 everything is ok
with ESP32 package 3.0.x and LED_COUNT <76 everything is also ok

Similar issue reported in #401 and #9903 and #9906, the full explanation about this problem is here

[imjustger]

I encountered the same issue. My project, which uses a XIAO ESP32S3 board running ESP32 2.0.17 by Espressif Systems, worked fine until I updated the firmware yesterday. Without noticing, I upgraded to Arduino’s 3.0.5 version for the board, which now causes my microcontroller to crash whenever the Neopixel library is invoked.”The microcontroller crashes and triggers a stack overflow error (ERROR A stack overflow in task loopTask has been detected.) when running even the most basic NeoPixel control sketches.

Steps to Reproduce:
1. Set up an LED strip (SK6812 RGBW) with the XIAO ESP32S3.
2. Install NeoPixel library version 3.0.5.
3. Upload a basic sketch controlling the LED strip (e.g., a simple color wipe).

Expected Behavior:

The LEDs should work without issue, and the system should remain stable.

Actual Behavior:

•	The ESP32S3 microcontroller experiences a stack overflow error, causing crashes.
•	The error is consistently reproducible with version 3.0.5.

Temporary Fix:

Rolling back to NeoPixel v2.0.17 resolves the issue entirely. With version 2.0.17, the microcontroller operates as expected, without crashing or showing any signs of instability.

Environment:

•	Board: XIAO ESP32S3
•	NeoPixel Library: v3.0.5 (issue), v2.0.17 (working)
•	Arduino IDE: 2.3.2
•	LED Strip: SK6812 RGBW

It seems that version 3.0.5 of the NeoPixel library has compatibility or memory management issues with the XIAO ESP32S3, specifically leading to a stack overflow. Please investigate the changes in v3.0.5 that might be causing this issue. I’m happy to provide additional details if needed.

[Nourbakhsh-Rad]

The problem seems to be with the esp32-hal-rmt library of the new ESP32 core (3.0.x)

[sanchosk]

For SK6812 LED strips with white leds, the library fails the same way after 56 LEDs.

[plin2]

Same problem here:

Arduino IDE 2.3.3

Chip is ESP32-D0WD-V3 (revision v3.1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz

Set of 4 WS2812B tiles with 8x8 pixels.

Tried several ESP32 boards (hardware as well as boards in Arduino).

8x8 works fine, anything like 16x8, 8x16, 16x6 crashes.

[k11o]

I've got same issue. And I dealed this with this forked library.

[plin2]

I went a completely different way. For what I need WLED is doing the job.