neopixel behaves oddly on esp32-s3-devkitm-1

[jepler]

CircuitPython version

Adafruit CircuitPython 7.2.0-alpha.0-38-g121b22b0c-dirty on 2021-12-07; ESP32-S3-DevKitC-1 with ESP32S3

Code/REPL

# none

Behavior

The initial 3 flashes of the onboard neopixel work, but then after that the LED sometimes blinks random colors.

Description

No response

Additional information

This problem affects the 1 ESP32-S3-DevKitM-1 I have, but neither of the ESP32S3-DevKitC-1 (both with PSRAM) that I have.

The LED attachment is the same in both schematics, with no pull up/down to ensure the neopixel's input doesn't fluctuate. However, this seems to be typical of how neopixels are wired.

If the GPIO is placed in InputEnable mode (without pull up or down, i.e., just create a DigitalinOut object for the pin), it happens to stop the flickering. But since the neopixel pin is usually freed by the supervisor between color settings, it is normally placed in input disabled / output disabled / no pulls mode.

It's possible that this is just specific to the board and other boards are fine, however, I only had one board to test.

Affected module on the left:

PXL_20211207_192903939.mp4.2.mp4