Can't set brightness in NeoPixel()

[LukeMoll]

import board
import neopixel

# Causes error
pixels = neopixel.NeoPixel(board.A15, 8, brightness=0.5) 

# works fine
pixels = neopixel.NeoPixel(board.A15, 8, brightness=1.0) 
pixels.brightness = 0.5 

Setting brightness to than 1.0 in NeoPixel() causes the following error:

Traceback (most recent call last):
  File "main.py", line 5, in <module>
  File "neopixel.py", line 131, in __init__
  File "adafruit_pypixelbuf.py", line 103, in __init__
  File "adafruit_pypixelbuf.py", line 187, in brightness
  File "adafruit_pypixelbuf.py", line 206, in show
  File "neopixel.py", line 167, in _transmit
AttributeError: 'NeoPixel' object has no attribute 'pin'

I believe this is attributed to self._transmit being called (referencing self.pin) by pypixelbuf as part of super().init, before self.pin is initialised on line 135.

Tested with Adafruit CircuitPython 5.3.0 on 2020-04-29; stm32f411ce-blackpill with STM32F411CE, CircuitPython bundle 5.x 20200526.

[tannewt]

@LukeMoll Would you mind creating a fix PR for this? I think you can either init the pin earlier or disable auto_write until everything is set.

[LukeMoll]

Sure, I can have a go at that sometime next week :)

[tannewt]

@LukeMoll Awesome! Thanks! Join our discord if you need any help (or just want to :-) ): https://adafru.it/discord

[FoamyGuy]

This code is working properly for me on a Neo Trellis M4 with 5.4.0.beta and Neo pixel library out of today's library bundle:

import board
import neopixel

pixels = neopixel.NeoPixel(board.NEOPIXEL, 32, brightness=0.05)
pixels[0] = (0,0,100)

while True:
    pass

I am not experiencing any crash or other issues from this code.

What device and version of Circuit Python are you using when you see this error?

[LukeMoll]

@FoamyGuy I mentioned at the bottom of my issue:

Tested with Adafruit CircuitPython 5.3.0 on 2020-04-29; stm32f411ce-blackpill with STM32F411CE, CircuitPython bundle 5.x 20200526.

I've got an ItsyBitsy M4 and Trinket M0 that I can try reproducing on later.

[FoamyGuy]

Ah, whoops. I missed that on the first read. Thank you. The STM32 port is somewhat newer. I wonder if this is actually a symptom of an issue with that port rather than the neopixel library.

I will test on a nrf52840 based device as well so we will cover all of the current main processor types between us.

[Al105]

Hi, I found same error when auto_write=True - could you verify this as well?

[evaherrada]

I actually ran into this testing someone's code from the forum today, the brightness wouldn't change when auto_write was enabled

[kevinjwalters]

I get this on 5.3.0 using 20200703 libs too.

Another issue from the forum which is likely to be this too: Adafruit Forums: Help needed! REALLY basic!).