neopixel spi raspberry Problem Moderators: adafruit_support_bill, adafruit

[thebeater]

Hello together,

I have a problem to control SK6812 RGBW Strips with Raspberry python3 through neopixel_SPI.

When I start the application - the first led is getting red, but after one second all leds which are declared through NUM_PIXELS getting white.

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import time
import board
import neopixel
 
NUM_PIXELS = 12
PIXEL_ORDER = neopixel.GRB
COLORS = (0xFF0000, 0x00FF00, 0x0000FF)
DELAY = 1
 
spi = board.SPI()
 
pixels = neopixel.NeoPixel_SPI(spi,
                               NUM_PIXELS,
                               pixel_order=PIXEL_ORDER,
                               auto_write=False)
 
while True:
    pixels[0] = COLORS[0]
    pixels.show()
    time.sleep(DELAY)
    pixels[0] = COLORS[1]
    pixels.show()
    time.sleep(DELAY)

The used library is neopixel_spi, installed through this guide:
https://learn.adafruit.com/circuitpytho ... i?view=all

I did an upgrade of the neopixel library andbusdevice library through

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pip3 install --upgrade adafruit-circuitpython-neopixel

but the problem still exists.

Can anyone help me with this problem?

Thanks in advance,

[siddacious]

I'll forward this to someone who will know better than me; hold tight!

[danhalbert]

Hi, since you said this is an RGBW strip, trying changing `PIXEL_ORDER` to `neopixel.GRBW`.

[adafruit2]

hiya, please use the plain 'neopixel' library. spi neopixel is not as trustworthy!

[thebeater]

Hi,

the normal neopixel library is based on the pwm system or?
is the pipeline in this library also dma powered?
Can I send there also the neopixel bytes with 800kbit/s?

Thanks in advance,

[adafruit_support_carter]

Here's info on the other approach suggested:
https://learn.adafruit.com/neopixels-on ... thon-usage

But might be worth also making sure there's nothing odd going on with your hardware setup. Can you post a photo showing how everything is connected. What model Pi are you using? What specific NeoPixel product are you using?

[thebeater]

Hello,

I'm using GPIO18 directly and use Raspberry Pi 3 B Plus.
The Pixel is SK6812 RGBW.

[adafruit_support_carter]

If you are trying that with the NeoPixel_SPI class, that's not the hardware SPI line. See here:
https://learn.adafruit.com/circuitpytho ... wiring-3-5

If you are trying that with the kernel driver, see here:
https://learn.adafruit.com/neopixels-on ... -pi-wiring

[thaamike]

Hi,

I have connected raspberry pi 4 to WS2812 led's using pin gpio 10 (spi). After the first led is written correctly all the other leds go white. I noticed with my scope that the frequency drops from about 800kHz to 400kHz. Sometimes is happens after the 2nd write or 3rd. But the frequency just drops so that the leds see wrong information.

When is use the other GPIO's that are mentioned in the neopixel uber guide i have no problems at all. Only GPIO10 has issues.

Any idea how this could be fixed?

[adafruit_support_carter]

@thaamike Please start a new thread for your issue.