用树莓派4b，写的接线没问题，网上的代码，但是自己在学习的时候发现下面的代码亮不了，help！
```python
import time
from rpi_ws281x import PixelStrip, Color
LED_COUNT = 30 # LED灯的个数
LED_PIN = 18 # DI端接GPIO18
# 以下可以不用改
LED_FREQ_HZ = 800000 # LED signal frequency in hertz (usually 800khz)
LED_DMA = 10 # DMA channel to use for generating signal (try 10)
LED_BRIGHTNESS = 255 # Set to 0 for darkest and 255 for brightest
LED_INVERT = False # True to invert the signal (when using NPN transistor level shift)
LED_CHANNEL = 0 # set to '1' for GPIOs 13, 19, 41, 45 or 53
strip = PixelStrip(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_CHANNEL)
strip.begin()
strip.setPixelColor(1, Color(255, 255, 0))
strip.show()
