https://tutorials-raspberrypi.com/connect-control-raspberry-pi-ws2812-rgb-led-strips/
4b配置过程
硬件连接
这个图只是个示意图,如果灯比较少直接树莓派5V供电
如果灯比较多,可以参看上图的外接供电
VCC-5v
gnd-gnd
vin-18引脚
环境配置
sudo apt-get update sudo apt-get install gcc make build-essential python-dev git scons swig
下载源码
git clone https://github.com/jgarff/rpi_ws281x
编译
cd rpi_ws281x/ sudo scons
编译python版本
cd python sudo python setup.py build sudo python setup.py install
examples文件夹下面是使用样例
标准测试样例
执行之前需要将编译的库拷贝过来 或者 运行程序直接添加环境
拷贝到测试样例
运行代码 必须从命令行以sudo 运行 否则报错
原理例成被我改了 未来使用必然配合别的程序,然而彩虹灯这样的效果需要占据一个线程
因此重新封装成一个类,并加入了多进程单独控制灯(线程本质上在树莓派还是一个线程)
如何使用
1新建一个工程,拷贝一个依赖文件到工程同目录
2把这个代码创建一个文件LED_Class放在同工程
详见后面LED_Class.py 文件
3要使用的test.py代码加入这个类
from LED_Class import LED
一定要从命令行 sudo 启动 text.py
from LED_Class import LED import time led_use=LED() led_use.process_test() while 1: print('这是主进程!') time.sleep(2.0)#延迟2秒
LED_Class.py 文件
#!/usr/bin/env python3 import time from neopixel import * import argparse from multiprocessing import Process class LED(object): def __init__(self): LED_COUNT = 8 # 灯的数目 LED_PIN = 18 # pwm管教口 18引脚 树莓派. #LED_PIN = 10 # GPIO pin connected to the pixels (10 uses SPI /dev/spidev0.0). 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 # 工艺参数 #parser = argparse.ArgumentParser() #parser.add_argument('-c', '--clear', action='store_true', help='clear the display on exit') #args = parser.parse_args() # 创建LED控制对象 self.strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL) self.strip.begin() print('LED初始化成功') #功能一-逐个变色- # colorWipe(self.strip, Color(255, 0, 0)) # Red wipe # 所有灯逐个变成红色 def colorWipe(self,color, wait_ms=50): """Wipe color across display a pixel at a time.""" for i in range(self.strip.numPixels()): self.strip.setPixelColor(i, color) self.strip.show() time.sleep(wait_ms/1000.0) #功能二-交替闪烁 # theaterChase(self.strip, Color(127, 127, 127)) # White # 白色交替闪烁 def theaterChase(self, color, wait_ms=50, iterations=10): """Movie theater light style chaser animation.""" for j in range(iterations): for q in range(3): for i in range(0, self.strip.numPixels(), 3): self.strip.setPixelColor(i+q, color) self.strip.show() time.sleep(wait_ms/1000.0) for i in range(0, self.strip.numPixels(), 3): self.strip.setPixelColor(i+q, 0) # 支撑函数 def wheel(self,pos): """Generate rainbow colors across 0-255 positions.""" if pos < 85: return Color(pos * 3, 255 - pos * 3, 0) elif pos < 170: pos -= 85 return Color(255 - pos * 3, 0, pos * 3) else: pos -= 170 return Color(0, pos * 3, 255 - pos * 3) #功能三-彩虹色整体统一柔和渐变-每个灯颜色同一时间相同 def rainbow(self, wait_ms=20, iterations=1): """Draw rainbow that fades across all pixels at once.""" for j in range(256*iterations): for i in range(self.strip.numPixels()): self.strip.setPixelColor(i, self.wheel((i+j) & 255)) self.strip.show() time.sleep(wait_ms/1000.0) #功能四-彩虹色每一个灯各自柔和渐变-每个灯颜色同一时间不同 def rainbowCycle(self, wait_ms=20, iterations=5): """Draw rainbow that uniformly distributes itself across all pixels.""" for j in range(256*iterations): for i in range(self.strip.numPixels()): self.strip.setPixelColor(i, self.wheel((int(i * 256 / self.strip.numPixels()) + j) & 255)) self.strip.show() time.sleep(wait_ms/1000.0) #功能五-彩虹色统一闪烁流动变色-每个灯颜色同一时间相同 def theaterChaseRainbow(self,wait_ms=50): """Rainbow movie theater light style chaser animation.""" for j in range(256): for q in range(3): for i in range(0, self.strip.numPixels(), 3): self.strip.setPixelColor(i+q, self.wheel((i+j) % 255)) self.strip.show() time.sleep(wait_ms/1000.0) for i in range(0, self.strip.numPixels(), 3): self.strip.setPixelColor(i+q, 0) #单进程全部函数测试 def test(self): print ('Color wipe animations.') self.colorWipe( Color(155, 0, 0)) # Red wipe self.colorWipe( Color(0, 255, 0)) # Blue wipe self.colorWipe( Color(0, 0, 255)) # Green wipe print ('Theater chase animations.') self.theaterChase( Color(127, 127, 127)) # White theater chase self.theaterChase( Color(127, 0, 0)) # Red theater chase self.theaterChase(Color( 0, 0, 127)) # Blue theater chase print ('Rainbow animations.') self.rainbow() self.rainbowCycle() self.theaterChaseRainbow() #多进程全部函数测试 def process_test(self): print('process_begin') p= Process(target=self.test) p.deamon=True p.start() print('process_end') #----------------------------- #LED函数初始化 #led_use=LED() #1单个函数测试 #led_use.colorWipe(Color(100, 0, 0)) #2单进程全部函数测试 #led_use.test() #3多进程全部函数测试 ''' led_use.process_test() while 1: print('这是主进程!') time.sleep(2.0)#延迟2秒 '''