树莓派学习第一天：读懂rgb小灯

拿到树莓派，今天算是第一次读完一个树莓派的朋友python程序。官方的讲解实在。。。无语。
另附一个，输入法的切换是ctrl+space
先附一个完整代码，可以直接执行。在代码里几乎每行都有注释了

import RPi.GPIO as GPIO
import time

#colors = [0xFF0000, 0x00FF00, 0x0000FF, 0xFFFF00, 0xFF00FF, 0x00FFFF,0x112233]
colors=[0x12345678,0x223344,0x445566]
R = 11
G = 12
B = 13

def setup(Rpin, Gpin, Bpin):
	#初始化函数
    global pins
    global p_R, p_G, p_B
    pins = {'pin_R': R, 'pin_G': Gpin, 'pin_B': Bpin}
    GPIO.setmode(GPIO.BOARD)       # Numbers GPIOs by physical location
    for i in pins:
        GPIO.setup(pins[i], GPIO.OUT)   # Set pins' mode is output
        GPIO.output(pins[i], GPIO.HIGH) # Set pins to high(+3.3V) to off led
    
    p_R = GPIO.PWM(pins['pin_R'], 2000)  # set Frequece to 2KHz
    p_G = GPIO.PWM(pins['pin_G'], 2000)
    p_B = GPIO.PWM(pins['pin_B'], 2000)
    
    p_R.start(100)      # Initial duty Cycle = 0(leds off)
    p_G.start(100)
    p_B.start(100)

def map(x, in_min, in_max, out_min, out_max):# 将一个数从一个区间线性映射到另一个区间，比如将0~100之间的一个数映射到0~255之间
    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min

def off():
    for i in pins:
        GPIO.output(pins[i], GPIO.LOW)    # Turn off all leds

def setColor(col):   # For example : col = 0x112233
	#将一个32位二进制数字，提取出来对应的八位数字，载右移一定位置，得到一个0到255的数据
    R_val = (col & 0xff0000) >> 16
    G_val = (col & 0x00ff00) >> 8
    B_val = (col & 0x0000ff) >> 0
	#再映射到0到100
    R_val = map(R_val, 0, 255, 0, 100)
    G_val = map(G_val, 0, 255, 0, 100)
    B_val = map(B_val, 0, 255, 0, 100)
    #更改对应管脚输出（pwm输出）
    p_R.ChangeDutyCycle(100-R_val)     # Change duty cycle
    p_G.ChangeDutyCycle(100-G_val)
    p_B.ChangeDutyCycle(100-B_val)

def loop():
    while True:
        for col in colors:
            setColor(col)
            time.sleep(0.05)

def destroy():
    p_R.stop()
    p_G.stop()
    p_B.stop()
    off()
    GPIO.cleanup()

if __name__ == "__main__":
    try:
        setup(R, G, B)
        print(pins['pin_R'])
        loop()
    except KeyboardInterrupt:
        destroy()