用树莓派实现RGB LED的颜色控制——Python版本

电路连接方式请参考另一篇博文：【用树莓派实现RGB LED的颜色控制——C语言版本】

Python代码：

#!/usr/bin/env python
#*********************************************************
#	File Name ：rgb.py	
#	Author    ：Jason Dai
#	Date      : 2015/02/04
#*********************************************************
import RPi.GPIO as GPIO
import time

colors = [0xFF0000, 0x00FF00, 0x0000FF, 0xFFFF00, 0xFF00FF, 0x00FFFF, 0xFFFFFF, 0x9400D3]
pins = {'pin_R':11, 'pin_G':12, 'pin_B':13}  # pins is a dict

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'], 5000)

p_R.start(100)      # Initial duty Cycle = 100(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 setColor(col):   # For example : col = 0x112233
	R_val = (col & 0xFF0000) >> 16
	G_val = (col & 0x00FF00) >> 8
	B_val = (col & 0x0000FF) >> 0
	
	R_val = map(R_val, 0, 255, 0, 100)   # change a num(0~255) to 0~100.
	G_val = map(G_val, 0, 255, 0, 100)
	B_val = map(B_val, 0, 255, 0, 100)
	
	p_R.ChangeDutyCycle(100 - R_val)     # Change duty cycle
	p_G.ChangeDutyCycle(100 - G_val)
	p_B.ChangeDutyCycle(100 - B_val)

try:
	while True:
		for col in colors:
			setColor(col)
			time.sleep(0.5)
except KeyboardInterrupt:
	p_R.stop()
	p_G.stop()
	p_B.stop()
	for i in pins:
		GPIO.output(pins[i], GPIO.HIGH)    # Turn off all leds
	GPIO.cleanup()

运行程序：

python rgb.py