树莓派gpio控制led闪烁频率

#!/usr/bin/env python
# coding: utf-8

import sys
reload(sys)
sys.setdefaultencoding('utf-8')

import time
import RPi.GPIO as gpio

gpio.setmode(gpio.BCM)

pin = 14

gpio.setup(pin, gpio.OUT)
pwm = gpio.PWM(pin, 50)
pwm.start(0)
try:
while True:
for dc in range(0, 101, 5):
pwm.ChangeDutyCycle(dc)
time.sleep(0.05)
for dc in range(100, -1, -5):
pwm.ChangeDutyCycle(dc)
time.sleep(0.05)
except KeyboardInterrupt:
pass

pwm.stop()
gpio.cleanup()