try: whileTrue: # 电流从小到大,LED由暗到亮 for i in xrange(0, 101, 1): # 更改占空比(电流大小), pwm.ChangeDutyCycle(i) time.sleep(.02) # 再让电流从大到小,LED由亮变暗 for i in xrange(100, -1, -1): pwm.ChangeDutyCycle(i) time.sleep(.02)
import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BOARD) channels = [7,11,13,15] p = [0for x in range(4)] for ch in channels: GPIO.setup(ch, GPIO.OUT) for i in range(4): p[i] = GPIO.PWM(channels[i], 50) #频率设为50Hz p[i].start(0) #0是占空比
try: whileTrue: for ch in range(4): for dc in range(0, 101, 1): p[ch].ChangeDutyCycle(dc) #更改占空比 time.sleep(0.005) for dc in range(100, -1, -1): p[ch].ChangeDutyCycle(dc) time.sleep(0.005) except KeyboardInterrupt: gpio.cleanup() print"All Cleanup!"