接着上一篇ESP8266-NodeMCU-闪灯实验的接线,我们调整一下代码,使LED灯的显示亮度发生变化。

参考代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
from machine import Pin,Timer,PWM
pwm =PWM(Pin(14),100) #create PWM object from a pin,and set frequency
polar = 0
duty = 0

def setLed(t): #create a variate,and change it between 0 and 1008
global duty,polar
if(polar == 0):
duty+=16
if(duty >= 1008):
polar = 1
else:
duty -= 16
if(duty <= 0):
polar = 0
pwm.duty(duty) #set duty of the PWM

tim = Timer(1) #create Timer object from Virtual timers with timer ID=1
tim.init(period=10,mode=Timer.PERIODIC, callback=setLed) #init Timer,Call the callback function with per second

try: #The catching
while True:
pass
except: #Capture anomaly, deinit Timer and PWM
tim.deinit()
pwm.deinit()