MicroPython ESP32外部中断使用示例

Posted 2022-09-06 perseverance52

【MicroPython ESP32】外部中断使用示例

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• ✨本案例基于Thonny平台开发。✨

📌ESP32外部中断相关函数在machine模块中

-🌿 通过Thonny平台，Shell调试窗口查询相关函数：

>>> import machine
>>> help(machine)

📖中断相关函数

• 📑state = machine.disable_irq(): 禁用中断
• 📑machine.enable_irq(state):启用中断

⛳中断触发回调示例

import machine
import time

led=machine.Pin(2,machine.Pin.OUT)
sw= machine.Pin(0,machine.Pin.IN)
def blink(num,t_on,t_off,msg):
    counter =0
    while (counter <num):        
        led.on()
        time.sleep(t_on)
        led.off()
        counter +=1
        time.sleep(t_off)
        counter +=1
    print(msg)
    
def call_back(pin):# 中断回调函数，这里的形参默认为`pin`中断引脚，必须要有
    print(pin)# 中断引脚
    print(int(str(pin)[4:-1]))# 提取中断引脚号
    blink(6,0.5,0.6,'hello world')
    
 # 上升沿或下降沿中断   
sw.irq(trigger=machine.Pin.IRQ_FALLING | machine.Pin.IRQ_RISING,handler =call_back)

🎆为防止中断来时重复执行相关业务代码，可以将想要执行的业务代码放到主函数当中，中断回调函数当中只设定标志位。在Micropython当中，在执行回调函数时关闭中断，然后执行完毕后再开启中断，如果回调函数中要执行的业务代码时间比较长，在此过程中，容易触发看门狗中断，从而导致重启，所以只能将代码放到主函数当中来执行。

• 🧾示例代码

import machine
import time
from machine import WDT

led=machine.Pin(2,machine.Pin.OUT)
sw= machine.Pin(12,machine.Pin.IN)
Tri = 0
def blink(num,t_on,t_off,msg):
    counter =0
    while (counter <num):        
        led.on()
        time.sleep(t_on)
        led.off()
        counter +=1
        time.sleep(t_off)
        counter +=1
    print(msg)
def call_back(pin):
    global Tri
    print(pin)
#     state = machine.disable_irq()#禁用
    print(int(str(pin)[4:-1]))
    Tri =  1
#     machine.enable_irq(state)
    
sw.irq(trigger=machine.Pin.IRQ_FALLING | machine.Pin.IRQ_RISING,handler =call_back)# 上升沿或和下降沿都可以触发中断

        
# if __name__=='__main__':
while 1:
    if(Tri ==1):        
        blink(6,0.5,0.6,'hello world')
        Tri =0
    else:
        led.off()
    

🎄中断计数器示例

import machine
interruptCounter = 0#与主程序通信
totalInterruptsCounter = 0#计算中断事件次数
def callback(pin):#定义回调函数    
    global interruptCounter#声明为全局变量
    interruptCounter = interruptCounter+1
    
p12 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP)#引脚编号、引脚模式下降沿以及是否存在相关拉电阻
p12.irq(trigger=machine.Pin.IRQ_FALLING, handler=callback)#触发中断，回调模式
while True:
  if interruptCounter>0:
    state = machine.disable_irq()#禁用计数器
    interruptCounter = interruptCounter-1
    machine.enable_irq(state)#重新启动计数器
    totalInterruptsCounter = totalInterruptsCounter+1
    print("Interrupt has occurred: " + str(totalInterruptsCounter))