问题：关闭端口后，python 仍然读取来自 arduino 的串行数据。串口无法关闭

Posted 2023-02-23

【中文标题】问题：关闭端口后，python 仍然读取来自 arduino 的串行数据。串口无法关闭

【英文标题】：Problem: The python still reads the serial data coming from arduino after closing its port. Serial port cannot be closed

【发布时间】：2018-09-15 20:07:32

【问题描述】：

我是 tkinter 的新手，使用 python 3.4。我正在使用***窗口开发 GUI，并从 Arduino 获取串行数据。这里唯一的问题是，每当从“class PETwithSC”中单击“home”按钮时，python 仍然会读取 StartPage 类中的数据并关闭 GUI。单击主页按钮后，我需要关闭串行端口。请帮忙。谢谢！

这是代码

    from tkinter import *
    import serial
    import time

    class StartPage() 
        def __init__(self,master)
             self.master = master
             self.master attributes('-fullscreen','true') 

             self.button = Button(self.master, command=self.pageOne)
             self.button.pack() 

        def pageOne(self)
             self.master.withdraw()
             self.pick = Toplevel(self.master)
             self.game = PETwithSC(sef.pick)

    class PETwithSC()
        def __init__(self,master)
             self.master = master
             self.master attributes('-fullscreen','true')

             ###### Home button
             self.button = Button(self.master, command=self.home)
             self.button.pack()

             self.data = StringVar()
             self.label = Label(self.master, textvariable = self.data)
             self.label.pack()
             self.master.after(1000,self.serial)

        def serial(self)
             self.ser = serial.Serial("/dev/ttyACM0",9600,timeout=0.1)
             self.ser.write(b'1') ##commanding the arduino to read the smartcard info
             self.info = self.ser.readline()
             self.data.set(self.info)
             self.master.after(1000,self.serial)
             print (A)

        def home(self)
             self.ser.close()
             self.master.withdraw()
             self.pick = Toplevel(self.master)
             self.game = StartPage(sef.pick)

    if __name__ == "__main__":
        app = Tk()
        myGUI = StartPage(app)
        app.mainloop

【参考方案1】：

因为self.serial()在循环运行：self.master.after(1000, self.serial)，而且每次都打开串口：self.ser = serial.Serial("/dev/ttyACM0",9600,timeout=0.1)，只是关闭了串口，self.master.withdraw()不会停止下一次运行self.serial从再次打开它。尝试在每次使用后关闭端口：

def serial(self)
         self.ser = serial.Serial("/dev/ttyACM0",9600,timeout=0.1)
         self.ser.write(b'1') ##commanding the arduino to read the smartcard info
         self.info = self.ser.readline()
         self.ser.close()                   #closing here
         self.data.set(self.info)
         self.master.after(1000,self.serial)
         print (A)

并从self.home() 中删除它：

def home(self)
         self.master.withdraw()            #rather than here
         self.pick = Toplevel(self.master)
         self.game = StartPage(sef.pick)

另外，错字：

self.game = PETwithSC(sef.pick)

应该是：

self.game = PETwithSC(self.pick)

希望对你有帮助