An Example of Automatic Triggering of Serial Port by python

Recently in an python tool need to achieve the serial port automatic trigger work function, before only in winform above the implementation, today use python try. Here's a brief note:

First, implement an Button with wxpython, and click the event binding function OnButtonAutoStopAll

self.button_autoStopAll = wx.Button(id=wxID_FRAME1BUTTONAUTOSTARTALL, label=u'AUTO STOP ALL',
       name='button_autoStop', parent=self.staticBox_common, pos=wx.Point(8, 284),
       size=wx.Size(180, 80), style=0)
    self.button_autoStopAll.SetFont(wx.Font(24, wx.SWISS, wx.NORMAL, wx.BOLD, False,
       u'Agency FB'))
    self.button_autoStopAll.Bind(wx.EVT_BUTTON, self.OnButtonAutoStopAll,
       id=wxID_FRAME1BUTTONAUTOSTARTALL)

Then there is ComboBox control to automatically load the current serial port name when clicking drop-down

 self.combox = wx.ComboBox(self, -1, pos=wx.Point(10,100), size=wx.Size(100,50), 
     style=wx.CB_READONLY) # Serial port combox
 self.combox.Bind(wx.EVT_COMBOBOX_DROPDOWN, self.evt_combox_dropdown)

Drop-down menu event function

def evt_combox_dropdown(self, event):
    print 'combox%d dropdown'%self.sta_num
    serial_list = list(serial.tools.list_ports.comports())
    if serial_list: # Determine whether it is null 
      portName_list = []
  # Conversion serial handle For port name
      for i in range(0, len(serial_list)):
        portname = list(serial_list[i])
        portName_list.append(str(portname[0]))
      print portName_list
    
    self.combox.SetItems(portName_list)

Then get down to business, which is triggered according to DSR signal.

# Serial port automatically triggers detection thread 
class Job(threading.Thread):
  ...
 
  def run(self):
    while self.__running.isSet():
      self.__flag.wait()       #  For True Return immediately when ,  For False Block until the internal ID bit is True Back 
      print "into job function"
	  i=0
      isOpen = serial_isOpen(i)
      if serial_list[i]!=1 and isOpen:
        now_dsr = serial_list[i].getDSR()
        if now_dsr != last_dsr[i]:
          last_dsr[i] = now_dsr
          print 'dsr level changed to %d'%now_dsr
          if now_dsr == True:
            if thread_list[i] != 1:
              if ~thread_list[i].is_alive():
                serial_Open(0, False)
                #do something
            else:
              serial_Open(0, False)
              #do something
        break
      time.sleep(1)
 
  ...

That is, every time the DSR signal is set low, it triggers the operation