PySerial DTR and RTS Manipulation

Another application using (Python) PyQt and PySerial: a simple serial port LED blinker program.

two LEDs connected to DTR and RTS of a COM port (pins 4 and 7 of DB9):

simple python py script:

 import sys, serial  
 from PyQt4.QtGui import *  
 from PyQt4.QtCore import *  
   
 class MyForm(QDialog):  
   def __init__(self, parent = None):  
     super(MyForm, self).__init__(parent)  
     self.setWindowTitle('PySerial DTR and RTS Manipulation')  
     self.setMinimumSize(300, 100)  
     # widgets  
     DTRlabel, RTSlabel = QLabel(), QLabel()  
     self.DTRbutton = QPushButton('set to Logic "True"')  
     self.RTSbutton = QPushButton('set to Logic "True"')  
     self.DTRcheckbox = QCheckBox('continuous toggle')  
     self.RTScheckbox = QCheckBox('continuous toggle')  
     # layout  
     layout = QGridLayout()  
     layout.addWidget(DTRlabel, 0, 0)  
     layout.addWidget(RTSlabel, 0, 1)  
     layout.addWidget(self.DTRbutton, 1, 0)  
     layout.addWidget(self.RTSbutton, 1, 1)  
     layout.addWidget(self.DTRcheckbox, 2, 0)  
     layout.addWidget(self.RTScheckbox, 2, 1)  
     self.setLayout(layout)  
     # serial port  
     self.port = serial.Serial('COM1')  
     DTRlabel.setText("<font size = 5 color = darkred><b> " +self.port.name + " DTR pin:</b></font>")  
     RTSlabel.setText("<font size = 5 color = darkred><b> " +self.port.name + " RTS pin:</b></font>")  
     self.DTRlogic, self.RTSlogic = False, False  
     self.port.setDTR(self.DTRlogic)  
     self.port.setRTS(self.RTSlogic)  
     # events  
     self.connect(self.DTRbutton, SIGNAL('clicked()'), self.toggleDTR)  
     self.connect(self.RTSbutton, SIGNAL('clicked()'), self.toggleRTS)  
     self.DTRtimer , self.RTStimer = QTimer(), QTimer()  
     self.connect(self.DTRtimer, SIGNAL('timeout()'), self.eventDTRtimer)  
     self.DTRtimer.start(250) # in milliseconds  
     self.connect(self.RTStimer, SIGNAL('timeout()'), self.eventRTStimer)  
     self.RTStimer.start(100) # in milliseconds  
     
   def toggleDTR(self):  
     self.DTRbutton.setText('set to Logic "' + str(self.DTRlogic) + '"')  
     self.DTRlogic = not self.DTRlogic # invert logic  
     self.port.setDTR(self.DTRlogic)  
   def toggleRTS(self):  
     self.RTSbutton.setText('set to Logic "' + str(self.RTSlogic) + '"')  
     self.RTSlogic = not self.RTSlogic # invert logic  
     self.port.setRTS(self.RTSlogic)  
   def eventDTRtimer(self):  
     if self.DTRcheckbox.isChecked():  
       self.toggleDTR()  
   def eventRTStimer(self):  
     if self.RTScheckbox.isChecked():  
       self.toggleRTS()  
       
 if __name__ == '__main__':  
   app = QApplication(sys.argv)  
   form = MyForm()  
   form.show()  
   sys.exit(app.exec_())  
   

demo:

*the 'blink' rate depends on QTimer timeout period

forum link: serial port LED blinker