CODEWITHSUNDEEP
pythonserial-port
Jennifer
Jennifer

Reputation: 37

Cannot detect any serial ports with Python

I am trying to find the correct com port a device is connected to before being able to run the rest of the Python script.

I have tried using this:

    import serial.tools.list_ports
    ports = list(serial.tools.list_ports.comports())
    for p in ports:
        print p

And this:

    import wmi
    c = wmi.WMI()
    wql = "Select * From Win32_SerialPort"
    for item in c.query(wql):
        print item

And this: 

    def serial_ports():

    if sys.platform.startswith('win'):
        ports = ['COM%s' % (i + 1) for i in range(256)]
        print ports 
    elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
        # this excludes your current terminal "/dev/tty"
        ports = glob.glob('/dev/tty[A-Za-z]*')
    elif sys.platform.startswith('darwin'):
        ports = glob.glob('/dev/tty.*')
    else:
        raise EnvironmentError('Unsupported platform')

    result = []
    for port in ports:
        try:
            s = serial.Serial(port)
            s.close()
            result.append(port)
        except (OSError, serial.SerialException):
            pass
    return result

All of these methods are ones that I have found from other stack exchange posts; however, with both functions, when I try to print the list of com ports I get a blank list? Any help/insights would be greatly appreciated thanks in advance!

Upvotes: 2

Views: 1030

Answers (1)

dsgdfg
dsgdfg

Reputation: 1510

Like this :

import serial,os,sys,glob


def serial_ports():

    if sys.platform.startswith('win'):
        ports = ['COM%s' % (i + 1) for i in range(256)]
        print ports 
    elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
        # this excludes your current terminal "/dev/tty"
        ports = glob.glob('/dev/tty[A-Za-z]*')
    elif sys.platform.startswith('darwin'):
        ports = glob.glob('/dev/tty.*')
    else:
        raise EnvironmentError('Unsupported platform')

    result = []
    print ports
    for port in ports:
        try:
            s = serial.Serial(port,9600)
            s.close()
            result.append(port)
        except (OSError, serial.SerialException):
            pass
    return result

print serial_ports()

Never can open any serial port without speed (clock) definition.

On linux : run as root, normal user can't access /dev (Don't change permission cos name_space creating dynamically. Bad idea !).

Upvotes: 1

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