usb_cdc_virtual_serial_port.py

try:
    import sys
    import serial
    import argparse
    import serial.tools.list_ports
except ImportError:
    sys.exit("""ImportError: You are probably missing some modules. Try 'pip install pyserial'""")
    
# VID and PID for AVR DU, must match values set in MCC
DU_VID = 0x04D8
DU_PID = 0x0B15

# Function for fetching virtual com-ports based on VID and PID
def GetSerialPort(vid, pid):
    serialPort = ""
    for port in serial.tools.list_ports.comports():
        if (port.vid == vid and port.pid == pid):
            serialPort = port.device
    return serialPort

def printHex(input):
    return ' '.join(f'{c:0>2X}' for c in input)

def main(serialPortNum):
    # Gets default device serial port if not given
    if "" == serialPortNum:
        serialPortNum = GetSerialPort(DU_VID, DU_PID)
    
    # Starts device serial communication if serial port exists, else throws error
    print("Opening serial communication...")
    if "" != serialPortNum:
        cdcSerial = serial.Serial(serialPortNum,115200,timeout=1)
    else:
        print("CDC Virtual Serial Port number error detected - Could not start serial communication")
        sys.exit("Error occurred")
    
    # An array containing the message "Welcome to the AVR DU experience! USB connectivity on a modern AVR." in decimal ASCI
    sentData = [87, 101, 108, 99, 111, 109, 101, 32, 116, 111, 32, 116, 104, 101, 32, 65, 86, 82, 32, 68, 85, 32, 101, 120, 112, 101, 114, 105, 101, 110, 99, 101, 33, 32, 85, 83, 66, 32, 99, 111, 110, 110, 101, 99, 116, 105, 118, 105, 116, 121, 32, 111, 110, 32, 97, 32, 109, 111, 100, 101, 114, 110, 32, 65, 86, 82, 46]
    sentDataSize = len(sentData)
    cdcSerial.write(sentData)
    print("Transmitting Data:")
    print(printHex(sentData))
    
    receivedData = cdcSerial.read(sentDataSize)
    print("Received Data:")
    print(receivedData)
    
    print("Closing the serial communication.")
    cdcSerial.close
    
if __name__ == '__main__':
    # Generate help and use messages
    parser = argparse.ArgumentParser(
    description='USB CDC Python example script for virtual serial port communication on AVR DU',
    epilog='Example: python usb_cdc_virtual_serial_port.py',
    formatter_class=argparse.RawTextHelpFormatter)
    parser.add_argument(
    '-s','--serialPortNum', help='device communication port, defaults to finding device based on VID and PID', default="")
    args = parser.parse_args()
    
    main(args.serialPortNum)