import serial.tools.list_ports
import time
BAUD_RATE = 57600

def test_ports():
    print("Ports found: ")
    ports = serial.tools.list_ports.comports()
    
    for port in ports:
        print("{port.device}: {port.description} [manufacturer: {port.manufacturer}]".format(port=port))
    if (len(ports) == 0):
        print("No ports found. Make sure your board is plugged in and turned on?")
    print()

    for port in ports:
        
        test_port = input("test port '{port.device}'? (y/n/exit) ".format(port=port))
        
        while (test_port == "y"):
            
            try:
                ser = serial.Serial(port.device,BAUD_RATE, write_timeout=4)
                print("\twatch for a flashing green `TX` light")
                
                for i in range(10):
                    ser.write( bytes("Hello, World!", 'utf-8') )
                    time.sleep(0.5)
                
                print("Test completed\n")
            except Exception as e:
                print("Test failed with: {}\n".format(e))
            
            test_port = input("REPEAT test for '{port.device}'? (y/n/exit) ".format(port=port))
            
        if (test_port == "exit"):
            exit()

test_ports()