# srv_util_01_v164.py
    # LX-824HV Testing v1.4  tlfong01 2020sep20hkt1159 
    
    # Contents
    
    # Serial UART LoopBack Program v0.62 (Minimal)
    # Serial UART LoopBack Program v0.98 (Multiple ports USB and on board UYART Ports)
    # HiWonder serial bus servo LX-824HV LewanSoul command testing (2020sep15)
    
    # Serial UART LoopBack Program v0.99 - https://penzu.com/p/f2cb232e
    # serial_loopback_test_v062.py tlfong01 2020jun03hkt1447
    # Rpi4B buster (r2020feb13), python 3.7.3 (r2019dec20), thonny v3.2.7 (r2020jan22)
    
    from   time import sleep
    import serial
    
    serialPort0 = serial.Serial(port = '/dev/serial0',
            baudrate = 9600,
            parity = serial.PARITY_NONE,
            stopbits = serial.STOPBITS_ONE,
            bytesize = serial.EIGHTBITS,
            timeout= 1)
    
    def setSerialPortBaudRate(serialPort, baudrate):                                                                                         
        print('   Begin setSerialPortBaudRate(), ...')
        print('     Serial port =', (serialPort0.name + ','), 'Buad rate =', baudrate)
        serialPort.baudrate = baudrate
        print('   End   setSerialPortBaudRate(), ...')
        print('')
        return
    
    def serialPortWriteBytes(serialPort, writeBytes):
        serialPort.write(writeBytes)
        return
    
    def serialPortReadBytes(serialPort, maxBytesLength):
        readBytes = serialPort.read(maxBytesLength)
        return readBytes
    
    def serialPortWriteWaitReadBytes(serialPort, writeBytes, maxBytesLength, waitSeconds):
        serialPort.flushInput()
        serialPort.flushOutput()
        serialPort.write(writeBytes)
        sleep(waitSeconds)
        readBytes = serialPortReadBytes(serialPort, maxBytesLength)
        print('     bytes written = ', writeBytes)
        print('     bytes read    = ', readBytes)
        return readBytes
    
    def repeatWriteBytes(serialPort, writeBytes, waitSeconds, repeatCount):
        print('     Begin repeatWriteOneByte(), ...') 
        for i in range(repeatCount):
            serialPortWriteBytes(serialPort, writeBytes)             
            sleep(waitSeconds)
        print('     End repeatWriteOneByte().')
        return
    
    def testRepeatWriteBytes(serialPort, writeBytes, waitSeconds, repeatCount):
        print('     Begin testRepeatWriteOneByte(), ...') 
        repeatWriteBytes(serialPort, writeBytes, waitSeconds, repeatCount)
        print('     End testRepeatWriteOneByte().')
        return
    
    def serialPortLoopBack(serialPort, writeBytes):
        print('   Begin serialPortLoopBack(), ...')
        maxBytesLength = 64
        waitSeconds    = 0.0
        serialPortWriteWaitReadBytes(serialPort, writeBytes, maxBytesLength, waitSeconds) 
        print('   End serialPortLoopBack()\n')
        return
    
    def repeatSerialPortLoopback(serialPort, writeBytes, repeatTimes):
        print('     Begin repeat serialPortLoopBack()')
        print('       repeating', repeatTimes, 'times, <Ctrl> C to abort, ...')
        maxBytes = 64
        waitSeconds = 0.0
        
        serialPort.flushInput()
        serialPort.flushOutput()
        
        for count in range(repeatTimes):
            serialPort.write(writeBytes)
            # sleep(waitSeconds)
            readBytes = serialPort.read(maxBytes)
    
        print('      End repeat serialPortLoopBack()')
        return
    
    def testRepeatSerialPortLoopback(serialPort, writeBytes, repeatTimes):
        print('   Begin testRepeatSerialPortLoopback(), ...')
        
        #print('     Serial port =', (serialPort0.name + ' '))
        #print('     WriteBytes  =', writeBytes)
        #print('     RepeatTimes =', repeatTimes)
        #print('     Now repeating', repeatTimes, 'times, <Ctrl> C to abort, ...\n')
        
        repeatSerialPortLoopback(serialPort, writeBytes, repeatTimes)
        print('    End   testRepeatSerialPortLoopback(), ...\n')
        return
    
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    
    '''
    # srv_util_01_v142.py
    # LX-824HV Testing v0.3  tlfong01 2020sep13hkt1334
    
    # SendRequestVin = UU<0x01><0x03><0x1b><0xe0>             = /x55/x55/x01/x03/x1b/xe0
    # RecvReplyVin   = UU<0x01><0x05><0x1b><0x03><0x14><0xc7> = /x55/x55/x01/x05/x1b/x03/x14/xc7
    #                                                                               /xcc/x13
    #                                                         =                     /xb1/x13                                             
    #                                                         =                     /xac/x13
    # 0x13ac = 5036
    # 0x13cc = 5068
    # 0x13b1 = 5041
    # 0x1403 = 5123
    
    # bytes written =  b'UU\x01\x03\x1b\xe0'
    # bytes read    =  b'UU\x01\x03\x1b\xe0UU\x01\x05\x1b\xfc\x13\xcf'
    
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    
    def convertTwoHexBytesToDec(twoHexBytes):
        lowHexByte  = twoHexBytes[0:1]
        highHexByte = twoHexBytes[1:2]
        print('Low  hex byte =', lowHexByte)
        print('High hex byte =', highHexByte) 
        return
    
    def testConvertTwoHexBytesToDec0x13a1():
        convertTwoHexBytesToDec(b'\x11\x22')
        return
    
    def bytesObjectTest():
        bytesObject = b'\x11\x22\x33\x44\x55'
        #bytesObject = b'12345'
        print(bytesObject)    
        bytes = bytesObject[2:3]
        print(bytes)
        intNum = int(bytes)
        print(intNum)    
    
        bytesObject = b'abc123'
        bytes = bytesObject[2:3]
        print(bytesObject)
        print(bytes)
    
        #byte1 = bytesObject[0:1]
        #byte2 = bytesObject[1:2]
        #print(byte1, byte2)
        #bytesList = [bytesObject[i:i+2] for i in range(0, len(bytesObject))]
        return
    
    def convertBytesObjectToBytesArray(bytesObject):
        bytesList   = [bytesObject[i:i+1] for i in range(0, len(bytesObject))]
        return bytesList
    
    def test01():
        print('      Begin test01(), ...')
        bytesObject = b'UU\x01\x03\x1b\xe0UU\x01\x05\x1b\xfc\x13\xcf'
        bytesList = convertBytesObjectToBytesArray(bytesObject)
        print('        bytes object =', bytesObject)
        byteListRequestPart       = [bytesObject[i] for i in (0, 1, 2, 3, 4, 5)]
        byteListReplyPart         = [bytesObject[i] for i in (6, 7, 8, 9, 10, 11, 12, 13)]
        byteListRequestPartInHex  = [hex(bytesObject[i]) for i in (0, 1, 2, 3, 4, 5)]
        byteListReplyPartInHex    = [hex(bytesObject[i]) for i in (6, 7, 8, 9, 10, 11, 12, 13)]
        print('        byte list request part        =', byteListRequestPart)
        print('        byte list reply   part        =', byteListReplyPart)
        print('        byte list request part in hex =', byteListRequestPartInHex)
        print('        byte list reply   part in hex =', byteListReplyPartInHex)
        print('      End   test01().')   
        return
    
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    '''
    
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
    
    # ### Old tests 2020sep15hkt2219
    # Set serial serialPort0 115200bd
    #setSerialPortBaudRate(serialPort0, 115200)
    
    # Loopback bytes object b'xyz123\r\n'
    #serialPortLoopBack(serialPort0, b'xyz123\r\n')
    
    # Loopback reuest Vin command b'\x55\x55\x01\x03\x1b\xe0'
    #serialPortLoopBack(serialPort0, b'\x55\x55\x01\x03\x1b\xe0')
    
    # Testing Rpi send/receive LeWanSoul request/reply bytes to/from LX-824HV
    # requestVin = b'\x55\x55\x01\x03\x1b\xe0'
    # repeatTimes = 10000000
    # testRepeatSerialPortLoopback(serialPort0, requestVin, repeatTimes)
    
    '''
    
    ### Sample output tlfong01  2020sep15hkt2132 ###
    
       Begin serialPortLoopBack(), ...
         bytes written =  b'UU\x01\x03\x1b\xe0'
         bytes read    =  b'UU\x01\x03\x1b\xe0UU\x01\x05\x1bS\x14w'
       End serialPortLoopBack()
    
       Begin testRepeatSerialPortLoopback(), ...
         Serial port = /dev/serial0 
         WriteBytes  = b'UU\x01\x03\x1b\xe0'
         RepeatTimes = 10000000
         Now repeating 10000000 times, <Ctrl> C to abort, ...
    
         Begin repeat serialPortLoopBack()
           repeating 10000000 times, <Ctrl> C to abort, ...
    
    ''' 
    
    # ********** ********** ********** ********** ********** ********** ********** 
    # ********** ********** ********** ********** ********** ********** **********
        
    # ### Main ### 
    
    # ### Old Tests 2020sep15hkt2222 ###
    # setSerialPortBaudRate(serialPort0, 115200)
    # serialPortLoopBack(serialPort0, b'xyz123\r\n')
    # serialPortLoopBack(serialPort0, b'\x55\x55\x01\x03\x1b\xe0')
    # requestVin = b'\x55\x55\x01\x03\x1b\xe0'
    # repeatTimes = 10000000
    # testRepeatSerialPortLoopback(serialPort0, requestVin, repeatTimes)
    # Testing Rpi send/receive LeWanSoul request/reply bytes to/from LX-824HV
    # ### New Tests ###
    
    def repeatRequestLx824HvVin():
        requestVin = b'\x55\x55\x01\x03\x1b\xe0'
        repeatTimes = 10000000
        testRepeatSerialPortLoopback(serialPort0, requestVin, repeatTimes)
        return
    
    setSerialPortBaudRate(serialPort0, 115200)
    serialPortLoopBack(serialPort0, b'xyz123\r\n')
    serialPortLoopBack(serialPort0, b'\x55\x55\x01\x03\x1b\xe0')
    repeatRequestLx824HvVin()
    
    # End of program
    
    # ### Sample OUtput  tlfong01  2020seo20hkt1432 ###
    
    '''
    >>> %Run srv_util_01_v163.py
       Begin setSerialPortBaudRate(), ...
         Serial port = /dev/serial0, Buad rate = 115200
       End   setSerialPortBaudRate(), ...
    
       Begin serialPortLoopBack(), ...
         bytes written =  b'xyz123\r\n'
         bytes read    =  b'xyz123\r\n'
       End serialPortLoopBack()
    
       Begin serialPortLoopBack(), ...
         bytes written =  b'UU\x01\x03\x1b\xe0'
         bytes read    =  b'UU\x01\x03\x1b\xe0UU\x01\x05\x1bJ\x14\x80'
       End serialPortLoopBack()
    
       Begin testRepeatSerialPortLoopback(), ...
         Begin repeat serialPortLoopBack()
           repeating 10000000 times, <Ctrl> C to abort, ...
           
           Traceback (most recent call last):
      File "/home/pi/Programs/programs/srv_util_01_v163.py", line 245, in <module>
        repeatRequestLx824HvVin()
      File "/home/pi/Programs/programs/srv_util_01_v163.py", line 239, in repeatRequestLx824HvVin
        testRepeatSerialPortLoopback(serialPort0, requestVin, repeatTimes)
      File "/home/pi/Programs/programs/srv_util_01_v163.py", line 97, in testRepeatSerialPortLoopback
        repeatSerialPortLoopback(serialPort, writeBytes, repeatTimes)
      File "/home/pi/Programs/programs/srv_util_01_v163.py", line 84, in repeatSerialPortLoopback
        readBytes = serialPort.read(maxBytes)
      File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 483, in read
        ready, _, _ = select.select([self.fd, self.pipe_abort_read_r], [], [], timeout.time_left())
    KeyboardInterrupt: Execution interrupted
    >>> 
    
    # ### End of sample output ###
    
    '''