The secret with a bar code decoder is i expect is to find the average length of the long and short marks and spaces and with a bar code you know the format is such that the first two and last two symbols are always short so you can allow for variations in the speed between different'swipes' and variations during each 'swipe' which I expect would be small.So yes it is exactly the same in principle,you could have a combined bar code and morse code decoder,very useful for the supermarket shelf stockers.'ere Bob this packet of crisps keeps sending SOS'