Morse Code DecoderA 6.111 Final Project byChristopher StephensonWhy choose Morse Code?●Interesting to get a digital system to read●Relatively easy to get digital system to read●Good opportunities for interesting input / output●Gives something to play withMorse Code Specification●Timings based off dots which are 1 unit●Dash is 3 units●Pause between dots and dashes 1 unit●Pause between letters 3 units●Pause between words 7 unitsImage Copyright British LibrarySystem OverviewMorse CodeDecoderMorse CodeEncoderScreen Driver ScreenKeyboardMorse Code SourceAudio OutputScreen DriverText Buffer Screen DriverScreenCharacter PositionCharacter to draw at positionCharacter PositionOutput to ScreenNext Character from DecoderNext Character from EncoderNext Character from Encoder AvailableNext Character from Decoder AvailableCircular Buffer containing TextEncoderMorse CodeEncoderKeyboardAudio OutputScreenLookup Table Containing ASCII to Morse MappingsBeepsTextASCIICharactersDecoderSymboliser Converter MatcherSerial stream of timesSerial stream of dots, dashes and spacesStream of ASCII CharactersDemodulated and de-noised 1 bit Morse Code SignalDeals with turning beeps intonumbersProcesses the numbers to produce known tokensMatches the tokens toproduce ASCII CharactersConverter in Detail●Must determine the “Clock”●Must classify pulse lengths into dots and dashes●Must classify gaps as Inter character or inter word spaces●Uses Moving Average●Determines threshold lengths from previous stats●Allows it to be robust to change of symbol rateExtensions●Using an FFT, detect what part of an audio spectrum contains a Morse signal–Requires DSP to clean up and demodulate signal●Process “Non Ideal” Morse – i.e. Human tapped Morse–Requires that the Converter be made more robust●Recognize a tapper's Fist–Not sure if this is actually possible given the time, but might be worth a shot!TimelineWeek 1 Screen Driver CompleteWeek 2 Encoder CompleteWeek 3 Main Decoder CompleteWeek 4Frequency Scanner and Final Report Complete11/18 - 11/2411/25 - 12/0112/02 - 12/0812/09 - 12/12The aim is to get everything up to main decoder doneIf the project slips, the frequency scanner will be droppedIf the project under runs, a more robust converter will be addedSummary●Produce a Morse Code decoder●Decoder outputs to a screen●Can also produce Morse from Keyboard input●All done by the 12th of DecemberSamuel Morse,Inventor of the Morse
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