Morse Code interpreter

[Sulaiman Habsi] and two classmates put together a Morse Code interpreter as a class project at Sultan Qaboos University. The system listens to a morse code signal using a microphone, then translates that input to text which is displayed on this character LCD.

The breadboarded circuit feeds an audio signal from the microphone, through an OpAmp, to the ADC of an ATmega8 microcontroller. The captured signal is stored as a byte in a special way. The three least-significant bits signify how many total dots or dashes are contained in the character, the remaining bits represent those dots and dashes with zeros and ones. A full description of this process is included in a PDF linked in the article above. As you can see in the video after the break, the hardware waits to process all of the signals once the full message has been received.

This would be a great add-on for a Morse Code practice keyer.

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Build your own 4-channel logic analyzer

If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis’] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

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