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  • Morse Code Decoder

  • Created: May 19, 2014

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Morse code is used in telecommunication; it is a method of transmitting and receiving coded information. Each character (letter or numeral) is coded/represented by a unique sequence of dots and dashes. Compared to voice, Morse code is less sensitive to poor signal conditions, yet still comprehensible to humans without a decoding device, therefore, a useful alternative to synthesized speech for sending automated data to skilled listeners (radio operator) on a voice channel.

The project's first part is composed of an electret microphone followed by a common emitter follower amplifier; this transistor amplifier also acts as a first level bandpass filter. Its band edges are determined by the size of the coupling capacitors, and the feedback capacitor between the transistor's base and collector terminals. The next part of the project is the PLL (phase lock loop) tone detector/decoder NE567; its output is a one-zero pattern replicating the dots-and-dashes sequence of the received signal. This output drives both an input to the PIC16F84 microcontroller and an LED that is used as a receiver tuning aid.

Another part is the PIC16F84 microcontroller, its function is to measure the duration of the one-zero input string from the tone decoder, and translate the pattern into DOTs, DASHs, symbol spaces, character spaces, or word spaces. Each of the symbols that are received, an equivalent "code word" is assembled and is convert to its ASCII equivalent character for display. And for the final part, the CPU interfaces to the LCD line display, sending ASCII characters to it and monitoring LCD status.



I published a quite similar Morse decoder design in the October 1976 issue of BYTE magazine using a 567 and a Motorola 6800 processor. I'm very curious to see the micro controller code for this project!

Posted: Mar 26, 2015


I remember that article. It's viewable on-line at http://tinyurl.com/6800morser

Posted: Mar 27, 2015


Where's the code??

Posted: Sep 03, 2015


Which software can i use for making circuit diagram. Please help me

Posted: Dec 19, 2015

Paulo Borensztein

A PIC project without a code? And the transistor?

Posted: Jan 05, 2016


Kttawhid, you can use this site (schematics.com) for making circuit diagram :)

Posted: Apr 06, 2016


you can visit this site for the code and reference. http://www.hamradio.cc/projects/Morse_Code_Decoder_Circuit.php#morse_decoder

Posted: Apr 06, 2016

Nice Information.

Posted: Dec 27, 2016


Nice schematic

Posted: May 09, 2019


Can anybody reach or use the Editor?! It just says: "The app is loading, please wait. loading component data..." Am I the only one who can not reach any of the projects for a month now?

Posted: Mar 10, 2020



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