Simple morse code interpreter

Thread Starter

Refund

Joined Apr 5, 2012
2
Hey, I need to decide on a final project for my dld (breadboard) class and I was thinking about a morse code translator. One method would be to have one button which you press for a short time or a longer time to represent the dots and dashes. However, at the current time I'm not sure how to implement this type of system. Another idea is to have two buttons - one for a dot and one for a dash. The question is - how would I go about displaying this information as a letter?

Any ideas?
 

strantor

Joined Oct 3, 2010
6,798
Interpreting morse code via a pushbutton might present a bit more of a challenge than you would initially think. Reason being, everybody's rhythm is different. They say in morse code, an experienced person can even develop a "fist" - a distinctive way they signal, similar to the distinctive way each person writes. You are experienced in writing and can probably distinguish between different people's handwriting. Same with morse code. So your code needs to be flexible enough to recognize anybody's signals, without too rigorous of "rules" for the operator. For example, it might take one person 5 seconds to write a word in morse code, another might take 10 seconds. One person may know all the letters, and another person might really know 15 of them and hesitate or have to pause for though on the other 11. This isn't exactly what you need, but should give you some ideas.
 

Wendy

Joined Mar 24, 2008
23,429
When I was learning Morse way back when I made a quick and dirty Morse transmitter, to practice with.

I could see the problems with a receiver, but I've seen a lot of Hams do it at the conventions.
 

nerdegutta

Joined Dec 15, 2009
2,684
Side note:

I saw a competition once. Two girls with cellphones, and two rather old men with morse code devices. They got the same message to text to each other.

Guess who won.

I believe the easiest way would be 3 buttons. One for DOT one for DASH and one to tell the character/letter sequence is finished. But I guess that is cheating. :)
 

Bernard

Joined Aug 7, 2008
5,784
" 3 buttons" , not cheating, something like an automatic keyer where one position spits out dots, other position spits out dashes, operator spits out blanks, [ guess I'm an operator ].
 

MMcLaren

Joined Feb 14, 2010
861
The question is - how would I go about displaying this information as a letter?

Any ideas?
First of all, what are going to use? A microcontroller? Discrete logic? Then, what are you going to use for a display? An LCD?

If your design can distinguish between dits and dahs, it should be relatively easy to collect dits and dahs as 0's and 1's in a variable and then use that variable as an index into a table of ASCII characters. I did this with a little 12F683 Iambic Keyer project long ago.
 

Bernard

Joined Aug 7, 2008
5,784
If this project is mostly as a demonstration, then a simplified version might sufice. Only the letters that can be displayed on a 7 segment display & code letters of 5 bits or less = A, E, I, S; U is close but requires 7 bits. Input device is two buttons which give 1 or 0 & delayed clock, a few μ sec. which is inputted into a shift register, U9-U10. Example "A", 10111 folowed by 3 0's. When U2 sees 3-0's, clock is started which cycles counter U1, presenting the letter tri-state buffers one at a time to digital comparator U7-U8. When a match is found , clock is stopped, output could drive a LED next to the corisponding letter or fed to diode 7 seg display decoder.[ I see that A [a] is messed up?, should be a, b,c,e,f, & g. Also missing is the hard-wired code inputs to the buffers. This is just an outline, IC's are just possibilities.
 

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