Thread: Morse Code(Going the other way)

I have wrote the programming code that converts english to morse, but how do i go back the other way. This function does not read or write to files.

Code:

void morse_code_letters(char morse_strings[91][6])
{
	//morse code letters using string copy
	strcpy (morse_strings['A'], ".-");
	strcpy (morse_strings['B'], "-...");
	strcpy (morse_strings['C'], " -.-.");
	strcpy (morse_strings['D'], "-..  ");
	strcpy (morse_strings['E'], ".");
	strcpy (morse_strings['F'], "..-.");
	strcpy (morse_strings['G'], "--.");
	strcpy (morse_strings['H'], "....");
	strcpy (morse_strings['I'], "..");
	strcpy (morse_strings['J'], ".---");
	strcpy (morse_strings['K'], "-.-");
	strcpy (morse_strings['L'], ".-..");
	strcpy (morse_strings['M'], "--");
	strcpy (morse_strings['N'], "-.");
	strcpy (morse_strings['O'], "---");
	strcpy (morse_strings['P'], ".--.");
	strcpy (morse_strings['Q'], "--.-");
	strcpy (morse_strings['R'], ".-.");
	strcpy (morse_strings['S'], "...");
	strcpy (morse_strings['T'], "-");
	strcpy (morse_strings['U'], "..-");
	strcpy (morse_strings['V'], "...-");
	strcpy (morse_strings['W'], ".--");
	strcpy (morse_strings['X'], "-..-");
	strcpy (morse_strings['Y'], "-.--");
	strcpy (morse_strings['Z'], "--..");
	// morse code numbers using string copy
	strcpy (morse_strings['1'], ".----");
	strcpy (morse_strings['2'], "..---");
	strcpy (morse_strings['3'], "...--");
	strcpy (morse_strings['4'], "....-");
	strcpy (morse_strings['5'], ".....");
	strcpy (morse_strings['6'], "-....");
	strcpy (morse_strings['7'], "--...");
	strcpy (morse_strings['8'], "---..");
	strcpy (morse_strings['9'], "----.");
	strcpy (morse_strings['0'], "-----");
	// morse code characters using string copy
	strcpy (morse_strings['.'], ".-.-.-");
	strcpy (morse_strings[','], "--..--");
	strcpy (morse_strings['?'], "..--..");
	strcpy (morse_strings[' '], " ");
}

Code:

char* letter_to_morse(char *morseTester1, char morse_strings[91][6])
{
	int len = strlen(morseTester1);
	char *result = malloc(len * 6 + 1);
    int i;

	*result = NULL;
	for (i = 0; i < len; i++)
	{
		strcat(result, morse_strings[toupper( morseTester1[i++])]);
	}
	return result;
}

NOTE: char *morseTester1 = "Hello world"





I need to know how to convert from morse to english

Thanks!

I would think you would want to be more careful with your spacing than you are.

Otherwise, just go the other way -- figure out where your morse character starts and stops (hint: you may want to be more careful with your spacing than you are), compare that with your morse characters (hint: you use strcmp to compare strings) and there you go. Since there's only three dozen characters, a linear search would not be horrible, so you can just loop through your characters until you find one.

Thanks, So would i use a while loop to do that. And i am confused on like where to start and what variables to compare?

You have 91 elements in your array, so you can map ASCII codes to morse code strings, but you need to make sure you initialize all 91 elements to something, to avoid garbage strings. Then, use either a while or do loop to scan through morse_strings, and a strcmp to check the value in question against the value in morse_strings[i]. If they match, return i, which will map directly to a valid ASCII character that should be suitable for printing to screen.

Originally Posted by ssharish2005

I dont know why you need an array with 91 elements, when your not using all of the elements you declared. You could do the following to just reduce the whole lot down to a resonable size

Code:

char morse_strings[41][6];
.
.
strcpy (morse_strings['0'-'0'], ".-");
strcpy (morse_strings['1'-'0'], "-...");
strcpy (morse_strings['2'-'0'], " -.-.");
.
.
strcpy (morse_strings['Z'-'0'], " -.-.");

ssharish

Probably because his way produces direct morse to ascii and ascii to morse conversion based on the array index.

Originally Posted by ssharish2005

I dont know why you need an array with 91 elements, when your not using all of the elements you declared. You could do the following to just reduce the whole lot down to a resonable size

Code:

char morse_strings[41][6];
.
.
strcpy (morse_strings['0'-'0'], ".-");
strcpy (morse_strings['1'-'0'], "-...");
strcpy (morse_strings['2'-'0'], " -.-.");
.
.
strcpy (morse_strings['Z'-'0'], " -.-.");

ssharish

That would make it a bit difficult to use comma and period.

Code:

char* morse_to_letter(char *morseTester2, char morse_strings[91][6])
{
	int i = 0, count = 0;
	char morse[500 + 1];

	while (strcmp(morse, morse_strings[i]) == 0)
	{
		return i;
		count++;
	}

	return i;
}

do u have any suggestions? it returns NULL

and ya its because of the ASCII value

And where's the data you intend to check?

thats what its supposed to be i believe

Quzah brings up a good point. When one transmits morse code, there is often a slight pause between letters and a longer pause between words. In your code, perhaps you want to represent this by putting a single space between each letter, and perhaps 2 or 3 spaces between words.

Ummm... you need to know what your counting...

Code:

{
	int i = 0
	while (strcmp(morse, morse_strings[i++]) != 0 && i < 96);
	return i-1;
}

Using this in a function you need to somehow pre-divide the longer morse string into letters and feed the function individual letters... so that it can evaluate each morse string separately.