Hi I'm new to Arduino and was wondering how i defined one character as another
Lets say I had an "e" and wanted a program to change that to an "I". How would i do that?
Or consider
using a conditional filter something like
// if (rc = 'e') { // Aieee! this mistakenly assigns `e` to `rc ` inststead if the intended equality test
if (rc == 'e') { // This is the intended equality test (Thanks @alto777)
{ rc = 'I';
}
You could use a pointer, perhaps.
constexpr char e = 'e';
constexpr char I = 'I';
const char *ptr = e;
if (condition)
*ptr = I;
Fixed that for ya'.
a7
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Needs work.
At the very least, you need to take the address...
# include <stdio.h>
char e = 'e';
char I = 'I';
int main()
{
printf("Hello World\n");
char *ptr = &e;
if (true)
*ptr = I;
printf("%d (%c)", e, e);
return 0;
}
I had to keep losing const stuff I don't use and don't understand. To get it to compile and give the desired reslut:
Hello World
73 (I)
...Program finished with exit code 0
Press ENTER to exit console.
a7
Hello nerdytaco
You have to design your own code book for the transformation.
constexpr char codeBook[] {'e','z' ....... and so on
Do you will design your own Enigma ?
One method:
char char_out;
void encode(char char_in) {
switch(char_in) {
case 'a':
char_out = 'b';
break;
case 'b':
char_out = 'c';
break;
// . . . and so on
default:
// use a default value, raise an error message, whatever else you'd like
break;
}
}
Another way:
char('a' + 1) // = b
1 Like
char('a'+ (char_in - 'a' +1)%26))
as in
void setup() {
Serial.begin(115200);
for (char char_in = 'a'; char_in <= 'z' ; char_in++) {
Serial.print(char_in);
Serial.println(char('a' + (char_in - 'a' + 1) % 26));
}
}
void loop() {
}
Is the compiler smart enough to use optimize that modulo operation into an if?
I like the completeness of your answer.
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It doesn't look like it's smart enough:
// Excerpt from Wokwi F1/View Compiled Assembly Code Listing:
...
Serial.begin(115200);
for (char char_in = 'a'; char_in <= 'z' ; char_in++) {
Serial.print(char_in);
Serial.println(char('a' + (char_in - 'a' + 1) % 26));
510: 0a e1 ldi r16, 0x1A ; 26
512: 10 e0 ldi r17, 0x00 ; 0
return write(str);
}
size_t Print::print(char c)
{
return write(c);
514: 6c 2f mov r22, r28
516: 60 5a subi r22, 0xA0 ; 160
518: 86 e1 ldi r24, 0x16 ; 22
51a: 91 e0 ldi r25, 0x01 ; 1
51c: 0e 94 ff 00 call 0x1fe ; 0x1fe <_ZN14HardwareSerial5writeEh>
520: ce 01 movw r24, r28
522: b8 01 movw r22, r16
524: 0e 94 de 02 call 0x5bc ; 0x5bc <__divmodhi4>
528: 61 e6 ldi r22, 0x61 ; 97
52a: 68 0f add r22, r24
52c: 86 e1 ldi r24, 0x16 ; 22
52e: 91 e0 ldi r25, 0x01 ; 1
530: 0e 94 ff 00 call 0x1fe ; 0x1fe <_ZN14HardwareSerial5writeEh>
void clearWriteError() { setWriteError(0); }
...
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When possible I avoid the use of division and modulo operations on most of these, unless mission critical, but you are certainly correct in bounding your operation.
char_in += 1;
if (char_in > 'z') char_in -= 26;
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Well me and my friend are trying to make a morse code translator with one arduino sending morse code and the other receiving it in "." and "-" and that needs to be translated to letters
Standard Morse supports punctuation natively. "." is ".-.-.-"
Add them to your look up table.
Next time you post a question, please reveal up front what you're up to.
I wrote Magic Morse many years ago, take anything you can use:
Magic Morse on Arduino | Trybotics
Some background:
Notes behind Magic Morse | PICAXE Forum
Magic Morse is an algorithm, thus once the Magic number is calculated (or known) one can easily derive Morse or Character.
Code:
(c) Copyright 2011 M. Ray Burnette
ALL COMMERCIAL RIGHTS RESERVED
Example: 0 1 0 = R
There are 3 elements, therefore bits 1, 2, 4 = 3 (1 / 1 / 0)
The 1 is in the second character, therefore it is
weighted with a bit value of 16 ( 0 / 1/ 0 / 0 / 0 )
The Index value is 1 + 2 + 16 = 19
Example: 1 1 = M
There are 2 elements, therefore bits 1, 2, 4 = 2 (0 / 1 / 0)
The 1 is the first and second character, therefore
weighting is 8 and 16 = 24 (1 / 1 / x / x / x)
The Index value is 2 + 24 = 26
Alphabet
ASCII INDEX MORSE CODE # Elements- ---------- weight ---------
1 2 4 8 16 32 64 128
E 69 1 DIT 1 0 0 0 x x x x
I 73 2 DIT DIT 0 1 0 0 0 x x x
S 83 3 DIT DIT DIT 1 1 0 0 0 0 x x
H 72 4 DIT DIT DIT DIT 0 0 1 0 0 0 0 x
5 53 5 DIT DIT DIT DIT DIT 1 0 1 0 0 0 0 0
T 84 9 DAH 1 0 0 1 x x x x
N 78 10 DAH DIT 0 1 0 1 0 x x x
D 68 11 DAH DIT DIT 1 1 0 1 0 0 x x
B 66 12 DAH DIT DIT DIT 0 0 1 1 0 0 0 x
6 54 13 DAH DIT DIT DIT DIT 1 0 1 1 0 0 0 0
A 65 18 DIT DAH 0 1 0 0 1 x x x
R 82 19 DIT DAH DIT 1 1 0 0 1 0 x x
L 76 20 DIT DAH DIT DIT 0 0 1 0 1 0 0 x
M 77 26 DAH DAH 0 1 0 1 1 x x x
G 71 27 DAH DAH DIT 1 1 0 1 1 0 x x
Z 90 28 DAH DAH DIT DIT 0 0 1 1 1 0 0 x
7 55 29 DAH DAH DIT DIT DIT 1 0 1 1 1 0 0 0
U 85 35 DIT DIT DAH 1 1 0 0 0 1 x x
F 70 36 DIT DIT DAH DIT 0 0 1 0 0 1 0 x
IN 0 41 DAH DIT DAH 1 1 0 1 0 1 x x <--- Prosign for Invite
K 75 43 DAH DIT DAH 1 1 0 1 0 1 x x
C 67 44 DAH DIT DAH DIT 0 0 1 1 0 1 0 x
__________________________________________________________________________________
Full list of standard ASCII --> Magic Morse
Alpha
ASCII
Magic
0 48 253
1 49 245
2 50 229
3 51 197
4 52 133
5 53 5
6 54 13
7 55 29
8 56 61
9 57 125
A 65 18
B 66 12
C 67 44
D 68 11
E 69 1
F 70 36
G 71 27
H 72 4
I 73 2
J 74 116
K 75 43
L 76 20
M 77 26
N 78 10
O 79 59
P 80 52
Q 81 92
R 82 19
S 83 3
T 84 9
U 85 35
V 86 68
W 87 51
X 88 76
Y 89 108
Z 90 28
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Yea... Arduino was a bit different in 10+ years back 
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