adding 2 binary numbers

johnny78 · Oct 13, 2022

hi Guys
one of the first lessons i've learned when started to learn programming was Numbers
but i forgot how to do this.

00010000
or
00000000
result
00010000

is it right i should use Or function ?
i've tried this with serial monitor to test what im doing but the result isnt what i need

Code:

int LedsDisplay = B00000000;
int PowerDisplay = B00010000;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println("Start");
  Serial.println(LedsDisplay);
  delay(1000);
  Serial.println(PowerDisplay);
  delay(1000);
  LedsDisplay =  ((LedsDisplay) || (PowerDisplay));
  Serial.println(LedsDisplay),BIN);
  delay(1000);
  int LedsDisplay = B00000000;
  int PowerDisplay = B00010000;
  delay(1000);
}

help me with this please

sorry for my english maybe i couldnt explain what i need exactly or do a useful search

thanks
Johnny

KlausST · Oct 13, 2022

Hi,

johnny78 said:
is it right i should use Or function ?

you already used OR function....

johnny78 said:
but the result isnt what i need

I don´t know "what you need".
So, as always, give clear informations:
* what do you expect it to do?
* what does it do instead?
(maybe with examples, drawings...)

****

OR and ADD are different functions.
use OR when you want to OR
but use ADD when you want to ADD.

example: binary:
001 OR 011 = 011
001 ADD 011 = 100
001 AND 011 = 001

Klaus

johnny78 · Oct 13, 2022

KlausST said:
Hi,

you already used OR function....

I don´t know "what you need".
So, as always, give clear informations:
* what do you expect it to do?
* what does it do instead?
(maybe with examples, drawings...)

****

OR and ADD are different functions.
use OR when you want to OR
but use ADD when you want to ADD.

example: binary:
001 OR 011 = 011
001 ADD 011 = 100
001 AND 011 = 001

Klaus

Hi

so OR is the right function i need but something wrong is going on
my code is giving another results

the result on serial monitor
_____________________
Start
0
16
1
Start
1
16
1
_____________________

i should get

Start
0
16
16

as example of what i need

a = 00001100
b = 00100000
_______________ Result
c =00101100

a = 00010000
b = 00100000
_______________ Result
c =00110000

thanks
Johnny

--- Updated Oct 13, 2022 ---

thanks Mr
i've found what i need exactly
my fault was using || instead of |

regards
Johnny

KlausST · Oct 13, 2022

Hi,

to your code:
What compiler and what IDE do you use?
If you get any compiler errors and warnings, please post them.

What worries me:
* "B00000000": it surely depends on compiler, but I know "&b00000000", "0b00000000" ... but no one with a "B" as first letter

johnny78 said:
LedsDisplay = ((LedsDisplay) || (PowerDisplay));

It looks like a "logical OR" instead of a bitwise OR.
so shouldn´t it be:
* (LedsDisplay | PowerDisplay);
* or (LedsDisplay OR PowerDisplay);

johnny78 said:
Serial.println(LedsDisplay),BIN);

This I expect to cause a compiler error.
It has one opening bracket, but two closing brackets.

****
BTW: I recommend to declare your variables explicitely how you want it to be.
instead of "int LedsDisplay ..."
better write "uint8_t LedsDisplay..." ( unsigned 8 bit )
--> so it´s clear that you force it to be an 8 bit variable without a SIGN bit.

"int" can depend on complier and processor and may be an 8 bit, 16 bit, 32 bit ... variable.

Also it´s a good idea to write in the first lines of code for which type of microcontroler the code is written. Some compiler need this, but you are free to write it as comment.
And especially if you post this code in public (forum) ...

Klaus

johnny78 · Oct 13, 2022

KlausST said:
Hi,

to your code:
What compiler and what IDE do you use?
If you get any compiler errors and warnings, please post them.

What worries me:
* "B00000000": it surely depends on compiler, but I know "&b00000000", "0b00000000" ... but no one with a "B" as first letter

It looks like a "logical OR" instead of a bitwise OR.
so shouldn´t it be:
* (LedsDisplay | PowerDisplay);
* or (LedsDisplay OR PowerDisplay);

This I expect to cause a compiler error.
It has one opening bracket, but two closing brackets.

****
BTW: I recommend to declare your variables explicitely how you want it to be.
instead of "int LedsDisplay ..."
better write "uint8_t LedsDisplay..." ( unsigned 8 bit )
--> so it´s clear that you force it to be an 8 bit variable without a SIGN bit.

"int" can depend on complier and processor and may be an 8 bit, 16 bit, 32 bit ... variable.

Also it´s a good idea to write in the first lines of code for which type of microcontroler the code is written. Some compiler need this, but you are free to write it as comment.
And especially if you post this code in public (forum) ...

Klaus

hi
im using Arduino IDE & no i didn't got errors
maybe the compiler corrected it for me

anyway thanks for the valuable informations you've provided was not in mind at all

best regards
Johnny

FvM · Oct 13, 2022

johnny78 said:
im using Arduino IDE & no i didn't got errors
maybe the compiler corrected it for me

Interpreting a logic or as bitwise or is not correction, it's a fault.
The stanadard is pretty clear about this
The || operator shall yield 1 if either of its operands compare unequal to 0; otherwise, it yields 0. The result has type int

johnny78 · Oct 13, 2022

FvM said:
Interpreting a logic or as bitwise or is not correction, it's a fault.
The stanadard is pretty clear about this
The || operator shall yield 1 if either of its operands compare unequal to 0; otherwise, it yields 0. The result has type int

hi
i was talking about this error which Klaus mentioned about it
--------------------------------

johnny78 said:
Serial.println(LedsDisplay),BIN);

This I expect to cause a compiler error.
It has one opening bracket, but two closing brackets.
-----------------------------------------------------------
& i've used || operator by mistake instead of |

best regards
Johnny

adding 2 binary numbers

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