It is posible to use the a similar B00000000 byte format for int data types ?

Projects Programming
1

Hello, i am working with a couple of 10x10 matrix, one matrix recieves the 10 digit BINARY number and the other one displays the input. My previous prototype was working on a 8x8 matrix so the byte data type fits perfect to me for the input, indeed my data input variables were declared as follows:

byte inputState [size] = {  B00000000, B00000000, B00000000, B00000000, B00000000, B00000000, B00000000, B00000000 };

I was able to read data using bitRead:

void readBitState(){

bool currentState [] = { 0,0,0,0,0,0,0,0 };

    for(int i = 0; i < sizeof(inputState); i++){

      Serial.print((String)"State at " + i + " : ");
      
        for(int j = 0; j < sizeof(inputState); j++){

            currentState[i] = bitRead(inputState[i],j);
            Serial.print((String)state[i]);
        }
      
      Serial.println(" ");

    }
    
}

Now i need to use not 8 but 10 digits per row, since my input is Binary i understand that each of my new input (row) requires 2 bytes, Since i prefer not to use the long data type that uses 4 bytes of memory i need to know how it is possible to use the B00000000 byte format similarly but for the INT data type?

Thanks in advance.

2

Yes. You can initialize any variable using any of several human readable text representations for numbers, including the 0Bxxx format.

3

Thanks, i read the documentation and now understand the mistake was passing the data formated as:

B0000000000

instead of:

0B0000000000

So in summary i was ignoring the 0 before the B, now i am able to compile and run my code well. Thank you !

4

The "Bxxx" format is a bunch of names defined by the Arduino core library. It only goes up to 8 bits and makes it hell for anyone wanting to use the names B0, B1, B00, B01, B10, B11...

The 0Bxxxx (or 0bxxxx) is a compiler thing and works for any reasonable length. At least 64 bits (I just checked):

uint64_t binary = 0b0000000000000000000000000000000000000000000000000000000000000000;
5

Thanks for the information sir, Dealing with bytes at this level is not common where i come from, however, now i know how to use the 0bxxx format but at the same take into consideration the boundaries.

6

Dealing with bytes and 0b or B prefixes isn't common anywhere - most of us use hex.

7

TheMemberFormerlyKnownAsAWOL:
Dealing with bytes and 0b or B prefixes isn't common anywhere - most of us use hex.

Historical note for young programmers:
Back before a 'byte' became standardized at 8 bits and hexadecimal became standard for representing blocks of bits, many programmers used octal. Even to this day, the C and C++ programming languages treat an integer constant as octal if it starts with a zero.

If you try to 'neaten' your columns by left padding with zeroes you will have problems.

int values[] = {
    0000, 0025, 0050, 0075,  // In decimal these are:   0,  21,  40,  61
    0100, 0125, 0150, 0175,  // In decimal these are:  64,  85, 104, 125
    0200, 0225, 0250, 0275,  // In decimal these are: 128, 149, 168, 189
    0300, 0325, 0350         // In decimal these are: 192, 213, 232
};

These are interpreted as octal. IF you are lucky you will use the digits 8 or 9 and get an "invalid digit in octal constant" error.