How to print transposed matrix of binary numbers without losing leading zeros?

Projects Programming
1

I have an array

int before[] = {B0100, B1000, B0001, B0010};

I don't want it to be printed like this:

B0100
B1000
B0001
B0010

but like this

0 1 0 0
1 0 0 0
0 0 0 1
0 0 1 0

I am out of ideas. Thanks in advance.

2

looks like school work

show us at least what you tried.. It's not difficult using a couple for loop and bitRead()

here is an idea to explore

int before[] = {B0100, B1000, B0001, B0010};

void printBinary(int a[], size_t arraySize, byte nbBits) {
  for (size_t i = 0; i < arraySize; i++) {
    for (int b = nbBits - 1; b >= 0; --b) {
      // print something smart here using  bitRead()
      // print something smart if b is not null
    }
    Serial.println();
  }
}

void setup() {
  Serial.begin(115200);
  printBinary(before, sizeof before / sizeof * before, 4);
}

void loop() {}
3 
int before[] = {B0100, B1000, B0001, B0010};

void setup()
{
  Serial.begin(115200);
  for (int row = 0; row < 4; row++)
  {
    for (int bit = 3 ; bit >= 0 ; bit--)
    {
      Serial.print(bitRead(before[row], bit));
      Serial.print(" ");
    }
    Serial.println();
  }
}

void loop()
{
}

Why are you wasting memory ny storing 4 bit values in a 16 bit in array ?

4

Because I want them to be printed on OLED display

5

Why do they have to be ints when you could at least make them bytes ? That would waste less memory but could still be improved on if needs be

1 Like
6

I tried modified version of your code:

void printByteDisplay(byte aByte, byte nbBits = 8, int a=0, int b=0) { 
  if (nbBits == 0) return;
  for (int i = 0 ; i <= nbBits - 1; i++) {
    //display.write(bitRead(aByte, i) == 0 ? '0' : '1'); // 
    display.setCursor(a, b+i*9);
    display.println(bitRead(aByte, i) == 0 ? '0' : '1');
    //Serial.println(bitRead(aByte, i) == 0 ? '0' : '1');
  }
  //Serial.println("");
}

Achtung: I am trying to print it on OLED display. The problem is that it shows
1
0
0
0

instead of

0
0
0
1

7

Thank you, I will change the type.

8

I changed

display.println(bitRead(aByte, i) == 0 ? '0' : '1');

to

display.println(bitRead(aByte, nbBits - 1-i) == 0 ? '0' : '1');

Now it works perfect. Thank you for your answer.

9

great :slight_smile:

(you don't want println() but just print and could use write() instead of print() when you send only 1 char, it's more efficient)

10

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