Scanning bit state in a binary number

Using Arduino Programming Questions
#1

Hi,

I just wrote a program to practice bit masking and bitwise operands. The reason I want to do this is I currently have a library with multiple outputs that are in an on off state. Right now the state is represented as an integer but I suppose I could store up to 8 output states in a single byte with a little more sophistication. I can also save memory. Here is my program:

byte value = B00100100;
byte currentbit;

void setup() {
  Serial.begin(9600);

}

void loop() {
  delay(500);
  Serial.println(value, BIN);
  delay(500);
  Serial.println();
  for(byte mask=00000001; mask>0; mask<<=1){ 
    currentbit= value & mask;   
    Serial.println(currentbit, BIN);
    delay(200);
  }
  Serial.println();  
}

When run the output is the following:

100100

0
0
100
0
0
100000
0
0

What must I do to my code such that the bit state of that single location is printed and doesn’t take into account the number of bits before it. I would like my code to print in the following manner:

100100

0
0
1
0
0
1
0
0

Thank you for taking a look at this.

#2

Try:

byte value = B00100100;
byte currentbit;

void setup() {
  Serial.begin(9600);

}

void loop() {
  delay(500);
  Serial.println(value, BIN);
  delay(500);
  Serial.println();
  for(int mask = 1; mask < 256; mask <<= 1){ 
    currentbit = value & mask;   
    if(currentbit)
    {
      currentbit = 1;
    }

    Serial.println(currentbit, BIN);
    delay(200);
  }
  Serial.println(); 
  while(1); // stop here
}
#3

You can also cast to bool

currentbit= (bool) (value & mask);

Or use bitRead if you want a simpler method

for ( uint8_t i = 0; i < 8; i++ )
  currentbit = bitRead( value, i );

Also you may be interested by a struct of bit fields.

#4

@guix

currentbit= (bool) (value & mask) ;

Nice.

#5