Convert Long to binary - least signifant bit first I have found an Arduino function which converts a 2-bytes-long-value to a binary value.

e.g. I call sendCommand(0x05) And it gives me an output:

00000101

void sendCommand(unsigned long command){
  for (unsigned long  mask = 1UL &lt;&lt; (7);  mask;  mask &gt;&gt;= 1) {

    if (command &amp; mask) {

    Serial.print( "1" );
    } else {

    Serial.print( "0" );
    }
  }
}


my Problem is, that I want to have the Least significant bit first. How do I have to adjust this function to achieve this?

e.g.
sendCommand(0x05)
shall give an output:

10100000
void sendCommand(unsigned long command){
  for (unsigned long  mask = 1UL; mask&lt;256UL;  mask &lt;&lt;= 1) {

    if (command &amp; mask) {

    Serial.print( "1" );
    } else {

    Serial.print( "0" );
    }
  }
}


PS a long is actually 4 bytes long. But your code only uses 1 byte of it.