user85444: Currently I'm using:
  ADMUX = 0b01100000; //example
  for (int i = 7; i >= 0; i--) {
    Serial.print(bitRead(ADMUX, i));
  }

This correctly prints:
  01100000

But is there a simpler way?
Before coming up with above for loop I tried using just:
Serial.println(ADMUX);       //converts to integers: 96
Serial.println(ADMUX, BIN);  //leaves out leading zeros: 1100000
Serial.write(ADMUX);         //converts to ASCII char: `

Anything else I don't know of?

user85444: Another option:
#include <LibPrintf.h>
printf("%.8b", ADMUX); //prints: 0110000

The LibPrintf.h library is standard included on ESP boards.
%b stands for binary. .8 for 8 decimal places, which adds leading zero's to all truncated (binary) numbers.
It becomes *simpler if you wanted to print the variable name along with it like:
printf("ADMUX: %.8b", ADMUX); 

Results in:
ADMUX: 01100000

*Simpler in the way it now only occupies a single line of code.

85444: <p>Currently I'm using:</p>
<pre><code>  ADMUX = 0b01100000; //example
  for (int i = 7; i &gt;= 0; i--) {
    Serial.print(bitRead(ADMUX, i));
  }
</code></pre>
<p>This correctly prints:</p>
<pre><code>  01100000
</code></pre>
<p>But is there a simpler way?</p>
<p>Before coming up with above for loop I tried using just:</p>
<pre><code>Serial.println(ADMUX);       //converts to integers: 96
Serial.println(ADMUX, BIN);  //leaves out leading zeros: 1100000
Serial.write(ADMUX);         //converts to ASCII char: `
</code></pre>
<p>Anything else I don't know of?</p>
 85444: <p>Another option:</p>
<pre><code>#include &lt;LibPrintf.h&gt;
printf(&quot;%.8b&quot;, ADMUX); //prints: 0110000
</code></pre>
<p>The LibPrintf.h library is standard included on ESP boards.
%b stands for binary. .8 for 8 decimal places, which adds leading zero's to all truncated (binary) numbers.</p>
<p>It becomes *simpler if you wanted to print the variable name along with it like:</p>
<pre><code>printf(&quot;ADMUX: %.8b&quot;, ADMUX); 
</code></pre>
<p>Results in:</p>
<pre><code>ADMUX: 01100000
</code></pre>
<p>*Simpler in the way it now only occupies a single line of code.</p>
