title: input !== output signal - why?
body: <p>I'm using a STM32G431KB Nucleo board (nucleo_g431kb - 170MHz) with PlatformIO &amp; the Arduino framework.</p>
  <p>My simple code looks like this:</p>
  <pre class="lang-cpp prettyprint-override"><code>void setup()
  {
    pinMode(PA11, INPUT);
    pinMode(PA12, OUTPUT);
  }
  
  void loop()
  {
    if (digitalReadFast(PA_11) == HIGH) {
      digitalWriteFast(PA_12, HIGH);
    }
    else {
      digitalWriteFast(PA_12, LOW);
    }
  }
  </code></pre>
  <p>On pin 11 I got a well defined input signal like shown in the picture below (yellow signal). The blue signal in the picture is the one from the STM32 (pin 12).</p>
  <p>Now the blue signal is not that defined like the yellow one. In theory, they both should be identical, shouldn't they? How do I get the output signal mirroring the input signal? The chip should have enough power. I tried a pull-down resistor, but it didn't change anything. I guess, I'm simply stupi.</p>
  <p><a href="https://i.stack.imgur.com/n7h6G.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/n7h6G.jpg" alt="enter image description here" /></a></p>