Pasted

<?php
//
// after http://wormfood.net/avrbaudcalc
// reprogrammed by Uwe Zimmermann, 2019-11-17
//
  function bg_color($err = 0)
  {
    if (abs($err) < 0.1)
    {
      $bg = "#51ff00";
    }
    else
    {
      if (abs($err)<=1)
      {
        $bg = "#42cc02";
      }
      else
      {
        if (abs($err)<=2)
        {
          $bg = "#00990a";
        }
        else
        {
          if (abs($err)<=3)
          {
            $bg = "#fff71c";
          }
          else
          {
            if (abs($err)<=4)
            {
              $bg = "#ff9d1c";
            }
            else
            {
              $bg = "#ff1c1c";
            }
          } 
        }
      }
    }
    return $bg;
  }
 
function wormfood_table($F_CPU=16000000)
{
$i = 0;
$baud=array(300,600,1200,2400,4800,9600,14400,19200,28800,57600,76800,115200,128000,230400,256000);  
 
echo "<table border=\"1px\">";
$FCPU = number_format ( $F_CPU , 0 , '.' , '&thinsp;' );
printf("<tr><th colspan=\"7\" style=\"text-align:center\"><i>f<sub>osc</sub></i> = %s Hz</th></tr>",$FCPU);
echo "<tr><th colspan=\"1\" rowspan=\"2\">nominal Bit rate</th><th colspan=\"3\">U2Xn=0</th><th colspan=\"3\">U2Xn=1</th></tr>";
echo "<tr><th>UBRR</th><th>actual Bit rate</th><th>error</th><th>UBRR</th><th>actual Bit rate</th><th>error</th></tr>";  
 
for ($i=0;$i<count($baud);$i++) 
{
  $UBRR   = round(($F_CPU / (16 * $baud[$i])) -1);  
  $UBRR2x = round(($F_CPU  / (8 * $baud[$i])) -1); 
  if ($UBRR < 0)
  {
      $UBRR = 0;
  }
  if ($UBRR2x < 0)
  {
      $UBRR2x = 0;
  }
  $realbaud = round(($F_CPU/16)/($UBRR+1));
  $err = 100*($realbaud-$baud[$i])/$baud[$i];
  $realbaud2x = round(($F_CPU/8)/($UBRR2x+1));
  $err2x = 100*($realbaud2x-$baud[$i])/$baud[$i];
  echo "<tr><td style=\"text-align=right;\">$baud[$i]</td>";
 
  if ($UBRR > 4095)
  {
    $bg = "#c7c7c7";
  }
  else
  {
    $bg = bg_color($err);
  }
 
  printf("<td style=\"background-color:%s;text-align=right;\">%d</td><td style=\"background-color:%s;text-align=right;\">%d</td><td style=\"background-color:%s;text-align=right;\">%.1f%%</td>",$bg,$UBRR,$bg,$realbaud,$bg,$err);
  if (($UBRR2x > 4095) or ($UBRR2x < 0)) 
  {
    $bg = "#c7c7c7";
  }
  else
  {
    $bg = bg_color($err2x);
  }
  printf("<td style=\"background-color:%s;text-align=right;\">%d</td><td style=\"background-color:%s;text-align=right;\">%d</td><td style=\"background-color:%s;text-align=right;\">%.1f%%</td>",$bg,$UBRR2x,$bg,$realbaud2x,$bg,$err2x);
  echo "</tr>";
 }
 echo "</table>";
}
?>