Reference →

isControl()

Analyse if a char is a control character. Returns true if thisChar is a control character. isControl(thisChar)
thisChar: variable. Allowed data types: char. true: if thisChar is a control character.

		
if (isControl(myChar)) {  // tests if myChar is a control character
  Serial.println("The character is a control character");
}
else {
  Serial.println("The character is not a control character");
}