void setup() {
  char byteRead[1];

  Serial.begin(115200);
  Serial.setTimeout(100);

  int numBytes = 0;

  Serial.println("Please enter a character (100ms timeout)");

  while (!Serial.available());
  numBytes = Serial.readBytes(byteRead, 1);

  Serial.print("|"); Serial.print(byteRead[0]); Serial.print("| Number of bytes read: "); Serial.print(numBytes);
}

void loop() {
}