44: Read line from USB

I'm not fond of C++ so try to pretend it's just C. So the supplied readline() doesn't fit. Doing a readline that worked for me took a few tries. So, I'll share it. (I'm sure it could be better)

#define spr(x) Serial.print(x)
#define spl(x) Serial.println(x)

char Buffer[80];

int readline(char *buffer, int len)
{
  int pos = 0;
  int tries = 0;
  char ch;

  while(tries < 200) { // arb. time out
    if(pos >= len) return -1;
    ch = Serial.read();
    if(ch > 0) {
      switch (ch) {
      case '\n': // Ignore new-lines
        break;
      case '\r': // Return on CR
        return pos;
      default:
        if (pos < len-1) {
          Buffer[pos++] = ch;
          Buffer[pos] = 0;
        }
      }
    } else { // no input ready
      delay(50);
    }
    ++tries;
  }
  // No end of line has been found, so return -1.
  return -1;
}

void setup() {
  Serial.begin(9600);
  delay(3000);
  Serial.println("Read line");

}

void loop() {
  int ct;
  if (readline(Buffer, 80) > 0) {
    spr("L:");spl(Buffer);
  } else {
    spl("timed out");
  }
}