void setup() {
  Serial.begin(115200);
  float x, y;
  int height = 6;  
  int width = 6;   

  y = height;
  while (y >= -height) {  
    x = -width;
    while (x <= width) {  
      
      if (abs(y) + abs(x) <= height) {
        Serial.print("*");
      } else {
        Serial.print(" ");
      }
      
      x += 1;
    }
    Serial.println();
    y -= 1;
  }
}

void loop() {
}