     digitalWrite(10, states[state]);
     digitalWrite(9, states[state + 1 & 0x3]);
     state = (state + dir) & 0x3;
+    count--;
+    if (count == 0) 
+      enable = false;
   }
 }
 

    else
      Serial.print("Disabled ");

    Serial.print(rate * 2);
    Serial.println("uS");

  }

        if (rate < 100) rate = 100;
        Timer1.setPeriod(rate);
        break;
      case 'p':
        enable = 1;
        count = 20;
        break;
    }


