When I'm running some test on my encoder motors using the following provided code by Makeblock, it appears that the `if..else..` statement is not mutually exclusive ie. I can control Encoder\_1 and Encoder\_2 at the same time. How come?

```cpp
case ENCODER_BOARD:
      if(port == 0)
      {
        uint8_t slot = readBuffer(7);
        int16_t speed_value = readShort(8);
        speed_value = -speed_value;`

        if(slot == SLOT_1)
        {
          Encoder_1.setTarPWM(speed_value);
        }
        else if(slot == SLOT_2)
        {
          Encoder_2.setTarPWM(speed_value);
        }
        else if(slot == SLOT_3)
        {
          Encoder_3.setTarPWM(speed_value);
        }
        else if(slot == SLOT_4)
        {
          Encoder_4.setTarPWM(speed_value);
        }
      }

int16_t readShort(int16_t idx)
{
  valShort.byteVal[0] = readBuffer(idx);
  valShort.byteVal[1] = readBuffer(idx+1);
  return valShort.shortVal; 
}

uint8_t readBuffer(int16_t index)
{
  if(BluetoothSource == DATA_SERIAL)
  {
    return buffer[index];
  }
  else if(BluetoothSource == DATA_SERIAL2)
  {
    return bufferBt1[index];
  }
  else if(BluetoothSource == DATA_SERIAL3)
  {
    return bufferBt2[index];
  }
}

```

All the code are taken from [here](https://github.com/Jc7tee/OPEN__MegaPi/blob/master/Firmware_for_MegaPi.ino) and I am not the owner. I myself still studying how these whole code works. I am hoping someone out there who have experience with these kind of implementations be able to help me out.