code: func (b *IOPinDriver) WritePinIOConfig(config int) (err error) {
  	b.ioMask = config
  	data := &bytes.Buffer{}
  	binary.Write(data, binary.LittleEndian, uint32(config))
  	err = b.adaptor().WriteCharacteristic(pinIOConfigCharacteristic, data.Bytes())
  	return
  }
docs: // WritePinIOConfig writes the pin I/O config mask for all pins