code: func (b *IOPinDriver) WritePinADConfig(config int) (err error) {
  	b.adMask = config
  	data := &bytes.Buffer{}
  	binary.Write(data, binary.LittleEndian, uint32(config))
  	err = b.adaptor().WriteCharacteristic(pinADConfigCharacteristic, data.Bytes())
  	return
  }
docs: // WritePinADConfig writes the pin A/D config mask for all pins