code: func NewAdaptor() *Adaptor {
  	r := &Adaptor{
  		mutex:           &sync.Mutex{},
  		name:            gobot.DefaultName("RaspberryPi"),
  		digitalPins:     make(map[int]*sysfs.DigitalPin),
  		pwmPins:         make(map[int]*PWMPin),
  		PiBlasterPeriod: 10000000,
  	}
  	content, _ := readFile()
  	for _, v := range strings.Split(string(content), "\n") {
  		if strings.Contains(v, "Revision") {
  			s := strings.Split(string(v), " ")
  			version, _ := strconv.ParseInt("0x"+s[len(s)-1], 0, 64)
  			r.i2cDefaultBus = 1
  			r.spiDefaultBus = 0
  			r.spiDefaultChip = 0
  			r.spiDefaultMode = 0
  			r.spiDefaultMaxSpeed = 500000
  			if version <= 3 {
  				r.revision = "1"
  				r.i2cDefaultBus = 0
  			} else if version <= 15 {
  				r.revision = "2"
  			} else {
  				r.revision = "3"
  			}
  		}
  	}
  
  	return r
  }
docs: // NewAdaptor creates a Raspi Adaptor