code: func (r *Adaptor) ServoWrite(pin string, angle byte) (err error) {
  	sysfsPin, err := r.PWMPin(pin)
  	if err != nil {
  		return err
  	}
  
  	duty := uint32(gobot.FromScale(float64(angle), 0, 180) * float64(r.PiBlasterPeriod))
  	return sysfsPin.SetDutyCycle(duty)
  }
docs: // ServoWrite writes a servo signal to the specified pin