code: func (s *Adaptor) AnalogWrite(pin string, level byte) (err error) {
  	params := url.Values{
  		"params":       {fmt.Sprintf("%v,%v", pin, level)},
  		"access_token": {s.AccessToken},
  	}
  	url := fmt.Sprintf("%v/analogwrite", s.deviceURL())
  	_, err = s.request("POST", url, params)
  	return
  }
docs: // AnalogWrite writes analog pin with specified level using Particle cloud api