package sensor import ( "context" "fmt" "io/ioutil" "path/filepath" "strconv" "strings" "sync" "time" "github.com/go-flucky/flucky/pkg/types" uuid "github.com/satori/go.uuid" ) // DS18B20 is a sensor to measure humidity and temperature. type DS18B20 struct { *types.Sensor } // GetSensorModel returns the sensor model func (s *DS18B20) GetSensorModel() types.SensorModel { return s.Sensor.SensorModel } // Read measured values func (s *DS18B20) Read() ([]types.MeasuredValue, error) { if s.WireID == nil { return nil, fmt.Errorf("WireID is not specified for sensor %v", s.Name()) } data, err := ioutil.ReadFile(filepath.Join("/sys/bus/w1/devices", *s.WireID, "/w1_slave")) if err != nil { return nil, fmt.Errorf("Can not read data from sensor %v", s.SensorName) } raw := string(data) i := strings.LastIndex(raw, "t=") if i == -1 { return nil, ErrReadSensor } c, err := strconv.ParseFloat(raw[i+2:len(raw)-1], 64) if err != nil { return nil, ErrParseData } temperatureValue := c / 1000 measuredValues := []types.MeasuredValue{ &types.Temperature{ TemperatureID: uuid.NewV4().String(), TemperatureValue: temperatureValue, TemperatureFromDate: time.Now(), TemperatureTillDate: time.Now(), SensorID: s.SensorID, }, } return measuredValues, nil } // ReadChannel reads the measured values from the sensor and writes them to a // channel. func (s *DS18B20) ReadChannel(measuredValuesChannel chan<- []types.MeasuredValue, errorChannel chan<- error, wg *sync.WaitGroup) { if wg != nil { defer wg.Done() } measuredValues, err := s.Read() if err != nil { errorChannel <- err return } measuredValuesChannel <- measuredValues } // ReadContinously reads the measured values continously from the sensor and // writes them to a channel. func (s *DS18B20) ReadContinously(ctx context.Context, measuredValuesChannel chan<- []types.MeasuredValue, errorChannel chan<- error) { for { select { case <-ctx.Done(): errorChannel <- fmt.Errorf("%v: Context closed: %v", s.SensorName, ctx.Err()) return default: s.ReadChannel(measuredValuesChannel, errorChannel, nil) } } }