package sensor import ( "context" "fmt" "io/ioutil" "math" "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 } // GetSensor return the sensor struct func (s *DS18B20) GetSensor() *types.Sensor { return s.Sensor } // ReadTemperature measure the temperature func (s *DS18B20) ReadTemperature(round float64) (*types.Temperature, error) { 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 // round if round != 0 { temperatureValue = math.Round(temperatureValue/round) * round } temperature := &types.Temperature{ TemperatureID: uuid.NewV4().String(), TemperatureValue: temperatureValue, TemperatureFromDate: time.Now(), TemperatureTillDate: time.Now(), SensorID: s.SensorID, } return temperature, nil } // ReadTemperatureWriteIntoChannel and write values into a channel func (s *DS18B20) ReadTemperatureWriteIntoChannel(round float64, temperatureChannel chan<- *types.Temperature, errorChannel chan<- error, wg *sync.WaitGroup) { if wg != nil { defer wg.Done() } temperature, err := s.ReadTemperature(round) if err != nil { errorChannel <- err return } temperatureChannel <- temperature } // ReadTemperatureContinously into a channel until context closed func (s *DS18B20) ReadTemperatureContinously(ctx context.Context, round float64, temperatureChannel chan<- *types.Temperature, errorChannel chan<- error) { for { select { case <-ctx.Done(): errorChannel <- fmt.Errorf("%v: Context closed: %v", s.SensorName, ctx.Err()) return default: s.ReadTemperatureWriteIntoChannel(round, temperatureChannel, errorChannel, nil) } } }