PKGBUILD/pkg/sensor/bme280.go

package sensor

import (
	"fmt"
	"sync"

	"github.com/d2r2/go-bsbmp"
	"github.com/d2r2/go-i2c"
	"github.com/d2r2/go-logger"
	uuid "github.com/satori/go.uuid"

	"github.com/volker-raschek/flucky/pkg/internal/format"
	"github.com/volker-raschek/flucky/pkg/types"
)

// BME280 is a sensor to measure humidity and temperature.
type BME280 struct {
	*types.Sensor
	mutex *sync.Mutex
}

// Read measured values
func (bme280 *BME280) Read() ([]*types.MeasuredValue, error) {

	// Lock multiple access
	bme280.mutex.Lock()
	defer bme280.mutex.Unlock()

	// Create new connection to i2c-bus on 1 line with address 0x76.
	// Use i2cdetect utility to find device address over the i2c-bus
	i2c, err := i2c.NewI2C(*bme280.I2CAddress, *bme280.I2CBus)
	if err != nil {
		return nil, err
	}
	defer i2c.Close()

	// Reduce loglevel
	for _, pkg := range []string{"bsbmp", "i2c"} {
		err = logger.ChangePackageLogLevel(pkg, logger.InfoLevel)
		if err != nil {
			return nil, fmt.Errorf("Failed to change package log level: %v", err)
		}
	}

	sensor, err := bsbmp.NewBMP(bsbmp.BME280, i2c)
	if err != nil {
		return nil, err
	}

	temperatureValue, err := sensor.ReadTemperatureC(bsbmp.ACCURACY_STANDARD)
	if err != nil {
		return nil, err
	}

	pressureValue, err := sensor.ReadPressurePa(bsbmp.ACCURACY_STANDARD)
	if err != nil {
		return nil, err
	}

	_, humidityValue, err := sensor.ReadHumidityRH(bsbmp.ACCURACY_STANDARD)
	if err != nil {
		return nil, err
	}

	measuredValues := []*types.MeasuredValue{
		{
			ID:        uuid.NewV4().String(),
			Value:     float64(humidityValue),
			ValueType: "humidity",
			Date:      format.FormatedTime(),
			SensorID:  bme280.ID,
		},
		{
			ID:        uuid.NewV4().String(),
			Value:     float64(pressureValue),
			ValueType: "pressure",
			Date:      format.FormatedTime(),
			SensorID:  bme280.ID,
		},
		{
			ID:        uuid.NewV4().String(),
			Value:     float64(temperatureValue),
			ValueType: "temperature",
			Date:      format.FormatedTime(),
			SensorID:  bme280.ID,
		},
	}

	return measuredValues, nil
}