balazsgrill/wscgo

package devices

import (
    "periph.io/x/conn/v3/i2c/i2creg"
    "periph.io/x/devices/v3/ccs811"
)

// ICCS811 denotes a CCS811 environmental sensor
type ICCS811 interface {
    Device
    // ECO2 returns the sensor interface to the "equivalent CO2" measurement value
    ECO2() ISensor
    // VOC returns the sensor interface to the "Total Volatile Organic Compound" measuremenr value
    VOC() ISensor
}

// CCS811Config holds the configuration data of a sensor
type CCS811Config struct {
    Address  int    `ini:"address"`
    Bus      string `ini:"i2cbus"`
    Duration int    `ini:"duration"`
}

type ccs811Device struct {
    dev          *ccs811.Dev
    config       *CCS811Config
    eco2         BaseSensor
    voc          BaseSensor
    measureCount int
}

// CreateCCS811 configures connection the sensor
func CreateCCS811(config *CCS811Config) (ICCS811, error) {
    opts := &ccs811.Opts{
        Addr:               uint16(config.Address),
        MeasurementMode:    ccs811.MeasurementModeConstant1000,
        InterruptWhenReady: false,
        UseThreshold:       false,
    }

    bus, err := i2creg.Open(config.Bus)
    if err != nil {
        return nil, err
    }
    dev, err := ccs811.New(bus, opts)
    if err != nil {
        return nil, err
    }

    return &ccs811Device{
        dev:          dev,
        config:       config,
        measureCount: config.Duration,
        eco2: BaseSensor{
            VUnit: "ppm",
        },
        voc: BaseSensor{
            VUnit: "ppb",
        },
    }, nil
}

func (dev *ccs811Device) Tick() error {
    values := &ccs811.SensorValues{}
    if dev.measureCount == 0 {
        dev.measureCount = dev.config.Duration
        err := dev.dev.Sense(values)
        if err != nil {
            return err
        }
        (&dev.eco2).NotifyListeners(float64(values.ECO2))
        (&dev.voc).NotifyListeners(float64(values.VOC))
    } else {
        dev.measureCount--
    }
    return nil
}

func (dev *ccs811Device) Initialize() error {
    dev.measureCount = dev.config.Duration
    return nil
}

func (dev *ccs811Device) ECO2() ISensor {
    return &dev.eco2
}

func (dev *ccs811Device) VOC() ISensor {
    return &dev.voc
}