espurna-mirror/code/espurna/sensors/BaseSensor.h

// -----------------------------------------------------------------------------
// Abstract sensor class (other sensor classes extend this class)
// Copyright (C) 2017-2019 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------

#pragma once

#include <Arduino.h>
#include "../espurna.h"
#include "../sensor.h"

#include <cstddef>
#include <cstdint>
#include <functional>

// TODO: const'ify accessors. since these are virtuals, *every* implementing class would be affected
// (...so, it would be time for a pretty big changeset...)

class BaseSensor {
public:
    // Pin this to the resulting object (poor man's rtti) so we know what it can be static_cast'ed into
    struct ClassKind {
        ClassKind() :
            _value(_last)
        {
            ++_last;
        }

        int value() const {
            return _value;
        }

        bool operator==(const ClassKind& other) const {
            return _value == other._value;
        }

    private:
        static int _last;
        int _value;
    };

    static const ClassKind Kind;

    // Generic way to pass the sensor instance to the isr
    struct InterruptablePin {
        InterruptablePin() = default;
        ~InterruptablePin() {
            detach();
        }

        template <typename T, typename TypedCallback = void(*)(T*)>
        void attach(T* instance, TypedCallback callback, int mode) {
            _attach(static_cast<void*>(instance), reinterpret_cast<VoidCallback>(callback), mode);
        }

        InterruptablePin& operator=(unsigned char pin) {
            _pin = pin;
            return *this;
        }

        bool operator==(unsigned char other) const {
            return _pin == other;
        }

        explicit operator String() const {
            return String(_pin);
        }

        void detach() {
            gpioUnlock(_current);
            ::detachInterrupt(_current);
            _current = GPIO_NONE;
        }

        void pin(unsigned char value) {
            _pin = value;
        }

        unsigned char pin() const {
            return _pin;
        }

    private:
        using VoidCallback = void(*)(void*);

        void _attach(void* instance, VoidCallback callback, int mode) {
            if (_current != _pin) {
                if (!gpioLock(_pin)) {
                    return;
                }

                detach();
                ::attachInterruptArg(_pin, callback, instance, mode);

                _current = _pin;
            }
        }

        unsigned char _current { GPIO_NONE };
        unsigned char _pin { GPIO_NONE };
    };

    // Generic container for magnitude types used in the sensor
    struct Magnitude {
        unsigned char type;
#if __cplusplus <= 201103L
        constexpr Magnitude(unsigned char type) :
            type(type)
        {}
#endif
    };

    template <typename T, typename Callback>
    static void findMagnitudes(const T& container, unsigned char type, Callback&& callback) {
        auto begin = std::begin(container);
        auto end = std::end(container);

        for (auto it = begin; it != end; ++it) {
            if ((*it).type == type) {
                callback(std::distance(begin, it));
            }
        }
    }

    // Make sure we are correctly implementing an abstract base class
    BaseSensor() = default;
    virtual ~BaseSensor() = default;

    // Can't copy as base, should not happen
    BaseSensor(const BaseSensor&) = delete;
    BaseSensor(BaseSensor&&) = delete;

    BaseSensor& operator=(const BaseSensor&) = delete;
    BaseSensor& operator=(BaseSensor&&) = delete;

    // Initialization method, must be idempotent
    virtual void begin() {
    }

    // Suspend / resume sensor operation
    virtual void suspend() {
    }

    virtual void resume() {
    }

    // Custom hook (usually to update sensor state outside of normal methods)
    virtual void notify() {
    }

    // Loop-like method, call it in your main loop
    virtual void tick() {
    }

    // Pre-read hook (usually to populate registers with up-to-date data)
    virtual void pre() {
    }

    // Post-read hook (usually to reset things)
    virtual void post() {
    }

    // Generic calibration
    virtual void calibrate() {
    }

    // Number of decimals for a unit (or -1 for default)
    virtual signed char decimals(espurna::sensor::Unit) const {
        return -1;
    }

    // Kind of sensor
    virtual ClassKind kind() const {
        return Kind;
    }

    // Sensor ID, must be unique
    virtual unsigned char id() const = 0;

    // Number of available value slots
    virtual unsigned char count() const = 0;

    // Descriptive name of the sensor
    virtual String description() const = 0;

    // Descriptive name of the slot # index
    virtual String description(unsigned char) const {
        return description();
    }

    // Address of the sensor (it could be the GPIO or I2C address)
    virtual String address(unsigned char index) const = 0;

    // Type for slot # index
    virtual unsigned char type(unsigned char index) const = 0;

    // Unit of the slot # index
    virtual espurna::sensor::Unit units(unsigned char index) const {
        using namespace espurna::sensor;

        switch (type(index)) {
        case MAGNITUDE_TEMPERATURE:
            return Unit::Celcius;
        case MAGNITUDE_HUMIDITY:
        case MAGNITUDE_POWER_FACTOR:
            return Unit::Percentage;
        case MAGNITUDE_PRESSURE:
            return Unit::Hectopascal;
        case MAGNITUDE_CURRENT:
            return Unit::Ampere;
        case MAGNITUDE_VOLTAGE:
            return Unit::Volt;
        case MAGNITUDE_POWER_ACTIVE:
            return Unit::Watt;
        case MAGNITUDE_POWER_APPARENT:
            return Unit::Voltampere;
        case MAGNITUDE_POWER_REACTIVE:
            return Unit::VoltampereReactive;
        case MAGNITUDE_ENERGY_DELTA:
            return Unit::Joule;
        case MAGNITUDE_ENERGY:
            return Unit::KilowattHour;
        case MAGNITUDE_PM1DOT0:
        case MAGNITUDE_PM2DOT5:
        case MAGNITUDE_PM10:
        case MAGNITUDE_TVOC:
        case MAGNITUDE_CH2O:
            return Unit::MicrogrammPerCubicMeter;
        case MAGNITUDE_CO:
        case MAGNITUDE_CO2:
        case MAGNITUDE_NO2:
        case MAGNITUDE_VOC:
            return Unit::PartsPerMillion;
        case MAGNITUDE_LUX:
            return Unit::Lux;
        case MAGNITUDE_RESISTANCE:
            return Unit::Ohm;
        case MAGNITUDE_HCHO:
            return Unit::MilligrammPerCubicMeter;
        case MAGNITUDE_GEIGER_CPM:
            return Unit::CountsPerMinute;
        case MAGNITUDE_GEIGER_SIEVERT:
            return Unit::MicrosievertPerHour;
        case MAGNITUDE_DISTANCE:
            return Unit::Meter;
        case MAGNITUDE_FREQUENCY:
            return Unit::Hertz;
        case MAGNITUDE_PH:
            return Unit::Ph;
        default:
            break;
        }

        return Unit::None;
    }

    // Current value for slot # index
    virtual double value(unsigned char index) = 0;

    // Return ready status (true if ready to be read)
    bool ready() const {
        return _ready;
    }

    // Return sensor last internal error
    int error() const {
        return _error;
    }

protected:
    int _error = SENSOR_ERROR_OK;
    bool _dirty = true;
    bool _ready = false;
};

int BaseSensor::ClassKind::_last { 0 };
const BaseSensor::ClassKind BaseSensor::Kind;