firmware/src/modules/Telemetry/Sensor/SEN5XSensor.h

#include "configuration.h"

#if !MESHTASTIC_EXCLUDE_AIR_QUALITY_SENSOR

#include "../detect/ReClockI2C.h"
#include "../mesh/generated/meshtastic/telemetry.pb.h"
#include "RTC.h"
#include "TelemetrySensor.h"
#include "Wire.h"

// Warm up times for SEN5X from the datasheet
#ifndef SEN5X_WARMUP_MS_1
#define SEN5X_WARMUP_MS_1 15000
#endif

#ifndef SEN5X_WARMUP_MS_2
#define SEN5X_WARMUP_MS_2 30000
#endif

#ifndef SEN5X_POLL_INTERVAL
#define SEN5X_POLL_INTERVAL 1000
#endif

#ifndef SEN5X_I2C_CLOCK_SPEED
#define SEN5X_I2C_CLOCK_SPEED 100000
#endif

/*
Time after which the sensor can go to sleep, as the warmup period has passed
and the VOCs sensor will is allowed to stop (although needs to recover the state
each time)
*/
#ifndef SEN5X_VOC_STATE_WARMUP_S
/* Note for Testing 5' is enough
Sensirion recommends 1h
This can be bypassed completely if switching to low-power RHT/Gas mode and setting
SEN5X_VOC_STATE_WARMUP_S 0
*/
#define SEN5X_VOC_STATE_WARMUP_S 3600
#endif

#define ONE_WEEK_IN_SECONDS 604800

struct _SEN5XMeasurements {
    uint16_t pM1p0;
    uint16_t pM2p5;
    uint16_t pM4p0;
    uint16_t pM10p0;
    uint32_t pN0p5;
    uint32_t pN1p0;
    uint32_t pN2p5;
    uint32_t pN4p0;
    uint32_t pN10p0;
    float tSize;
    float humidity;
    float temperature;
    float vocIndex;
    float noxIndex;
};

class SEN5XSensor : public TelemetrySensor
{
  private:
    TwoWire *_bus{};
    uint8_t _address{};
#ifdef SEN5X_I2C_CLOCK_SPEED
    ScanI2C::I2CPort _port = ScanI2C::I2CPort::NO_I2C;
    ReClockI2C reClockI2C;
#endif

    bool getVersion();
    float firmwareVer = -1;
    float hardwareVer = -1;
    float protocolVer = -1;
    bool findModel();

// Commands
#define SEN5X_RESET 0xD304
#define SEN5X_GET_PRODUCT_NAME 0xD014
#define SEN5X_GET_FIRMWARE_VERSION 0xD100
#define SEN5X_START_MEASUREMENT 0x0021
#define SEN5X_START_MEASUREMENT_RHT_GAS 0x0037
#define SEN5X_STOP_MEASUREMENT 0x0104
#define SEN5X_READ_DATA_READY 0x0202
#define SEN5X_START_FAN_CLEANING 0x5607
#define SEN5X_RW_VOCS_STATE 0x6181

#define SEN5X_READ_VALUES 0x03C4
#define SEN5X_READ_RAW_VALUES 0x03D2
#define SEN5X_READ_PM_VALUES 0x0413

#define SEN5X_VOC_VALID_TIME 600
#define SEN5X_VOC_VALID_DATE 1514764800

    enum SEN5Xmodel { SEN5X_UNKNOWN = 0, SEN50 = 0b001, SEN54 = 0b010, SEN55 = 0b100 };
    SEN5Xmodel model = SEN5X_UNKNOWN;

    enum SEN5XState {
        SEN5X_OFF,
        SEN5X_IDLE,
        SEN5X_RHTGAS_ONLY,
        SEN5X_MEASUREMENT,
        SEN5X_MEASUREMENT_2,
        SEN5X_CLEANING,
        SEN5X_NOT_DETECTED
    };
    SEN5XState state = SEN5X_OFF;
    // Flag to work on one-shot (read and sleep), or continuous mode
    bool oneShotMode = true;
    void setMode(bool setOneShot);
    bool vocStateValid();
/* Sensirion recommends taking a reading after 15 seconds,
if the Particle number reading is over 100#/cm3 the reading is OK,
but if it is lower wait until 30 seconds and take it again.
See: https://sensirion.com/resource/application_note/low_power_mode/sen5x
*/
#define SEN5X_PN4P0_CONC_THD 100

    bool sendCommand(uint16_t command);
    bool sendCommand(uint16_t command, uint8_t *buffer, uint8_t byteNumber = 0);
    uint8_t readBuffer(uint8_t *buffer, uint8_t byteNumber); // Return number of bytes received
    uint8_t sen5xCRC(const uint8_t *buffer);
    bool startCleaning();
    uint8_t getMeasurements();
    // bool readRawValues();
    bool readPNValues(bool cumulative);
    bool readValues();

    uint32_t pmMeasureStarted = 0;
    uint32_t rhtGasMeasureStarted = 0;
    uint32_t lastDataPoll = 0;
    _SEN5XMeasurements sen5xmeasurement{};

    bool idle(bool checkState = true);

  protected:
    // Store status of the sensor in this file
    const char *sen5XStateFileName = "/prefs/sen5X.dat";
    meshtastic_SEN5XState sen5xstate = meshtastic_SEN5XState_init_zero;

    bool loadState();
    bool saveState();

    // Cleaning State
    uint32_t lastCleaning = 0;
    bool lastCleaningValid = false;

// VOC State
#define SEN5X_VOC_STATE_BUFFER_SIZE 8
    uint8_t vocState[SEN5X_VOC_STATE_BUFFER_SIZE]{};
    uint32_t vocTime = 0;
    bool vocValid = false;

    bool vocStateFromSensor();
    bool vocStateToSensor();
    bool vocStateStable();
    bool vocStateRecent(uint32_t now);

  public:
    SEN5XSensor();
    bool probe(TwoWire *bus, uint8_t address, ScanI2C::I2CPort port);
    virtual bool initDevice(TwoWire *bus, ScanI2C::FoundDevice *dev) override;
    virtual bool getMetrics(meshtastic_Telemetry *measurement) override;

    virtual bool isActive() override;
    virtual void sleep() override;
    virtual uint32_t wakeUp() override;
    virtual bool canSleep() override { return true; }
    virtual int32_t wakeUpTimeMs() override;
    virtual int32_t pendingForReadyMs() override;

    AdminMessageHandleResult handleAdminMessage(const meshtastic_MeshPacket &mp, meshtastic_AdminMessage *request,
                                                meshtastic_AdminMessage *response) override;
};

#endif