firmware/src/gps/GPS.h

#pragma once

#include "GPSStatus.h"
#include "Observer.h"
#include "TinyGPS++.h"
#include "concurrency/OSThread.h"
#include "input/RotaryEncoderInterruptImpl1.h"
#include "input/UpDownInterruptImpl1.h"
#include "modules/PositionModule.h"

// Allow defining the polarity of the ENABLE output.  default is active high
#ifndef GPS_EN_ACTIVE
#define GPS_EN_ACTIVE 1
#endif

struct uBloxGnssModelInfo {
    char swVersion[30];
    char hwVersion[10];
    uint8_t extensionNo;
    char extension[10][30];
};

typedef enum { GNSS_MODEL_MTK, GNSS_MODEL_UBLOX, GNSS_MODEL_UC6580, GNSS_MODEL_UNKNOWN, GNSS_MODEL_MTK_L76B } GnssModel_t;

typedef enum {
    GNSS_RESPONSE_NONE,
    GNSS_RESPONSE_NAK,
    GNSS_RESPONSE_FRAME_ERRORS,
    GNSS_RESPONSE_OK,
} GPS_RESPONSE;

// Generate a string representation of DOP
const char *getDOPString(uint32_t dop);

/**
 * A gps class that only reads from the GPS periodically (and FIXME - eventually keeps the gps powered down except when reading)
 *
 * When new data is available it will notify observers.
 */
class GPS : private concurrency::OSThread
{
    TinyGPSPlus reader;
    uint8_t fixQual = 0; // fix quality from GPGGA
    uint32_t lastChecksumFailCount = 0;

#ifndef TINYGPS_OPTION_NO_CUSTOM_FIELDS
    // (20210908) TinyGps++ can only read the GPGSA "FIX TYPE" field
    // via optional feature "custom fields", currently disabled (bug #525)
    TinyGPSCustom gsafixtype; // custom extract fix type from GPGSA
    TinyGPSCustom gsapdop;    // custom extract PDOP from GPGSA
    uint8_t fixType = 0;      // fix type from GPGSA
#endif
  private:
    uint32_t lastWakeStartMsec = 0, lastSleepStartMsec = 0;
    const int serialSpeeds[6] = {9600, 4800, 38400, 57600, 115200, 9600};

    uint32_t rx_gpio = 0;
    uint32_t tx_gpio = 0;
    uint32_t en_gpio = 0;
    int32_t averageLockTime = 0;
    uint32_t GPSCycles = 0;

    int speedSelect = 0;
    int probeTries = 2;

    /**
     * hasValidLocation - indicates that the position variables contain a complete
     *   GPS location, valid and fresh (< gps_update_interval + position_broadcast_secs)
     */
    bool hasValidLocation = false; // default to false, until we complete our first read

    bool isAwake = false; // true if we want a location right now

    bool isInPowersave = false;

    bool shouldPublish = false; // If we've changed GPS state, this will force a publish the next loop()

    bool hasGPS = false; // Do we have a GPS we are talking to

    bool GPSInitFinished = false; // Init thread finished?
    bool GPSInitStarted = false;  // Init thread finished?

    uint8_t numSatellites = 0;

    CallbackObserver<GPS, void *> notifyDeepSleepObserver = CallbackObserver<GPS, void *>(this, &GPS::prepareDeepSleep);
    CallbackObserver<GPS, void *> notifyGPSSleepObserver = CallbackObserver<GPS, void *>(this, &GPS::prepareDeepSleep);

  public:
    /** If !NULL we will use this serial port to construct our GPS */
#if defined(RPI_PICO_WAVESHARE)
    static SerialUART *_serial_gps;
#else
    static HardwareSerial *_serial_gps;
#endif
    static uint8_t _message_PMREQ[];
    static uint8_t _message_PMREQ_10[];
    static const uint8_t _message_CFG_RXM_PSM[];
    static const uint8_t _message_CFG_RXM_ECO[];
    static const uint8_t _message_CFG_PM2[];
    static const uint8_t _message_GNSS_7[];
    static const uint8_t _message_GNSS_8[];
    static const uint8_t _message_JAM_6_7[];
    static const uint8_t _message_JAM_8[];
    static const uint8_t _message_NAVX5[];
    static const uint8_t _message_NAVX5_8[];
    static const uint8_t _message_NMEA[];
    static const uint8_t _message_DISABLE_TXT_INFO[];
    static const uint8_t _message_1HZ[];
    static const uint8_t _message_GLL[];
    static const uint8_t _message_GSA[];
    static const uint8_t _message_GSV[];
    static const uint8_t _message_VTG[];
    static const uint8_t _message_RMC[];
    static const uint8_t _message_AID[];
    static const uint8_t _message_GGA[];
    static const uint8_t _message_PMS[];
    static const uint8_t _message_SAVE[];

    // VALSET Commands for M10
    static const uint8_t _message_VALSET_PM[];
    static const uint8_t _message_VALSET_PM_RAM[];
    static const uint8_t _message_VALSET_PM_BBR[];
    static const uint8_t _message_VALSET_ITFM_RAM[];
    static const uint8_t _message_VALSET_ITFM_BBR[];
    static const uint8_t _message_VALSET_DISABLE_NMEA_RAM[];
    static const uint8_t _message_VALSET_DISABLE_NMEA_BBR[];
    static const uint8_t _message_VALSET_DISABLE_TXT_INFO_RAM[];
    static const uint8_t _message_VALSET_DISABLE_TXT_INFO_BBR[];
    static const uint8_t _message_VALSET_ENABLE_NMEA_RAM[];
    static const uint8_t _message_VALSET_ENABLE_NMEA_BBR[];
    static const uint8_t _message_VALSET_DISABLE_SBAS_RAM[];
    static const uint8_t _message_VALSET_DISABLE_SBAS_BBR[];

    meshtastic_Position p = meshtastic_Position_init_default;

    GPS() : concurrency::OSThread("GPS") {}

    virtual ~GPS();

    /** We will notify this observable anytime GPS state has changed meaningfully */
    Observable<const meshtastic::GPSStatus *> newStatus;

    /**
     * Returns true if we succeeded
     */
    virtual bool setup();

    // re-enable the thread
    void enable();

    // Disable the thread
    int32_t disable() override;

    // toggle between enabled/disabled
    void toggleGpsMode();

    void setGPSPower(bool on, bool standbyOnly, uint32_t sleepTime);

    /// Returns true if we have acquired GPS lock.
    virtual bool hasLock();

    /// Returns true if there's valid data flow with the chip.
    virtual bool hasFlow();

    /// Return true if we are connected to a GPS
    bool isConnected() const { return hasGPS; }

    bool isPowerSaving() const { return config.position.gps_mode != meshtastic_Config_PositionConfig_GpsMode_ENABLED; }

    // Empty the input buffer as quickly as possible
    void clearBuffer();

    // Create a ublox packet for editing in memory
    uint8_t makeUBXPacket(uint8_t class_id, uint8_t msg_id, uint8_t payload_size, const uint8_t *msg);

    // scratch space for creating ublox packets
    uint8_t UBXscratch[250] = {0};

    int rebootsSeen = 0;

    int getACK(uint8_t *buffer, uint16_t size, uint8_t requestedClass, uint8_t requestedID, uint32_t waitMillis);
    GPS_RESPONSE getACK(uint8_t c, uint8_t i, uint32_t waitMillis);
    GPS_RESPONSE getACK(const char *message, uint32_t waitMillis);

    /**
     * Switch the GPS into a mode where we are actively looking for a lock, or alternatively switch GPS into a low power mode
     *
     * calls sleep/wake
     */
    void setAwake(bool on);
    virtual bool factoryReset();

    // Creates an instance of the GPS class.
    // Returns the new instance or null if the GPS is not present.
    static GPS *createGps();

  protected:
    /**
     * Perform any processing that should be done only while the GPS is awake and looking for a fix.
     * Override this method to check for new locations
     *
     * @return true if we've acquired a time
     */

    /**
     * Perform any processing that should be done only while the GPS is awake and looking for a fix.
     * Override this method to check for new locations
     *
     * @return true if we've acquired a new location
     */

    /// Record that we have a GPS
    void setConnected();

    /** Subclasses should look for serial rx characters here and feed it to their GPS parser
     *
     * Return true if we received a valid message from the GPS
     */
    virtual bool whileIdle();

    /**
     * Perform any processing that should be done only while the GPS is awake and looking for a fix.
     * Override this method to check for new locations
     *
     * @return true if we've acquired a time
     */
    virtual bool lookForTime();

    /**
     * Perform any processing that should be done only while the GPS is awake and looking for a fix.
     * Override this method to check for new locations
     *
     * @return true if we've acquired a new location
     */
    virtual bool lookForLocation();

  private:
    /// Prepare the GPS for the cpu entering deep sleep, expect to be gone for at least 100s of msecs
    /// always returns 0 to indicate okay to sleep
    int prepareDeepSleep(void *unused);

    // Calculate checksum
    void UBXChecksum(uint8_t *message, size_t length);

    /** Get how long we should stay looking for each aquisition
     */
    uint32_t getWakeTime() const;

    /** Get how long we should sleep between aqusition attempts
     */
    uint32_t getSleepTime() const;

    /**
     * Tell users we have new GPS readings
     */
    void publishUpdate();

    virtual int32_t runOnce() override;

    // Get GNSS model
    String getNMEA();
    GnssModel_t probe(int serialSpeed);

    // delay counter to allow more sats before fixed position stops GPS thread
    uint8_t fixeddelayCtr = 0;

  protected:
    GnssModel_t gnssModel = GNSS_MODEL_UNKNOWN;
};

extern GPS *gps;