wip gps power fixes #376

.vscode/settings.json

@@ -57,6 +57,7 @@
         "HFSR",
         "Meshtastic",
         "NEMAGPS",
+        "NMEAGPS",
         "RDEF",
         "Ublox",
         "bkpt",

src/PowerFSM.cpp

@@ -91,7 +91,7 @@ static void lsIdle()
 static void lsExit()
 {
     // setGPSPower(true); // restore GPS power
-    gps->startLock();
+    gps->forceWake(true);
 }
 
 static void nbEnter()

src/gps/GPS.cpp

@@ -1,6 +1,7 @@
 
 #include "GPS.h"
 #include "configuration.h"
+#include "sleep.h"
 #include <assert.h>
 #include <time.h>
 
@@ -86,19 +87,99 @@ uint32_t getValidTime()
     return timeSetFromGPS ? getTime() : 0;
 }
 
+bool GPS::setup()
+{
+    notifySleepObserver.observe(&notifySleep);
+
+    return true;
+}
+
 /**
  * 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 GPS::setWantLocation(bool on)
+void GPS::setAwake(bool on)
 {
-    if (wantNewLocation != on) {
-        wantNewLocation = on;
+    if(!wakeAllowed && on) {
+        DEBUG_MSG("Inhibiting because !wakeAllowed\n");
+        on = false;
+    }
+
+    if (isAwake != on) {
         DEBUG_MSG("WANT GPS=%d\n", on);
         if (on)
             wake();
         else
             sleep();
+
+        isAwake = on;
+    }
+}
+
+void GPS::loop()
+{
+    if (whileIdle()) {
+        // if we have received valid NMEA claim we are connected
+        isConnected = true;
+    }
+
+    // If we are overdue for an update, turn on the GPS and at least publish the current status
+    uint32_t now = millis();
+    bool mustPublishUpdate = false;
+
+    if ((now - lastUpdateMsec) > 30 * 1000 && !isAwake) {
+        // We now want to be awake - so wake up the GPS
+        setAwake(true);
+
+        mustPublishUpdate =
+            true; // Even if we don't have an update this time, we at least want to occasionally publish the current state
+    }
+
+    // While we are awake
+    if (isAwake) {
+        DEBUG_MSG("looking for location\n");
+        bool gotTime = lookForTime();
+        bool gotLoc = lookForLocation();
+
+        if (gotLoc)
+            hasValidLocation = true;
+
+        mustPublishUpdate |= gotLoc;
+
+        // Once we get a location we no longer desperately want an update
+        if (gotLoc) {
+            lastUpdateMsec = now;
+            setAwake(false);
         }
-}
+    }
+
+    if (mustPublishUpdate) {
+        DEBUG_MSG("publishing GPS lock=%d\n", hasLock());
+
+        // Notify any status instances that are observing us
+        const meshtastic::GPSStatus status =
+            meshtastic::GPSStatus(hasLock(), isConnected, latitude, longitude, altitude, dop, heading, numSatellites);
+        newStatus.notifyObservers(&status);
+    }
+}
+
+void GPS::forceWake(bool on)
+{
+    if (on) {
+        DEBUG_MSG("Looking for GPS lock\n");
+        lastUpdateMsec = 0; // Force an update ASAP
+        wakeAllowed = true;
+    } else {
+        wakeAllowed = false;
+        setAwake(false);
+    }
+}
+
+/// Prepare the GPS for the cpu entering deep or light sleep, expect to be gone for at least 100s of msecs
+int GPS::prepareSleep(void *unused)
+{
+    forceWake(false);
+
+    return 0;
+}

src/gps/GPS.h

@@ -27,11 +27,18 @@ void readFromRTC();
  */
 class GPS
 {
-  protected:
+  private:
+    uint32_t lastUpdateMsec = 0;
+
     bool hasValidLocation = false; // default to false, until we complete our first read
 
-    bool wantNewLocation = false; // true if we want a location right now
+    bool isAwake = false; // true if we want a location right now
+
+    bool wakeAllowed = true; // false if gps must be forced to sleep regardless of what time it is
 
+    CallbackObserver<GPS, void *> notifySleepObserver = CallbackObserver<GPS, void *>(this, &GPS::prepareSleep);
+
+  protected:
   public:
     /** If !NULL we will use this serial port to construct our GPS */
     static HardwareSerial *_serial_gps;
@@ -48,40 +55,69 @@ class GPS
 
     bool isConnected = false; // Do we have a GPS we are talking to
 
-    virtual ~GPS() {}
+    virtual ~GPS() {} // FIXME, we really should unregister our sleep observer
 
     /** We will notify this observable anytime GPS state has changed meaningfully */
     Observable<const meshtastic::GPSStatus *> newStatus;
 
     /**
      * Returns true if we succeeded
      */
-    virtual bool setup() { return true; }
+    virtual bool setup();
 
-    /// A loop callback for subclasses that need it.  FIXME, instead just block on serial reads
-    virtual void loop() {}
+    virtual void loop();
 
     /// Returns ture if we have acquired GPS lock.
     bool hasLock() const { return hasValidLocation; }
 
     /**
-     * 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
+     * Restart our lock attempt - try to get and broadcast a GPS reading ASAP
+     * called after the CPU wakes from light-sleep state
+     *
+     * Or set to false, to disallow any sort of waking
+     * */
+    void forceWake(bool on);
+
+  protected:
+    /// If possible force the GPS into sleep/low power mode
+    virtual void sleep() {}
+
+    /// wake the GPS into normal operation mode
+    virtual void wake() {}
+
+    /** 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
      */
-    void setWantLocation(bool on);
+    virtual bool whileIdle() = 0;
 
     /**
-     * Restart our lock attempt - try to get and broadcast a GPS reading ASAP
-     * called after the CPU wakes from light-sleep state */
-    virtual void startLock() {}
+     * 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() = 0;
+
+    /**
+     * 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() = 0;
 
-protected:
-  /// If possible force the GPS into sleep/low power mode
-  virtual void sleep() {}
+  private:
+    /// Prepare the GPS for the cpu entering deep or light sleep, expect to be gone for at least 100s of msecs
+    /// always returns 0 to indicate okay to sleep
+    int prepareSleep(void *unused);
 
-  /// wake the GPS into normal operation mode
-  virtual void wake() {}
+    /**
+     * 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);
 };
 
 extern GPS *gps;