From f6861a8fe27130c19895c61262026d53831cda6d Mon Sep 17 00:00:00 2001
From: Kevin Hester <kevinh@geeksville.com>
Date: Tue, 6 Oct 2020 06:07:30 +0800
Subject: [PATCH] bug #376 wip - we now minimize comms to gps to save power

---
 platformio.ini       |  2 +-
 src/gps/GPS.cpp      |  5 ++++-
 src/gps/GPS.h        |  6 +++---
 src/gps/UBloxGPS.cpp | 27 ++++++++++++++++-----------
 src/main.cpp         |  2 +-
 5 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/platformio.ini b/platformio.ini
index 74ed94ab..035a8e29 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -62,7 +62,7 @@ lib_deps =
   1260 ; OneButton library for non-blocking button debounce
   1202 ; CRC32, explicitly needed because dependency is missing in the ble ota update lib
   https://github.com/meshtastic/arduino-fsm.git 
-  https://github.com/meshtastic/SparkFun_Ublox_Arduino_Library.git
+  https://github.com/meshtastic/SparkFun_Ublox_Arduino_Library.git#cb8353dfddd1b0e205098f5e70d5f2a5f74b4838
   https://github.com/meshtastic/RadioLib.git#ac7feac00f5e0bd95a3ac5d5852b4cc7344cf95c
   https://github.com/meshtastic/TinyGPSPlus.git 
   https://github.com/meshtastic/AXP202X_Library.git#8404abb6d4b486748636bc6ad72d2a47baaf5460
diff --git a/src/gps/GPS.cpp b/src/gps/GPS.cpp
index 2f8e636e..f8d83743 100644
--- a/src/gps/GPS.cpp
+++ b/src/gps/GPS.cpp
@@ -209,7 +209,10 @@ void GPS::loop()
     // While we are awake
     if (isAwake) {
         // DEBUG_MSG("looking for location\n");
-        whileActive();
+        if ((now - lastWhileActiveMsec) > 1000) {
+            lastWhileActiveMsec = now;
+            whileActive();
+        }
 
         // If we've already set time from the GPS, no need to ask the GPS
         bool gotTime = timeSetFromGPS || lookForTime();
diff --git a/src/gps/GPS.h b/src/gps/GPS.h
index 3a7279c2..1f8429a4 100644
--- a/src/gps/GPS.h
+++ b/src/gps/GPS.h
@@ -28,7 +28,7 @@ void readFromRTC();
 class GPS
 {
   private:
-    uint32_t lastWakeStartMsec = 0, lastSleepStartMsec = 0;
+    uint32_t lastWakeStartMsec = 0, lastSleepStartMsec = 0, lastWhileActiveMsec = 0;
 
     bool hasValidLocation = false; // default to false, until we complete our first read
 
@@ -94,7 +94,7 @@ class GPS
      */
     virtual bool whileIdle() = 0;
 
-    /** Idle processing while GPS is looking for lock */
+    /** Idle processing while GPS is looking for lock, called once per secondish */
     virtual void whileActive() {}
 
     /**
@@ -134,7 +134,7 @@ class GPS
     uint32_t getSleepTime() const;
 
     GpsOperation getGpsOp() const;
-    
+
     /**
      * Tell users we have new GPS readings
      */
diff --git a/src/gps/UBloxGPS.cpp b/src/gps/UBloxGPS.cpp
index e34513d2..887fd62b 100644
--- a/src/gps/UBloxGPS.cpp
+++ b/src/gps/UBloxGPS.cpp
@@ -34,7 +34,8 @@ bool UBloxGPS::setupGPS()
         // _serial_gps.setRxBufferSize(1024); // the default is 256
     }
 
-    ublox.enableDebugging(Serial);
+    // uncomment to see debug info
+    // ublox.enableDebugging(Serial);
 
     // try a second time, the ublox lib serial parsing is buggy?
     // see https://github.com/meshtastic/Meshtastic-device/issues/376
@@ -112,9 +113,19 @@ bool UBloxGPS::factoryReset()
 /** Idle processing while GPS is looking for lock */
 void UBloxGPS::whileActive()
 {
-    // If we don't have a fix (a quick check), don't try waiting for a solution)
-    fixType = ublox.getFixType(maxWait());
-    DEBUG_MSG("GPS fix type %d\n", fixType);
+    ublox.getT(maxWait()); // ask for new time data - hopefully ready when we come back
+
+    // Ask for a new position fix - hopefully it will have results ready by next time
+    // the order here is important, because we only check for has latitude when reading
+    ublox.getSIV(maxWait());
+    ublox.getPDOP(maxWait());
+    ublox.getP(maxWait());
+
+    // Update fixtype
+    if (ublox.moduleQueried.fixType) {
+        fixType = ublox.getFixType(0);
+        DEBUG_MSG("GPS fix type %d\n", fixType);
+    }
 }
 
 /**
@@ -141,8 +152,6 @@ bool UBloxGPS::lookForTime()
             t.tm_isdst = false;
             perhapsSetRTC(t);
             return true;
-        } else {
-            ublox.getT(maxWait()); // ask for new time data - hopefully ready when we come back
         }
     }
 
@@ -177,11 +186,6 @@ bool UBloxGPS::lookForLocation()
             // Also: apparently when the GPS is initially reporting lock it can output a bogus latitude > 90 deg!
             foundLocation =
                 (latitude != 0) && (longitude != 0) && (latitude <= 900000000 && latitude >= -900000000) && (numSatellites > 0);
-        } else {
-            // Ask for a new position fix - hopefully it will have results ready by next time
-            ublox.getSIV(maxWait());
-            ublox.getPDOP(maxWait());
-            ublox.getP(maxWait());
         }
     }
 
@@ -205,6 +209,7 @@ void UBloxGPS::sleep()
 
 void UBloxGPS::wake()
 {
+    fixType = 0; // assume we hace no fix yet
     setGPSPower(true);
     // Give time for the GPS to boot
     delay(200);
diff --git a/src/main.cpp b/src/main.cpp
index 424d9f4a..f4e811f5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -429,7 +429,7 @@ void loop()
 
     // FIXME - until button press handling is done by interrupt (see polling above) we can't sleep very long at all or buttons
     // feel slow
-    msecstosleep = 200; // FIXME, stop early if something happens
+    msecstosleep = 10; // FIXME, stop early if something happens and sleep much longer
 
     // TODO: This should go into a thread handled by FreeRTOS.
     handleWebResponse();