fix #327 always factory reset the GPS once

src/main.cpp

@@ -231,15 +231,18 @@ void setup()
 // If we know we have a L80 GPS, don't try UBLOX
 #ifndef L80_RESET
     // Init GPS - first try ublox
-    gps = new UBloxGPS();
+    auto ublox = new UBloxGPS();
+    gps = ublox;
     if (!gps->setup()) {
         DEBUG_MSG("ERROR: No UBLOX GPS found\n");
 
+        delete ublox;
+        gps = ublox = NULL;
+
         if (GPS::_serial_gps) {
             // Some boards might have only the TX line from the GPS connected, in that case, we can't configure it at all.  Just
             // assume NEMA at 9600 baud.
             DEBUG_MSG("Hoping that NEMA might work\n");
-            delete gps;
 
             // dumb NEMA access only work for serial GPSes)
             gps = new NEMAGPS();
@@ -255,6 +258,16 @@ void setup()
 
     service.init();
 
+    // We have now loaded our saved preferences from flash
+
+    // ONCE we will factory reset the GPS for bug #327
+    if (ublox && !devicestate.did_gps_reset) {
+        if (ublox->factoryReset()) { // If we don't succeed try again next time
+            devicestate.did_gps_reset = true;
+            nodeDB.saveToDisk();
+        }
+    }
+
 #ifdef SX1262_ANT_SW
     // make analog PA vs not PA switch on SX1262 eval board work properly
     pinMode(SX1262_ANT_SW, OUTPUT);