From 2bf7ea227101284ce58e1c916ab1205c554ff8aa Mon Sep 17 00:00:00 2001
From: Corvus Corax <corvuscorax@cybertrench.com>
Date: Sat, 23 Apr 2011 16:49:07 +0200
Subject: [PATCH] Modules/GPS: Make code to deal with home location optional to
 allow a sleeker GPS module for RAM challenged systems

---
 flight/Modules/GPS/GPS.c                  | 21 ++++++++++++++++++---
 flight/OpenPilot/System/inc/pios_config.h |  3 +++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/flight/Modules/GPS/GPS.c b/flight/Modules/GPS/GPS.c
index 7878e90dd..d649de994 100644
--- a/flight/Modules/GPS/GPS.c
+++ b/flight/Modules/GPS/GPS.c
@@ -53,8 +53,11 @@
 // Private functions
 
 static void gpsTask(void *parameters);
+
+#ifdef PIOS_GPS_SETS_HOMELOCATION
 static void setHomeLocation(GPSPositionData * gpsData);
 static float GravityAccel(float latitude, float longitude, float altitude);
+#endif
 
 // ****************
 // Private constants
@@ -65,11 +68,19 @@ static float GravityAccel(float latitude, float longitude, float altitude);
 #define GPS_TIMEOUT_MS                  500
 #define GPS_COMMAND_RESEND_TIMEOUT_MS   2000
 
+#ifdef PIOS_GPS_SETS_HOMELOCATION
 // Unfortunately need a good size stack for the WMM calculation
-#ifdef ENABLE_GPS_BINARY_GTOP
-	#define STACK_SIZE_BYTES            800
+	#ifdef ENABLE_GPS_BINARY_GTOP
+		#define STACK_SIZE_BYTES            800
+	#else
+		#define STACK_SIZE_BYTES            800
+	#endif
 #else
-	#define STACK_SIZE_BYTES            800
+	#ifdef ENABLE_GPS_BINARY_GTOP
+		#define STACK_SIZE_BYTES            440
+	#else
+		#define STACK_SIZE_BYTES            440
+	#endif
 #endif
 
 #define TASK_PRIORITY                   (tskIDLE_PRIORITY + 1)
@@ -311,12 +322,14 @@ static void gpsTask(void *parameters)
 		else
 		{	// we appear to be receiving GPS sentences OK, we've had an update
 
+#ifdef PIOS_GPS_SETS_HOMELOCATION
 			HomeLocationData home;
 			HomeLocationGet(&home);
 
 			GPSPositionGet(&GpsData);
 			if ((GpsData.Status == GPSPOSITION_STATUS_FIX3D) && (home.Set == HOMELOCATION_SET_FALSE))
 				setHomeLocation(&GpsData);
+#endif
 
 			//criteria for GPS-OK taken from this post...
 			//http://forums.openpilot.org/topic/1523-professors-insgps-in-svn/page__view__findpost__p__5220
@@ -334,6 +347,7 @@ static void gpsTask(void *parameters)
 	}
 }
 
+#ifdef PIOS_GPS_SETS_HOMELOCATION
 /*
  * Estimate the acceleration due to gravity for a particular location in LLA
  */
@@ -389,6 +403,7 @@ static void setHomeLocation(GPSPositionData * gpsData)
 		}
 	}
 }
+#endif
 
 // ****************
 
diff --git a/flight/OpenPilot/System/inc/pios_config.h b/flight/OpenPilot/System/inc/pios_config.h
index 3f4b1e706..454da36d7 100644
--- a/flight/OpenPilot/System/inc/pios_config.h
+++ b/flight/OpenPilot/System/inc/pios_config.h
@@ -89,6 +89,9 @@
 /* Stabilization options */
 #define PIOS_QUATERNION_STABILIZATION
 
+/* GPS options */
+#define PIOS_GPS_SETS_HOMELOCATION
+
 
 #endif /* PIOS_CONFIG_H */
 /**