Changes to accommodate blinking lights and loss of GPS commands. Tested with NMEA, uBlox, Sirf and MTK. Does not function correctly with rmack's changes to APM_Compass posted 10/17/2010 (I don't know why).

git-svn-id: https://arducopter.googlecode.com/svn/trunk@669 f9c3cf11-9bcb-44bc-f272-b75c42450872

libraries/AP_GPS/AP_GPS_MTK.cpp

@@ -126,10 +126,11 @@ restart:
 void 
 AP_GPS_MTK::_parse_gps(void)
 {
-	if (FIX_3D != _buffer.msg.fix_type) {
-		fix = false;
-	} else {
+	if (_buffer.msg.fix_type-1 >= 1){
 		fix = true;
+	} else {
+		fix = false;
+	}
 	latitude		= _swapl(&_buffer.msg.latitude)  * 10;
 	longitude		= _swapl(&_buffer.msg.longitude) * 10;
 	altitude		= _swapl(&_buffer.msg.altitude);
@@ -139,6 +140,7 @@ AP_GPS_MTK::_parse_gps(void)
 			
 	// XXX docs say this is UTC, but our clients expect msToW
 	time			= _swapl(&_buffer.msg.utc_time);
-	}
+	_setTime();
+	valid_read = true;
 	new_data = true;
 }

libraries/AP_GPS/AP_GPS_NMEA.cpp

@@ -112,18 +112,18 @@ AP_GPS_NMEA::parse_nmea_gps(void)
 	long aux_min;
 	char *parseptr;
 
-	
 	if (strncmp(buffer,"$GPGGA",6)==0){					// Check if sentence begins with $GPGGA
 		if (buffer[bufferidx-4]=='*'){					 // Check for the "*" character
 			NMEA_check = parseHex(buffer[bufferidx - 3]) * 16 + parseHex(buffer[bufferidx - 2]);		// Read the checksums characters
 			if (GPS_checksum == NMEA_check){			// Checksum validation
 				//Serial.println("buffer");
-				new_data = 1;	// New GPS Data
+				_setTime();
+				valid_read = true;
+				new_data = true;	// New GPS Data
 				parseptr = strchr(buffer, ',')+1;
 				//parseptr = strchr(parseptr, ',')+1;
 				time = parsenumber(parseptr, 2);					// GPS UTC time hhmmss.ss
 				parseptr = strchr(parseptr, ',')+1;
-				//
 				aux_deg = parsedecimal(parseptr, 2);			// degrees
 				aux_min = parsenumber(parseptr + 2, 4);		 // minutes (sexagesimal) => Convert to decimal
 				latitude = aux_deg * 10000000 + (aux_min * 50) / 3;	 // degrees + minutes / 0.6	( * 10000000) (0.6 = 3 / 5)
@@ -166,6 +166,9 @@ AP_GPS_NMEA::parse_nmea_gps(void)
 		if (buffer[bufferidx-4]=='*'){					 // Check for the "*" character
 			NMEA_check = parseHex(buffer[bufferidx - 3]) * 16 + parseHex(buffer[bufferidx - 2]);		// Read the checksums characters
 			if (GPS_checksum == NMEA_check){			// Checksum validation
+				_setTime();
+				valid_read = true;
+				new_data = true;	// New GPS Data
 				parseptr = strchr(buffer, ',')+1;
 				ground_course = parsenumber(parseptr, 2);			// Ground course in degrees * 100
 				parseptr = strchr(parseptr, ',')+1;

libraries/AP_GPS/AP_GPS_SIRF.cpp

@@ -175,6 +175,8 @@ AP_GPS_SIRF::_parse_gps(void)
 		if (ground_speed > 50)
 			ground_course	= _swapi(&_buffer.nav.ground_course);
 		num_sats		= _buffer.nav.satellites;
+		_setTime();
+		valid_read = 1;
 		break;
 	}
 	new_data = true;

libraries/AP_GPS/AP_GPS_UBLOX.cpp

@@ -184,5 +184,7 @@ AP_GPS_UBLOX::_parse_gps(void)
 		ground_course = _buffer.velned.heading_2d / 1000;	// Heading 2D deg * 100000 rescaled to deg * 100
 		break;
 	}
-	new_data = true;
+	_setTime();
+	valid_read = 1;
+	new_data = 1;
 }

libraries/AP_GPS/GPS.cpp

@@ -1,6 +1,7 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-
 
 #include "GPS.h"
+#include "WProgram.h"
 #include <stdio.h>
 
 void
@@ -13,6 +14,22 @@ GPS::update(void)
 {
 }
 
+void
+GPS::_setTime(void){
+	_lastTime = millis();
+}
+
+int
+GPS::status(void){
+	if (millis() - _lastTime >= 500){
+		return 0;
+	} else if (fix == 0) {
+		return 1;
+	} else {
+		return 2;
+	}
+}
+
 void
 GPS::_error(const char *fmt, ...)
 {

libraries/AP_GPS/GPS.h

@@ -52,6 +52,9 @@ public:
 	/// to false in order to avoid processing data they have
 	/// already seen.
 	bool	new_data;
+	bool	valid_read;
+
+	int	status(void);		///< 0 = Not Connected, 1 = Receiving Valid Messages but No Lock, 2 = Locked
 
 	bool	print_errors; 	///< if true, errors will be printed to stderr
 
@@ -66,6 +69,10 @@ protected:
 	///
 	long	_swapl(const void *bytes);
 
+	unsigned long _lastTime;	///< Timer for lost connection
+
+	void	_setTime(void);
+
 	/// perform an endian swap on an int
 	///
 	/// @param	bytes		pointer to a buffer containing bytes representing an
@@ -81,6 +88,7 @@ protected:
 	/// @param	fmt			printf-like format string
 	///
 	void	_error(const char *msg, ...);
+	
 };
 
 inline long