From 1bfcdaa2cbc8465b47d3eb3bbe3b20443608d1d6 Mon Sep 17 00:00:00 2001
From: "DrZiplok@gmail.com"
 <DrZiplok@gmail.com@f9c3cf11-9bcb-44bc-f272-b75c42450872>
Date: Mon, 10 Jan 2011 01:50:42 +0000
Subject: [PATCH] Add a delay after sending the GPS mode switch strings in an
 attempt to give any NMEA data time to drain before we attempt to sniff again.

Otherwise, we can end up settling on NMEA as a mode just after switching a SiRF GPS to binary mode.

git-svn-id: https://arducopter.googlecode.com/svn/trunk@1467 f9c3cf11-9bcb-44bc-f272-b75c42450872
---
 libraries/AP_GPS/AP_GPS_Auto.cpp | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/libraries/AP_GPS/AP_GPS_Auto.cpp b/libraries/AP_GPS/AP_GPS_Auto.cpp
index 4d5a9b3c4e..e845b6ceb8 100644
--- a/libraries/AP_GPS/AP_GPS_Auto.cpp
+++ b/libraries/AP_GPS/AP_GPS_Auto.cpp
@@ -8,7 +8,7 @@
 
 static unsigned int	baudrates[] = {38400U, 57600U, 9600U, 4800U};
 
-AP_GPS_Auto::AP_GPS_Auto(FastSerial *port, GPS **gps)  : 
+AP_GPS_Auto::AP_GPS_Auto(FastSerial *port, GPS **gps)  :
 	GPS(port),
 	_FSport(port),	// do we need this, or can we cast _port up?
 	_gps(gps)
@@ -42,7 +42,7 @@ AP_GPS_Auto::read(void)
 			if (NULL != (gps = _detect())) {
 				// make the detected GPS the default
 				*_gps = gps;
-				
+
 				// configure the detected GPS and run one update
 				gps->print_errors = true;	// XXX
 				gps->init();
@@ -68,7 +68,7 @@ AP_GPS_Auto::_detect(void)
 	GPS		*gps;
 
 	//
-	// Loop attempting to detect a recognised GPS
+	// Loop attempting to detect a recognized GPS
 	//
 	gps = NULL;
 	for (tries = 0; tries < 2; tries++) {
@@ -88,7 +88,7 @@ AP_GPS_Auto::_detect(void)
 				_port->read();
 			}
 		} while ((millis() - then) < 50);
-			
+
 		//
 		// Collect four characters to fingerprint a device
 		//
@@ -104,11 +104,11 @@ AP_GPS_Auto::_detect(void)
 			   fingerprint[3]);
 
 		//
-		// u-blox or MTK in DIYD binary mode (whose smart idea was
+		// ublox or MTK in DIYD binary mode (whose smart idea was
 		// it to make the MTK look sort-of like it was talking UBX?)
 		//
 		if ((0xb5 == fingerprint[0]) &&
-			(0x62 == fingerprint[1]) && 
+			(0x62 == fingerprint[1]) &&
 			(0x01 == fingerprint[2])) {
 
 			// message 5 is MTK pretending to talk UBX
@@ -118,17 +118,17 @@ AP_GPS_Auto::_detect(void)
 				break;
 			}
 
-			// any other message is u-blox
-			Serial.printf("detected u-blox in binary mode\n");
+			// any other message is ublox
+			Serial.printf("detected ublox in binary mode\n");
 			gps = new AP_GPS_UBLOX(_port);
 			break;
-		} 
+		}
 
 		//
 		// MTK v1.6
 		//
 		if ((0xd0 == fingerprint[0]) &&
-			(0xdd == fingerprint[1]) && 
+			(0xdd == fingerprint[1]) &&
 			(0x20 == fingerprint[2])) {
 			Serial.printf("detected MTK v1.6\n");
 			gps = new AP_GPS_MTK16(_port);
@@ -154,6 +154,9 @@ AP_GPS_Auto::_detect(void)
 			_port->println(MTK_SET_BINARY);
 			_port->println(UBLOX_SET_BINARY);
 			_port->println(SIRF_SET_BINARY);
+
+			// give the GPS time to react to the settings
+			delay(100);
 			continue;
 		}