/* Instead of just merging input from a secondary device, which is
* part of the design of NMEA and which would make life easy, Trimble
* wraps messages in a proprietary message PTNLAG001. This handler
* just re-serializes the contents of that message and bounces
* it back to ArGPS for further parsing.
*/
void ArTrimbleGPS::handlePTNLAG001(ArNMEAParser::Message m)
{
ArNMEAParser::MessageVector *message = m.message;
if(message->size() < 2) return;
std::string text;
size_t len = 0;
// Undo split by commas, skip msg[0] which is "PTNLAG001"
for(ArNMEAParser::MessageVector::const_iterator i = message->begin() + 1; i != message->end(); ++i)
{
if(i != message->begin()) text += ",";
text += *i;
len += (*i).length() + 1;
}
#ifdef DEBUG_ARTRIMBLEGPS
printf("XXXXXXXXX Got PTNLAG001 contents from Trimble, %d bytes: %s\n", len, text.c_str());
#endif
// Reparse contents. Note, this will clobber NMEA parser state, including
// *message, so after calling this we can't do anything else with it. (So
// exit the function)
text += "\r\n";
len += 2;
myNMEAParser.parse(text.c_str(), len);
}
void ArNovatelGPS::handleNovatelGPGGA(ArNMEAParser::Message msg)
{
// call base handler
ArGPS::handleGPGGA(msg);
// Some of Novatel's values are different from the standard:
// (see
// http://na1.salesforce.com/_ui/selfservice/pkb/PublicKnowledgeSolution/d?orgId=00D300000000T86&id=501300000008RAN&retURL=%2Fsol%2Fpublic%2Fsolutionbrowser.jsp%3Fsearch%3DGPGGA%26cid%3D000000000000000%26orgId%3D00D300000000T86%26t%3D4&ps=1 or search Novatel's Knowlege Base for "GPGGA")
ArNMEAParser::MessageVector *message = msg.message;
if(message->size() < 7) return;
switch((*message)[6].c_str()[0])
{
case '2':
myData.fixType = OmnistarConverging;
break;
case '5':
myData.fixType = OmnistarConverged;
break;
case '9':
myData.fixType = DGPSFix;
break;
}
}
int TestArGPS::tests() {
puts("");
double degmin = 4248.32544;
double deg = gpsDegminToDegrees(degmin);
printf("Degrees/minutes combination %f converts to decimal degrees %f.\nChecking against correct value 42.805424...\n", degmin, deg);
assert(floatsCloseEnough(deg, 42.805424));
puts("OK");
puts("");
degmin = -4248.32544;
deg = gpsDegminToDegrees(degmin);
printf("Degrees/minutes combination %f converts to decimal degrees %f.\nChecking against correct value -42.805424... \n", degmin, deg);
assert(floatsCloseEnough(deg, -42.805424));
puts("OK");
puts("");
ArNMEAParser::MessageVector msgParts;
msgParts.push_back("GPRMC");
msgParts.push_back("1.1"); // timestamp
msgParts.push_back("A"); // warning flag
msgParts.push_back("4248.32544"); // latitude
msgParts.push_back("N"); // lat n/s
msgParts.push_back("7234.293016"); // longitude
msgParts.push_back("E"); // lon e/w
msgParts.push_back("0"); // speed
ArNMEAParser::Message msg;
msg.message = &msgParts;
handleGPRMC(msg);
printf("Extracted and converted data from preconstructed GPRMC message with north latitude, east latitude: lat=%f, lon=%f, time.sec=%lu, time.msec=%lu, speed=%f.\nChecking against correct values lat=42.805424 lon=72.571550, time.sec=1, time.mseg=100, speed=0.0...\n", myData.latitude, myData.longitude, myData.GPSPositionTimestamp.getSec(), myData.GPSPositionTimestamp.getMSec(), myData.speed);
assert(myData.havePosition);
assert(floatsCloseEnough(myData.latitude, 42.805424));
assert(floatsCloseEnough(myData.longitude, 72.571550));
assert(myData.GPSPositionTimestamp.getSec() == 1);
assert(myData.GPSPositionTimestamp.getMSec() == 100);
assert(floatsCloseEnough(myData.speed, 0.0));
puts("OK");
puts("");
msgParts[4] = "S";
msgParts[6] = "W";
handleGPRMC(msg);
printf("Extracted and converted data from preconstructed GPRMC message with south latitude, west longitude: lat=%f, lon=%f, time.sec=%lu, time.msec=%ld, speed=%f.\nChecking against correct values lat=-42.805424 lon=-72.57155...\n", myData.latitude, myData.longitude, myData.GPSPositionTimestamp.getSec(), myData.GPSPositionTimestamp.getMSec(), myData.speed);
assert(myData.havePosition);
assert(floatsCloseEnough(myData.latitude, -42.805424));
assert(floatsCloseEnough(myData.longitude, -72.57155));
puts("OK");
puts("");
msgParts[6] = "xxx";
msgParts[1] = "2";
handleGPRMC(msg);
printf("Extracted and converted data from preconstructed GPRMC message with south latitude, invalid (\"xxx\") longitude, message should have been ignored (timestamp should still show 1/100, not 2.): lat=%f, lon=%f, time.sec=%lu, time.msec=%ld, speed=%f.\nChecking against correct values lat=-42.805424 lon=-72.57155, time.sec!=2...\n", myData.latitude, myData.longitude, myData.GPSPositionTimestamp.getSec(), myData.GPSPositionTimestamp.getMSec(), myData.speed);
assert(floatsCloseEnough(myData.latitude, -42.805424));
assert(floatsCloseEnough(myData.longitude, -72.57155));
assert(myData.GPSPositionTimestamp.getSec() != 2);
puts("OK");
puts("");
puts("Now testing messages with invalid NMEA format (checksums should be seen as wrong, or messages ignored).");
char *malformedMessage1 = "$GPRMC,11\r\n99,22$33,44*5*6\n" ; // broken halfway through
char *malformedMessage2 = "xxx\r\nxxxx\r\n"; // not an nmea message
char *malformedMessage3 = "$*01\r\n"; // missing key contents. maybe acepted by ignored?
char *malformedMessage4 = "$GPRMC,11,22,33\r\n"; // missing checksum
char *malformedMessage5 = "$GPRMC,11,22$GPRMC,99,$GPR33MC88,77*01\r**0\n203\r\n"; // overlapping messages
puts("\nMessage 1 of 5...");
myNMEAParser.parse(malformedMessage1, strlen(malformedMessage1));
myNMEAParser.parse("\r\n\r\n", 4);
puts("\nMessage 2 of 5...");
myNMEAParser.parse(malformedMessage2, strlen(malformedMessage2));
myNMEAParser.parse("\r\n\r\n", 4);
puts("\nMessage 3 of 5...");
myNMEAParser.parse(malformedMessage3, strlen(malformedMessage3));
myNMEAParser.parse("\r\n\r\n", 4);
puts("\nMessage 4 of 5...");
myNMEAParser.parse(malformedMessage4, strlen(malformedMessage4));
myNMEAParser.parse("\r\n\r\n", 4);
puts("\nMessage 5 of 5...");
myNMEAParser.parse(malformedMessage5, strlen(malformedMessage5));
myNMEAParser.parse("\r\n\r\n", 4);
puts("");
char *text = "HCHDM,123.4,M";
char chk = 0;
for(unsigned int i = 0; i < strlen(text); ++i)
{
chk ^= text[i];
}
printf("Checking checksum algorithm: Checksum for example message contents \"%s\" is 0x%X (%d). (ought to be 0x2D). Checking...\n", text, chk&0xFF, chk&0xFF);
assert(chk == 0x2D);
puts("OK");
puts("");
puts("Testing a message with a correct checksum. Should be no checksum warnings.");
char *messageWithGoodChecksum = "$HCHDM,123.4,M*2D\r\n";
myNMEAParser.parse(messageWithGoodChecksum, strlen(messageWithGoodChecksum));
puts("");
puts("Testing messages with incorrect checksums. Should see checksum warnings.");
char *messageWithBadChecksum = "$HCHDM,123.4,M*23\r\n";
myNMEAParser.parse(messageWithBadChecksum, strlen(messageWithBadChecksum));
myNMEAParser.parse("\r\n\r\n", 4);
messageWithBadChecksum = "$HCHDM,123.4,z*2D\r\n";
myNMEAParser.parse(messageWithBadChecksum, strlen(messageWithBadChecksum));
myNMEAParser.parse("\r\n\r\n", 4);
puts("");
puts("Done.");
return 0;
}