Расшифруйте код GPS NMEA с помощью Arduino

Я искал в Интернете, и лучший ответ будет использовать библиотеку «TinyGPS ++» для Arduino. Почти все связанные с GPS коды уже включены в библиотеку.

Данные NMEA представлены в формате GPS (ddmm.ssss), Google хочет использовать их в десятичном стиле (dd.mmssss), в нижней части кода для этого шага есть функция покрытия.

Я написал это, потому что мне не нравятся большие, сложные библиотеки, чтобы делать простые мелочи, особенно когда я пытаюсь понять, как это работает.
Это анализирует предложение GLL, но вы можете изменить искомое предложение и переставить разделы, если это необходимо.

String ReadString;

void setup() {
Serial.begin(9600);  //Arduino serial monitor thru USB cable
Serial1.begin(9600); // Serial1 port connected to GPS
}

void loop() {
ReadString=Serial1.readStringUntil(13);   //NMEA data ends with 'return' character, which is ascii(13)
ReadString.trim();                      // they say NMEA data starts with "$", but the Arduino doesn't think so.
// Serial.println(ReadString);         //All the raw sentences will be sent to monitor, if you want them, maybe to see the labels and data order.

//Start Parsing by finding data, put it in a string of character array, then removing it, leaving the rest of thes sentence for the next 'find'
if (ReadString.startsWith("$GPGLL")) {   //I picked this sentence, you can pick any of the other labels and rearrange/add sections as needed.
Serial.println(ReadString);     // display raw GLL data in Serial Monitor
// mine looks like this: "$GPGLL,4053.16598,N,10458.93997,E,224431.00,A,D*7D"
//This section gets repeated for each delimeted bit of data by looking for the commas
//Find Lattitude is first in GLL sentence, other senetences have data in different order
int Pos=ReadString.indexOf(',');   //look for comma delimetrer
ReadString.remove(0, Pos+1); // Remove Pos+1 characters starting at index=0, this one strips off "$GPGLL" in my sentence
Pos=ReadString.indexOf(','); //looks for next comma delimetrer, which is now the first comma because I removed the first segment
char Lat[Pos];            //declare character array Lat with a size of the dbit of data
for (int i=0; i <= Pos-1; i++){    // load charcters into array
Lat[i]=ReadString.charAt(i);
}
Serial.print(Lat);          // display raw latitude data in Serial Monitor, I'll use Lat again in a few lines for converting
//repeating with a different char array variable
//Get Lattitude North or South
ReadString.remove(0, Pos+1);
Pos=ReadString.indexOf(',');
char LatSide[Pos];           //declare different variable name
for (int i=0; i <= Pos-1; i++){
LatSide[i]=ReadString.charAt(i);  //fill the array
Serial.println(LatSide[i]);       //display N or S
}

//convert the variable array Lat to degrees Google can use
float LatAsFloat = atof (Lat);            //atof converts the char array to a float type
float LatInDeg;
if(LatSide[0]==char(78)) {        //char(69) is decimal for the letter "N" in ascii chart
LatInDeg= ConvertData(LatAsFloat);   //call the conversion funcion (see below)
}
if(LatSide[0]==char(83)) {        //char(69) is decimal for the letter "S" in ascii chart
LatInDeg= -( ConvertData(LatAsFloat));   //call the conversion funcion (see below)
}
Serial.println(LatInDeg,15); //display value Google can use in Serial Monitor, set decimal point value high
//repeating with a different char array variable
//Get Longitude
ReadString.remove(0, Pos+1);
Pos=ReadString.indexOf(',');
char Longit[Pos];             //declare different variable name
for (int i=0; i <= Pos-1; i++){
Longit[i]=ReadString.charAt(i);      //fill the array
}
Serial.print(Longit);      //display raw longitude data in Serial Monitor
//repeating with a different char array variable
//Get Longitude East or West
ReadString.remove(0, Pos+1);
Pos=ReadString.indexOf(',');
char LongitSide[Pos];         //declare different variable name
for (int i=0; i <= Pos-1; i++){
LongitSide[i]=ReadString.charAt(i);      //fill the array
Serial.println(LongitSide[i]);        //display raw longitude data in Serial Monitor
}
//convert to degrees Google can use
float LongitAsFloat = atof (Longit);    //atof converts the char array to a float type
float LongInDeg;
if(LongitSide[0]==char(69)) {        //char(69) is decimal for the letter "E" in ascii chart
LongInDeg=ConvertData(LongitAsFloat);   //call the conversion funcion (see below
}
if(LongitSide[0]==char(87)) {         //char(87) is decimal for the letter "W" in ascii chart
LongInDeg=-(ConvertData(LongitAsFloat)); //call the conversion funcion (see below
}
Serial.println(LongInDeg,15);  //display value Google can use in Serial Monitor, set decimal point value high
//repeating with a different char array variable
//Get TimeStamp - GMT
ReadString.remove(0, Pos+1);
Pos=ReadString.indexOf(',');
char TimeStamp[Pos];          //declare different variable name
for (int i=0; i <= Pos-1; i++){
TimeStamp[i]=ReadString.charAt(i);         //fill the array
}
Serial.print(TimeStamp);   //display raw longitude data in Serial Monitor, GMT
Serial.println("");
}
}

//Conversion function
float ConvertData(float RawDegrees)
{
float RawAsFloat = RawDegrees;
int firstdigits = ((int)RawAsFloat)/100; // Get the first digits by turning f into an integer, then doing an integer divide by 100;
float nexttwodigits = RawAsFloat - (float)(firstdigits*100);
float Converted = (float)(firstdigits + nexttwodigits/60.0);
return Converted;
}

Попробуйте это, которое может помочь вам

#include <SoftwareSerial.h>
#include <TinyGPS.h>

TinyGPS gps;
SoftwareSerial ss(3,4);static void smartdelay(unsigned long ms);
static void print_float(float val, float invalid, int len, int prec);
static void print_int(unsigned long val, unsigned long invalid, int len);
static void print_date(TinyGPS &gps);
static void print_str(const char *str, int len);

void setup()
{
Serial.begin(9600);
ss.begin(9600);
}

void loop()
{
float flat, flon;

unsigned short sentences = 0, failed = 0;

gps.f_get_position(&flat, &flon);
Serial.print("LATITUDE: ");
print_float(flat, TinyGPS::GPS_INVALID_F_ANGLE, 10, 6);
Serial.println(" ");
Serial.print("LONGITUDE: ");
print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 11, 6);
Serial.println(" ");

Serial.print("altitude: ");
print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 7, 2);
Serial.println(" ");
Serial.print("COURSE:");
print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2);
Serial.println("");

Serial.print("DIRECTION: ");
int d;
print_str(gps.f_course() == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(gps.f_course()), 6);
d=gps.f_course();
Serial.println();
Serial.println();
smartdelay(1000);

}

static void smartdelay(unsigned long ms)
{
unsigned long start = millis();
do
{
while (ss.available())
gps.encode(ss.read());
} while (millis() - start < ms);
}

static void print_float(float val, float invalid, int len, int prec)
{
if (val == invalid)
{
while (len-- > 1)
Serial.print('*');
Serial.print(' ');
}
else
{
Serial.print(val, prec);
int vi = abs((int)val);
int flen = prec + (val < 0.0 ? 2 : 1); // . and -
flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
for (int i=flen; i<len; ++i)
Serial.print(' ');
}
smartdelay(0);
}

static void print_int(unsigned long val, unsigned long invalid, int len)
{
char sz[32];
if (val == invalid)
strcpy(sz, "*******");
else
sprintf(sz, "%ld", val);
sz[len] = 0;
for (int i=strlen(sz); i<len; ++i)
sz[i] = ' ';
if (len > 0)
sz[len-1] = ' ';
Serial.print(sz);
smartdelay(0);
}
static void print_str(const char *str, int len)
{
int slen = strlen(str);
for (int i=0; i<len; ++i)
Serial.print(i<slen ? str[i] : ' ');
smartdelay(0);
}