First commit for GPS code, Using HardwareSerial for Serial comms.

_rodGPS_SimpleDistance() function to calculate distance between two points.
_rodGPS_MakeReading() to make a reading from GPS IC.
_rodGPS_PrintGPRMC() to print data
simple_GPRMC struct defined to store data given by IC. Use std::atof to convert the strings to float values

Signed-off-by: Rodrigo Amaral <roaa1g19@soton.ac.uk>

rodGPS/.gitignore

+.pio
+.vscode/.browse.c_cpp.db*
+.vscode/c_cpp_properties.json
+.vscode/launch.json
+.vscode/ipch

rodGPS/.vscode/extensions.json

+{
+    // See http://go.microsoft.com/fwlink/?LinkId=827846
+    // for the documentation about the extensions.json format
+    "recommendations": [
+        "platformio.platformio-ide"
+    ]
+}

rodGPS/.vscode/settings.json

+{
+    "files.associations": {
+        "array": "cpp",
+        "*.tcc": "cpp",
+        "cctype": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "cstdarg": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "cwchar": "cpp",
+        "cwctype": "cpp",
+        "deque": "cpp",
+        "unordered_map": "cpp",
+        "unordered_set": "cpp",
+        "vector": "cpp",
+        "exception": "cpp",
+        "algorithm": "cpp",
+        "functional": "cpp",
+        "system_error": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "fstream": "cpp",
+        "initializer_list": "cpp",
+        "iomanip": "cpp",
+        "iosfwd": "cpp",
+        "istream": "cpp",
+        "limits": "cpp",
+        "memory": "cpp",
+        "new": "cpp",
+        "ostream": "cpp",
+        "numeric": "cpp",
+        "sstream": "cpp",
+        "stdexcept": "cpp",
+        "streambuf": "cpp",
+        "cinttypes": "cpp",
+        "utility": "cpp",
+        "typeinfo": "cpp"
+    }
+}
\ No newline at end of file

rodGPS/include/README

+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

rodGPS/lib/README

+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

rodGPS/platformio.ini

+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:esp32dev]
+platform = espressif32
+board = esp32dev
+framework = arduino
+monitor_speed = 9600
+upload_port = com9

rodGPS/src/main.cpp

+#include "rodGPS.hpp"
+
+static simple_GPRMC gprmc_buff;
+static simple_GPRMC test;
+
+void setup() 
+{
+  Serial2.begin(9600);
+  Serial.begin(9600);
+  while (!Serial){;} /*Used for native USB support */
+  Serial.println("\n-------------------------\n");
+}
+
+void loop() 
+{
+  _rodGPS_MakeReading(&gprmc_buff, &test);
+  Serial.print(std::atof("32.575"));
+  Serial.write("\n\n");
+}

rodGPS/src/rodGPS.cpp

+#include "rodGPS.hpp"
+
+void _rodGPS_PrintGPRMC(simple_GPRMC* gprmc_data)
+{
+  Serial.write("\nValidity: ");
+  Serial.write(gprmc_data->VALID);
+
+  Serial.write("\nTime: ");
+  Serial.write(gprmc_data->TIME[0]);
+  Serial.write(gprmc_data->TIME[1]);
+  Serial.write(':');
+  Serial.write(gprmc_data->TIME[2]);
+  Serial.write(gprmc_data->TIME[3]);
+  Serial.write(':');
+  Serial.write(gprmc_data->TIME[4]);
+  Serial.write(gprmc_data->TIME[5]);
+
+  Serial.write("  Date: ");
+  Serial.write(gprmc_data->DATE[0]);
+  Serial.write(gprmc_data->DATE[1]);
+  Serial.write('/');
+  Serial.write(gprmc_data->DATE[2]);
+  Serial.write(gprmc_data->DATE[3]);
+  Serial.write('/');
+  Serial.write(gprmc_data->DATE[4]);
+  Serial.write(gprmc_data->DATE[5]);
+
+  Serial.write("\nLatitude: ");
+  Serial.write((uint8_t*)&(gprmc_data->LATI),10);
+  Serial.write(gprmc_data->LATI_DIR);
+  Serial.write("  Longitude: ");
+  Serial.write((uint8_t*)&(gprmc_data->LONG),11);
+  Serial.write(gprmc_data->LONG_DIR);
+
+  Serial.write("\n\n");
+}
+
+double _rodGPS_SimpleDistance(simple_GPRMC* coord_1, simple_GPRMC* coord_2)
+{
+  double dx = 111.3 * cos((std::atof(coord_1->LATI) + std::atof(coord_2->LATI) / 2 * 0.01745)*(PI / 180)) * (std::atof(coord_1->LONG) - std::atof(coord_2->LONG));
+  double dy = 111.3 * ((std::atof(coord_1->LATI)) - (std::atof(coord_2->LATI)));
+  return sqrt( dx*dx + dy*dy );
+}
+
+static char char_buff[5];
+byte _rodGPS_MakeReading(simple_GPRMC* gprmc1, simple_GPRMC* gprmc2)
+{
+  while(Serial2.available() == 0) {;}
+
+  while(Serial2.available() > 0)
+  {
+    int c = Serial2.read();
+    while(c != '$') {c = Serial2.read();}
+    
+    for(char i = 0; i < 5; i++)
+      char_buff[i] = Serial2.read();
+
+    if(char_buff[2] == 'R' | char_buff[3] == 'M' | char_buff[4] == 'R') /* Check it's GPRMC data, there are several coming trough */
+    {
+      byte struct_count = 0;
+
+      while ((c = Serial2.read()) != '\n')
+      {
+        if(c == ',') /* The Data structure of GPRMC is divided in commas */
+          struct_count++;
+
+        if(struct_count == 1) /* Time HH MM SS MSMS */
+        {
+          for(byte ii = 0; ii < 9; ii++)
+          {
+            gprmc1->TIME[ii] = Serial2.read();
+          }
+        }
+        else if(struct_count == 2) /* Validity, A-ok V-void */
+        {
+            gprmc1->VALID = Serial2.read();
+        }
+        else if(struct_count == 3) /* Latitude 5 decimal places */
+        {
+          for(byte ii = 0; ii < 10; ii++)
+            gprmc1->LATI[ii] = Serial2.read();
+        }
+        else if(struct_count == 4) /* Latitude direction N / S */
+        {
+          gprmc1->LATI_DIR = Serial2.read();
+        }
+        else if(struct_count == 5) /* Longitude 5 decimal cases */
+        {
+          for(byte ii = 0; ii < 11; ii++)
+            gprmc1->LONG[ii] = Serial2.read();
+        }
+        else if(struct_count == 6) /* Longitutde direction E / W */
+        {
+          gprmc1->LONG_DIR = Serial2.read();
+        }
+        else if(struct_count == 9) /* Date DD MM YY */
+        {
+          for(byte ii = 0; ii < 6; ii++)
+            gprmc1->DATE[ii] = Serial2.read();
+        }
+      }
+
+      _rodGPS_PrintGPRMC(gprmc1);
+      Serial.write("Distance: ");
+      Serial.println(String((_rodGPS_SimpleDistance(gprmc1,gprmc2)),2));
+      Serial.write("\n\n");
+
+      for(byte i = 0; i < 10; i++)
+        gprmc2->LATI[i] = gprmc1->LATI[i];
+      for(byte i = 0; i < 11; i++)
+        gprmc2->LONG[i] = gprmc1->LONG[i];
+    }
+  }
+  return 0;
+}
\ No newline at end of file

rodGPS/src/rodGPS.hpp

+#include <Arduino.h>
+#include <HardwareSerial.h>
+#include <string.h>
+
+#ifndef RODGPS_HPP
+#define RODGPS_HPP
+
+typedef struct simple_GPRMC
+{
+  char TIME[9];
+  char DATE[6];
+  char VALID;
+
+  char LATI[10];
+  char LATI_DIR;
+  char LONG[11];
+  char LONG_DIR;
+};
+
+void _rodGPS_PrintGPRMC(simple_GPRMC* gprmc_data);
+double _rodGPS_SimpleDistance(simple_GPRMC* coord_1, simple_GPRMC* coord_2);
+byte _rodGPS_MakeReading(simple_GPRMC* gprmc1, simple_GPRMC* gprmc2);
+
+#endif /* RODGPS_HPP */
\ No newline at end of file

rodGPS/test/README

+
+This directory is intended for PlatformIO Unit Testing and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PlatformIO Unit Testing:
+- https://docs.platformio.org/page/plus/unit-testing.html