GPS Programming Help

Projects General Guidance
1

Hello Everyone,

I am new to Arduino world and this forum. I am working on a project where I want to have a self-driving car go to a GPS-programmed destination using given coordinates (latitude and longitude). The car should go the destination and come back to starting point (will have to save initial position = starting point).

The project is long, but i chopped the code to only include the GPS part and the functions to start and stop the car.

I don't know how to enter my destination coordinates for the car to follow. Please see the attached code, it has a lot of description to say what the end product will be, but i removed most other functions that are not needed.

I am using Arduino UNO and NEO-6M GPS module

Please help me!

Thanks!
DJ

===============================================================
Code:

/* By Kaswa
*

  • The goal of this project is to similate a self-driving car.
  • Procedure:
    1. A set of coordinates (lat and long) will be saved to a variable for the GPS module to tell the car where to go.
    1. GPS module will communicate with sattelite to get current coordinates and save those to a different variable.
  • These coordinates will be used for the car to come back to initial position from where it will be sent.
    1. Once ready, Green LED will blind rapidly to indicate that the car is ready to go.
    1. The rear motor of the car will be instructed to begin the forward motion to take the car to the destination entered
  • at step 1, and the car should avoid any obstable on its way by using the Ping sensors mounted to the front, and sides.
    1. Once at destination, car will stop, Green and Red will blind for 4 seconds, then car will used coordinates saved for initial
  • position to be loaded to the GPS and return to initial starting point.
  • */

/*

  • HC-SR04 Ping distance sensor:
  • VCC to arduino 5v
  • GND to arduino GND
  • Trig to Arduino: Right - pin13, ctr - pin11, left - pin9
  • Echo to Arduino: Right - pin 12, ctr - pin10, left - pin8
    */

// GPS Library and Software Serial
#include "TinyGPS++.h"
#include "SoftwareSerial.h"

// Pin assignments
#define trigLeft 9 // Trigger Left Sensor
#define trigCtr 11 // Trigger Center Sensor
#define trigRight 13 // Trigger Right Sensor
#define echoLeft 8 // Echo Left Sensor
#define echoCtr 10 // Echo Center Sensor
#define echoRight 12 // Echo Right Sensor
#define front1 A0 // Motor 1, out 1
#define front2 A1 // Motor 1, out 2
#define rear1 A2 // Motor 2, out 3
#define rear2 A3 // Motor 2, out 4
#define enA 6 // Enable sig for mot1 PWM, black wire
#define enB 5 // Enable sig for mot2 PWM, brown wire
#define gpsTX 4 // Transmit signal PIN, purple wire GPS --> Yellow wire Arduino
#define gpsRX 3 // Receive signal PIN, blue wire

// Setting up Serial Port and GPS Module
SoftwareSerial serial_connection(gpsTX, gpsRX);
TinyGPSPlus gps; // Will convert NMEA Data to readable format

// Values initialization
int initSP = 200; // Rear Motor Initial spin speed
int maxSP = 150; // Rear Motor Max spin speed
int minRange = 20; // Minimum Ping Senor range needed
long duration; // Duration used to calculate distance for Ping Sensor
long distance; // Distance for center Ping Sensor
long distanceLeft; // Distance for left side Sensor
long distanceRight; // Distance for right side sensor
float xInit; // Car GPS Initial Latitude
float yInit; // Car GPS Initial Longitude
float xNew; // Car GPS Destination Latitude ** SET THIS TO A DEFINED VALUE i.e xNew = 39.797767 **
float yNew; // Car GPS Destination Longitude ** SET THIS TO A DEFINED VALUE i.e yNew = -85.973077 **
float flat; // GPS latitude variable
float flon; // GPS longitude variable

// Code Begins
void setup()
{
Serial.begin (9600);
serial_connection.begin(9600); // This opens up communications to the GPS module

// Ping Sensor Pins
pinMode(trigLeft, OUTPUT);
pinMode(echoLeft, INPUT);
pinMode(trigCtr, OUTPUT);
pinMode(echoCtr, INPUT);
pinMode(trigRight, OUTPUT);
pinMode(echoRight, INPUT);

// Motor Pins
pinMode(front1, OUTPUT);
pinMode(front2, OUTPUT);
pinMode(rear1, OUTPUT);
pinMode(rear2, OUTPUT);
pinMode(enA, OUTPUT);
pinMode(enB, OUTPUT);

}

void loop() // Main Program Loop
{
GPSloop();

xInit = flat;
yInit = flon;

/*How do you load xNew and yNew to the GPS so that we can then call the rear motor fonction to send the car to that

  • location?
  • */

rearMotfwd();
brake();

}

//GPS Code taken from Arduino_GPS/Arduino_GPS.ino at master · LessonStudio/Arduino_GPS · GitHub
void GPSloop()
{
while(serial_connection.available()) // While there are characters to come from the GPS
{
gps.encode(serial_connection.read()); // This feeds the serial NMEA data into the library one char at a time
}
if(gps.location.isUpdated())//This will pretty much be fired all the time anyway but will at least reduce it to only after a package of NMEA data comes in
{
//Get the latest info from the gps object which it derived from the data sent by the GPS unit
Serial.println("Latitude:");
Serial.println(gps.location.lat(), 6);
Serial.println("Longitude:");
Serial.println(gps.location.lng(), 6);

}
}

void rearMotfwd() // Rear Motor Forward Motion Function
{
// Forward Rear Motor
digitalWrite(rear1, HIGH); // These two lines set the direction of the motor
digitalWrite(rear2, LOW); // to forward

analogWrite(enB, maxSP); // Gives the speed for the motor to start moving

//delay(300);

}

// pingSens(); // This function checks if there's any obstacle in front of car

}

void brake() // Function to brake the car/ stop its motion
{
analogWrite(enB, 0); // Removes the speed from the motor
digitalWrite(rear1, LOW);
digitalWrite(rear2, LOW);

digitalWrite(rear1, LOW); // These two lines revert the direction
digitalWrite(rear2, HIGH); // of the motor
analogWrite(enB, maxSP); // Apply the speed
delay(300);

analogWrite(enB, 0); // Removes the speed from the motor
digitalWrite(rear1, LOW);
digitalWrite(rear2, LOW);

}

GPSPortion.ino (5.59 KB)