I'm using the GPS Neo 6M for my hardware and connect it to the Arduino Uno and also the motor driver. As for now when I connect the whole hardware only the GPS is detected but my motor driver is not running. My robot needs to maintain drive in straight path by using the coordinate from gps. The coding doesn't have error, but my robot does not move. I'm quite new in coding. Please help me 
//include GPS Library
#include <TinyGPS++.h>
#include <TinyGPSPlus.h>
#include <SoftwareSerial.h>
//GPS RXTXPin and GPSBaud
static const int RXPin = 3, TXPin = 2;
static const uint32_t GPSBaud = 9600;
const int MOTORA_DIR_PIN = 4;
const int MOTORA_PWM_PIN = 5;
const int MOTORB_PWM_PIN = 6;
const int MOTORB_DIR_PIN = 7;
/* TOP VIEW, OF MOTOR
<MOTOR A> <MOTOR B>
|
|
<left tyre> | <rIGhT tyre>
*/
double latitude;
double longitude;
double targetLatitude = 3.5405;
const int CH_2_PIN = 8;
const int CH_3_PIN = 9;
const int CH_4_PIN = 10;
const int deadzone = 20;
int ch2, ch3, ch4;
int fwbw, lfrgt;
int32_t maxspeed;
int32_t truespeed;
float subspeed; // ch2 for forward and backward, ch3 for max speed,
//ch4 for right and left
// The TinyGPS++ object
TinyGPSPlus gps;
// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);
void setup() {
Serial.begin(9600);
pinMode(CH_4_PIN, INPUT); pinMode(CH_2_PIN, INPUT); pinMode(CH_3_PIN, INPUT);
pinMode(MOTORA_DIR_PIN, OUTPUT);
pinMode(MOTORA_PWM_PIN, OUTPUT);
pinMode(MOTORB_PWM_PIN, OUTPUT);
pinMode(MOTORB_DIR_PIN, OUTPUT);
ss.begin(GPSBaud); //GPS
}
void loop() {
//Read GPS data
while (ss.available() > 0){
gps.encode(ss.read());
if (gps.location.isUpdated()){
//Get GPS coordinate
latitude = gps.location.lat(), 6;
longitude = gps.location.lng(), 6;
Serial.print("Latitude= ");
Serial.print(gps.location.lat(), 6);
Serial.print(" Longitude= ");
Serial.println(gps.location.lng(), 6);
// read from higher channel pin first
ch4 = pulseIn(CH_4_PIN, HIGH, 40000); // 40000 is the delay to make it works
ch3 = pulseIn(CH_3_PIN, HIGH, 40000); // lower values will read 1 channel only
ch2 = pulseIn(CH_2_PIN, HIGH, 40000); //delayMicroseconds(1);
fwbw = pulseToPWM(ch2);
lfrgt = pulseToPWM(ch4);
if (ch3>2000){ch3=2000;}
if (ch3<970){ch3=970;}
maxspeed = map(ch3, 970, 2000, -1, 300);
maxspeed = constrain(maxspeed, 0, 255);
calcspeed();
if (fwbw > 0) {
digitalWrite(MOTORA_DIR_PIN, HIGH); digitalWrite(MOTORB_DIR_PIN, HIGH);
if ( latitude < targetLatitude - 0.0001) { //Turn left
analogWrite(MOTORB_PWM_PIN, 10); //truespeed
analogWrite(MOTORA_PWM_PIN, 30); //subspeed
// Serial.println("CHECK 1");
}
if (latitude > targetLatitude + 0.0001) { //Turn Right
analogWrite(MOTORB_PWM_PIN, 30); //subspeed
analogWrite(MOTORA_PWM_PIN, 10); //truespeed
// Serial.println("CHECK 2");
}
if (latitude == targetLatitude) { //Go Straight
analogWrite(MOTORB_PWM_PIN, 30); //truespeed
analogWrite(MOTORA_PWM_PIN, 30); //truespeed
//Serial.println("CHECK 3");
// delay (5000);
}
}
else if (fwbw < 0) {
// digitalWrite(MOTORA_DIR_PIN, LOW); digitalWrite(MOTORB_DIR_PIN, LOW);
analogWrite(MOTORA_PWM_PIN, 0);
analogWrite(MOTORB_PWM_PIN, 0);
}
}
/*
if (lfrgt < 0) {
analogWrite(MOTORB_PWM_PIN, 20); //truespeed
analogWrite(MOTORA_PWM_PIN, 10); //subspeed
//Serial.println("CHECK 4");
}
if (lfrgt > 0) {
analogWrite(MOTORB_PWM_PIN, 10); //subspeed
analogWrite(MOTORA_PWM_PIN, 20); //truespeed
//Serial.println("CHECK 5");
}
if (lfrgt == 0) {
analogWrite(MOTORB_PWM_PIN, 20); //truespeed
analogWrite(MOTORA_PWM_PIN, 20); //truespeed
//Serial.println("CHECK 6");
}
}
else if ((fwbw == 0)&&(lfrgt<-50)){
digitalWrite(MOTORA_DIR_PIN, LOW); digitalWrite(MOTORB_DIR_PIN, HIGH);
analogWrite(MOTORB_PWM_PIN, 20); //truespeed
analogWrite(MOTORA_PWM_PIN, 20); //truespeed
}
else if ((fwbw == 0)&&(lfrgt>50)){
digitalWrite(MOTORA_DIR_PIN, HIGH); digitalWrite(MOTORB_DIR_PIN, LOW);
analogWrite(MOTORA_PWM_PIN, 20); //truespeed
analogWrite(MOTORB_PWM_PIN, 20); //truespeed
}
else {
//Stop motor if no at 0,0 position
analogWrite(MOTORA_PWM_PIN, 0);
analogWrite(MOTORB_PWM_PIN, 0);
// Serial.println("CHECK 7");
}
*/
//printMapped(); //printCH();
}
}
void calcspeed() {
float xx=(lfrgt);
float yy=(fwbw);
float Rad=sqrt(xx*xx+yy*yy);
//truespeed = maxspeed*(abs(fwbw))/255;//;
truespeed = Rad*maxspeed/255;//;
subspeed = Rad*maxspeed/255*(abs(cos(abs(atan(xx / yy)))));
if (Rad>=255){
Rad=maxspeed;
truespeed = maxspeed;
subspeed = Rad*(abs(cos(abs(atan(xx / yy)))));
}
//return truespeed, subspeed;
}
void printCH() {
// Serial.print("CH2: ");
// Serial.print(ch2);
// Serial.print(", CH3: ");
// Serial.print(ch3);
// Serial.print(", CH4: ");
// Serial.println(ch4);
}
void printMapped() {
Serial.print("Forward Backward: ");
//Serial.print(ch2); Serial.print(", ");
Serial.print(fwbw);
Serial.print(", Left Right: ");// Serial.print(ch4);Serial.print(", ");
Serial.print(lfrgt);
Serial.print(", Max Speed: "); // Serial.print(ch3);Serial.print(", ");
Serial.print(maxspeed);
Serial.print(", truespeed: ");
Serial.print(truespeed);
Serial.print(", subspeed: ");
Serial.println(subspeed, 3);
}
int pulseToPWM(int pulse) {
int minreadval = 940; //940 val lower from the lowest valu read
int maxreadval = 2000; //2000 bithigher than highest value
// If we're receiving numbers, convert them to motor PWM
int pulses = pulse;
if ( pulses > minreadval ) {
pulse = map(pulse, minreadval, maxreadval, -300, 300);
pulse = constrain(pulse, -255, 255);
}
if (pulses < minreadval) {
pulse = -255;
}
// Anything in deadzone should stop the motor
if ( abs(pulse) <= deadzone ) {
pulse = 0;
}
return pulse;
}[quote="ahmedessam235, post:1, topic:373574, full:true"]
hey guys i'm building 2WD mobile robot using arduino mega and two motor of model 16G214E with built in encodrs MR2 i'm still planning the algorithm and i'm bit confused my goal is to give the robot distance between 1 to -20 meters and the robot will move that distance in straight line so to prevent deviation i will need PID control my algorithm is taking the input and mapping it into the encoder steps while the pid making sure the velocities of each wheel is equal
[/quote]
