final

/*************************************************************************************
*  Robot Control with Android App and NodeMCU
*
*  Differential Robot using H-Bridget L293D
*   
*  Voice activation and response
*
*  Developed by Marcelo Rovai on 31March17
*  Visit my blog: https://MJRoBot.org 
*   
************************************************************************************/
#include <ESP8266WiFi.h>
WiFiClient client;
WiFiServer server(80);
const char* ssid = "hello nodemcu";
const char* password = "nodemcu4";
String  command =""; // Command received from Android device


// Set Motor Control Pins
int rightMotor2 = 12;    // D7 - right Motor -
int rightMotor1 = 13;    // D8 - right Motor +
int leftMotor2 = 0;    // D3 - left Motor - 
int leftMotor1 = 2;    // D4 - left Motor +

int sensorValue;
float voltage;
int serialCount = 0;


void setup()
{
  Serial.begin(115200);

  pinMode(leftMotor1, OUTPUT); 
  pinMode(leftMotor2, OUTPUT);  
  pinMode(rightMotor1, OUTPUT);  
  pinMode(rightMotor2, OUTPUT);  

  digitalWrite(leftMotor1,LOW);
  digitalWrite(leftMotor2,LOW);
  digitalWrite(rightMotor1,LOW);
  digitalWrite(rightMotor2,LOW);

  pinMode(14, OUTPUT);
      
  connectWiFi();
  server.begin();
}

void loop()
{
  
  
 if(serialCount == 10000) {
    sensorValue = analogRead(A0);
    voltage = sensorValue * (5.0/1023.0);
    Serial.println(voltage);
    serialCount = 0;
  }
  else {
    serialCount ++;
  }

    digitalWrite(14, HIGH);
    
    if(voltage < 1.5) {
      
      stopMotor();
      return;
    }
    
    client = server.available();
    if (!client) return;
    command = checkClient();

    if(voltage > 1.5) {
      
        if (command == "forward" || command == "go%20forward"){
          
          forwardMotor();
         }
         else if (command == "reverse" || command == "backward" || command == "go%20back"){
          
          reverseMotor();
         }
         else if (command == "left" || command == "turn%20left"){
          
          leftMotor();    
          }
          else if (command == "right" || command == "turn%20right") {
          
          rightMotor();     
          }
          else if (command == "stop")     {
          
          stopMotor();     
          }
     
    sendBackEcho(command); // send command echo back to android device
    command = ""; 
    
    }
     
      
}


/* command motor forward */
void forwardMotor(void)   
{
    analogWrite(leftMotor1, 750);
    analogWrite(rightMotor1, 600);
    analogWrite(leftMotor2, 0);
    analogWrite(rightMotor2, 0);
          
  digitalWrite(leftMotor1,HIGH);
  digitalWrite(leftMotor2,LOW);
  digitalWrite(rightMotor1,HIGH);
  digitalWrite(rightMotor2,LOW);
}

/* command motor backward */
void reverseMotor(void)   
{
  analogWrite(leftMotor1, 0);
          analogWrite(rightMotor1, 0);
          analogWrite(leftMotor2, 1023);
          analogWrite(rightMotor2, 1023);
          
  digitalWrite(leftMotor1,LOW);
  digitalWrite(leftMotor2,HIGH);
  digitalWrite(rightMotor1,LOW);
  digitalWrite(rightMotor2,HIGH);
}

/* command motor turn left */
void leftMotor(void)   
{
  analogWrite(leftMotor1, 0);
          analogWrite(rightMotor1, 500);
          analogWrite(leftMotor2, 500);
          analogWrite(rightMotor2, 0);
  
  digitalWrite(leftMotor1,LOW);
  digitalWrite(leftMotor2,HIGH);
  digitalWrite(rightMotor1,HIGH);
  digitalWrite(rightMotor2,LOW);

}

/* command motor turn right */
void rightMotor(void)   
{
  analogWrite(leftMotor1, 500);
          analogWrite(rightMotor1, 0);
          analogWrite(leftMotor2, 0);
          analogWrite(rightMotor2, 500);
          
  digitalWrite(leftMotor1,HIGH);
  digitalWrite(leftMotor2,LOW);
  digitalWrite(rightMotor1,LOW);
  digitalWrite(rightMotor2,HIGH);
}

/* command motor stop */
void stopMotor(void)   
{
  analogWrite(leftMotor1, 0);
          analogWrite(rightMotor1, 0);
          analogWrite(leftMotor2, 0);
          analogWrite(rightMotor2, 0);
          
  digitalWrite(leftMotor1,LOW);
  digitalWrite(leftMotor2,LOW);
  digitalWrite(rightMotor1,LOW);
  digitalWrite(rightMotor2,LOW);
}

/* connecting WiFi */
void connectWiFi()
{
  Serial.println("Connecting to WIFI");
  WiFi.begin(ssid, password);
  while ((!(WiFi.status() == WL_CONNECTED)))
  {
    delay(300);
    Serial.print("..");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("NodeMCU Local IP is : ");
  Serial.print((WiFi.localIP()));
}

/* check command received from Android Device */
String checkClient (void)
{
  while(!client.available()) delay(1); 
  String request = client.readStringUntil('\r');
  request.remove(0, 5);
  request.remove(request.length()-9,9);
  return request;
}

/* send command echo back to android device */
void sendBackEcho(String echo)
{
  client.println("HTTP/1.1 200 OK");
  client.println("Content-Type: text/html");
  client.println("");
  client.println("<!DOCTYPE HTML>");
  client.println("<html>");
  client.println(echo);
  client.println("</html>");
  client.stop();
  delay(1);
}