#include <ESP8266WiFi.h>
#include <WiFiUdp.h>


unsigned long int a,b,c;
int x[15],ch1[15],ch[7],i;
//specifing arrays and variables to store values 

//Wifi Variables
const char* ssid = "WiFi-720P-51667B";
const char* password = "";
WiFiUDP Udp;
//unsigned int remoteUdpPort = 50000;
byte Packet[8];

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



  //Connect to Wifi
  Serial.printf("Connecting to %s ", ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" connected");



  //Enable interrupt on pin 2 

    pinMode(2, INPUT_PULLUP);
    attachInterrupt(digitalPinToInterrupt(2), read_me, FALLING);
    delay(500);
}

void loop() {
read_rc();

//Serial.print(ch[1]);Serial.print("\t");
//Serial.print((ch[2]));Serial.print("\t");
//Serial.print((ch[3]));Serial.print("\t");
//Serial.print((ch[4]));Serial.print("\t");
//Serial.print(ch[5]);Serial.print("\t");
//Serial.print(ch[6]);Serial.print("\n");


if (WiFi.status() == WL_CONNECTED) {
//Send UDP packet
//Packet = 0x66 0xRoll 0xPitch 0xThrottle 0xYaw 0xCommand 0xChecksum 0x99      all range 0/254 128 being zero
Packet[0] = 0x66;
Packet[1] =  0.317 * (ch[1] -100);
Packet[2] = 0.317 * (ch[2] -100);
Packet[3] = 0.317 * (ch[3] -100);
Packet[4] = 0.317 * (ch[4] -100);
if (ch[5] < 500)    Packet[5] = 0x20;    
else  Packet[5] = 0x04; 
Packet[6] = Packet[5] ^ Packet[4] ^ Packet[3] ^ Packet[2] ^ Packet[1] ;
Packet[7] = 0x99;
Serial.print(Packet[0],HEX);Serial.print(" ");
Serial.print((Packet[1]),HEX);Serial.print(" ");
Serial.print((Packet[2]),HEX);Serial.print(" ");
Serial.print((Packet[3]),HEX);Serial.print(" ");
Serial.print(Packet[4],HEX);Serial.print(" ");
Serial.print(Packet[5],HEX);Serial.print(" ");
Serial.print(Packet[6],HEX);Serial.print(" ");
Serial.print(Packet[7],HEX);Serial.print("\n");
//String outer = String(Packet);

Udp.beginPacket("192.168.0.1", 50000);
//Udp.write(outer);
Udp.write(Packet[0]);
Udp.write(Packet[1]);
Udp.write(Packet[2]);
Udp.write(Packet[3]);
Udp.write(Packet[4]);
Udp.write(Packet[5]);
Udp.write(Packet[6]);
Udp.write(Packet[7]);
Udp.endPacket();
} 
else {
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" connected");  
  
  
}
//generate aprox 50ms delay
delay(50); 
}


void read_me()  {
 //this code reads value from RC reciever from PPM pin (Pin 2 or 3)
 //this code gives channel values from 0-1000 values 
 //    -: ABHILASH :-    //
a=micros(); //store time value a when pin value falling
c=a-b;      //calculating time inbetween two peaks
b=a;        // 
x[i]=c;     //storing 15 value in array
i=i+1;       if(i==15){for(int j=0;j<15;j++) {ch1[j]=x[j];}
             i=0;}}//copy store all values from temporary array another array after 15 reading  
void read_rc(){
int i,j,k=0;
  for(k=14;k>-1;k--){if(ch1[k]>10000){j=k;}}  //detecting separation space 10000us in that another array                     
  for(i=1;i<=6;i++){ch[i]=(ch1[i+j]-1000);}}     //assign 6 channel values after separation space