#include <SoftwareSerial.h>
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

RF24 radio(7, 8); // CE, CSN

const byte address[6] = "00001";

// input pins
const byte Xin      = A0;   // X input connected to A0
const byte Yin      = A1;   // Y input connected to A1
const byte Buttonin = 4;    // pushbuttom input connected to Digital pin 7


// output pins (only if necessary) 
int ledPin  = 13;        // select the pin for the blue LED PB0


// state machine
int state       = 0; 


//threshold because of physical limitation 533 centre of joystick at x axis
const int THRESHOLD_LOW_X   = 523;
const int THRESHOLD_HIGH_X  = 543;

//threshold because of physical limitation 522 centre of joystick at y axis
const int THRESHOLD_LOW_Y   = 512;
const int THRESHOLD_HIGH_Y  = 532;

// joystick value
int sensorValuex,sensorValuey, buttonState;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);               // initialize serial communication

  //Input
  pinMode (Buttonin, INPUT_PULLUP); // internal pull up resistor
  pinMode (Xin, INPUT);             // initialize Xin as INPUT 
  pinMode (Yin, INPUT);             // initialize YZin as INPUT

  //Output
  pinMode(ledPin, OUTPUT);      // declare the ledPin as an OUTPUT
  digitalWrite(ledPin, HIGH);   // turn the LED on (HIGH is the voltage level)

  //radio setup NRF24L01
  radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_MIN);
  radio.stopListening();

}

void loop() {
  // put your main code here, to run repeatedly:
  

  readPotentiometer(); 
  //moveAxis();
}

void readPotentiometer(){
  sensorValuex  = analogRead(Xin);  
  sensorValuey  = analogRead(Yin);
  buttonState   = digitalRead(Buttonin); 
   
  // send the sensor Value of x through radio
  radio.write(&sensorValuex, sizeof(sensorValuex));
  delay(5);
  /*
  Serial.print("  Axis XY");
  Serial.print("  X:");
  Serial.print(sensorValuex); 
  Serial.print("  Y:");
  Serial.println(sensorValuey);  
  */
}

void moveAxis(){
 
  
  if(state == 0){
    readPotentiometer();
    if(sensorValuex > THRESHOLD_HIGH_X){ //move right
      state = 1;
    }else if(sensorValuex < THRESHOLD_LOW_X){ //move left
      state = 2;
    }else if(sensorValuey > THRESHOLD_HIGH_Y){ //move down
      state = 3;
    }else if(sensorValuey < THRESHOLD_LOW_Y){ //move up
      state = 4;
    }
  }else if(state ==1){
    Serial.println("MOVE RIGHT");
    readPotentiometer();
    if((sensorValuex < THRESHOLD_HIGH_X)&& (sensorValuex > THRESHOLD_LOW_X)){                          
          state = 0;                  // joy stick at the centre back to state 0
    }  
    
  }else if(state ==2){
    Serial.println("MOVE LEFT");  
    readPotentiometer();
    if((sensorValuex < THRESHOLD_HIGH_X)&& (sensorValuex > THRESHOLD_LOW_X)){                          
          state = 0;                  // joy stick at the centre back to state 0
    }  
    
  }else if(state ==3){
    Serial.println("MOVE DOWN"); 
    readPotentiometer();
    if((sensorValuey < THRESHOLD_HIGH_Y)&& (sensorValuey > THRESHOLD_LOW_Y)){                          
          state = 0;                  // joy stick at the centre back to state 0
    }  
    
  }else if(state ==4){
    Serial.println("MOVE UP"); 
    readPotentiometer();
    if((sensorValuey < THRESHOLD_HIGH_Y)&& (sensorValuey > THRESHOLD_LOW_Y)){                          
          state = 0;                  // joy stick at the centre back to state 0
    }
    
  }
  
}