const int pwm = 2 ;    //naming pin 2 as ‘pwm’ variable 
const int adc = 0 ;   //naming pin 0 of analog input side as ‘adc’
float sum1,sum2,sum3,x1,x2,x3;
int n = 150;          //sampling rate
int i = 0;            //count
float vTh = 0.35;
int state;
float a1 = 0;
float a2 = 0;
float a3 = 0;

void setup()
{
     pinMode(pwm,OUTPUT) ;  //setting pin 2 as output
     Serial.begin(9600); // open the serial port at 9600 bps:
     state = 0;
}
void loop()
{    
     i++;
     
     int adc  = analogRead(0) ;    //reading analog voltage and storing it in an integer  
     sum1 += adc;

     
     //adc  = analogRead(0) ;
     //sum2 += adc;
     
     //adc  = analogRead(0) ;
     //sum3 += adc;

      if ( state == 0 && (a1 > vTh) && (a2 > vTh) && (a3 > vTh)) {
        digitalWrite(pwm,HIGH);
        state = 1;
        Serial.println(state);
        Serial.print("high ");
        Serial.print(a1);
        Serial.print(" ");
        Serial.print(a2);
        Serial.print(" ");
        Serial.println(a3);
      }
      if ( state == 1 && (a1 < vTh) && (a2 < vTh) && (a3 < vTh)) {
        digitalWrite(pwm,LOW);
        state = 0;
        Serial.println(state);
        Serial.print("low ");
        Serial.print(a1);
        Serial.print(" ");
        Serial.print(a2);
        Serial.print(" ");
        Serial.println(a3);
      }

      if (i == n) {
       //x1 = (sum1/n) * 0.049;
       //x2 = (sum2/n) * 0.049;
       //x3 = (sum3/n) * 0.049;
       Serial.println(state);
       a3 = (sum1/n) * 0.049;
       sum1 = 0;
       a1 = a2;
       a2 = a3;
       i = 0;
      }
       
       //sum1,sum2,sum3 = 0;
       
       //x1,x2,x3 = 0;
      delay(1);
}