int i ;
void setup() {
pinMode(9, OUTPUT);
Serial.begin(9600);
}

void loop() {
for( i =400; i <= 3000; i+= 2){
  digitalWrite(9, HIGH);
delayMicroseconds(i);
digitalWrite(9, LOW);
delayMicroseconds(700);
Serial.println(i);
  delay(90);
}
}

void loop(){
digitalWrite( IGBTPIN, 1);
delayMicroseconds(8000); //60hrz for 50 hrz 10 ms
digitalWrite( IGBTPIN, 0);
}

void variableDelay(unsigned int us){
    unsigned int i;
    for( i = us; i > 0; i-- ){
        delay(1);
    }
}
int interval = 1000;
char timePeriod[9] = {50, 25, 17, 12, 10, 8, 7, 6, 5 };

void setup() {
pinMode(9, OUTPUT);
Serial.begin(9600);
}

void loop() {

 for(char i= 0 ; i <9; i++){
    while(millis() < interval){
          digitalWrite(9, 1);
          variableDelay(timePeriod[i]);
          digitalWrite(9, 0);
          variableDelay(timePeriod[i]);
    }
    interval += 1000;   
    Serial.println(i);
 }
}

#define triac_control 9
#define sensorPin A1
#define zero_detect 2
volatile byte zero_bit = LOW;
#include <PID_v1.h>
double Setpoint, Input, Output;
double consKp=0.25, consKi=1, consKd=0.5;
PID myPID(&Input, &Output, &Setpoint, consKp, consKi, consKd, DIRECT);
          float analogValue = 0;
          int analogValue0 = 0;
          int analogmin = 4; 
          int analogmax = 1000;
          float kDev = 32.5;
void setup()  {
 pinMode(triac_control, OUTPUT);  
  pinMode(zero_detect, INPUT);
  attachInterrupt(0, zero_fun, RISING);
  Serial.begin(9600);
}


void loop() 
{
  myPID.SetSampleTime(10);
  myPID.SetMode(AUTOMATIC);
  myPID.SetOutputLimits(100, 5000);
  Input = analogRead(sensorPin); 
  analogValue = Output/kDev;
  analogValue0 = analogmax-analogValue+analogmin;
if (analogValue > analogmax) 
    {
      analogValue = analogmax;
    }
    Setpoint = 10;
    myPID.Compute();
    Serial.println(analogValue0);
     if (zero_bit == 1){
          delayMicroseconds(analogValue0); 
          digitalWrite(triac_control, 1);
          delayMicroseconds(100); 
          digitalWrite(triac_control, 0);
           zero_bit = 0;
           
           }
          
     }
    
    
          
    
    }
void zero_fun() // set bit
  {
        zero_bit = 1;  
  }