int led1 = 13;
int led2 = 12;
int sw1 = 2;
int sw2 = 3;
bool sw_state2=0,last_sw_state,buttonstat2e=1,change=0;
bool state=0;
unsigned long time1;
int debounceDelay=40;
bool LED1State=0;
unsigned long delayTime1;
unsigned long delayA0;

void setup() 
{
  pinMode(led1,OUTPUT);  
  pinMode(led2,OUTPUT); 
  pinMode(sw1,INPUT_PULLUP);  
  Serial.begin(115200);
}
{
  pinMode(sw1,OUTPUT);  
  pinMode(led2,OUTPUT); 
  pinMode(sw2,INPUT_PULLUP);  
  Serial.begin(115200);
}
void loop() 
{
  checkSW();
  if(state==0){ digitalWrite(led2,LOW);} 
  else{ digitalWrite(led2,HIGH);}
  
  if ((millis() - delayTime1) > 1000)
  {
   LED1State=!LED1State;
   digitalWrite(led1, LED1State);
   delayTime1=millis();
  }

  if ((millis() - delayA0) > 500)
  {
   int sensorValue = analogRead(A0);
   float volt = sensorValue*5.0/1024;
   int outputPWM = map(sensorValue,0,1023,0,255);
   analogWrite(6,outputPWM);
   Serial.print("ADC:");
   Serial.print(sensorValue);
   Serial.print(" volt:");
   Serial.println(volt);
   delayA0=millis();
  }
}                                                                     


void checkSW()
{
  sw_state=digitalRead(sw1);
  if(sw_state!= last_sw_state)
  {
    time1=millis();
  }
  if((millis()-time1)>debounceDelay)
  {
    if(buttonstate!=sw_state)
    {
    buttonstate2=sw_state;
    change=1;
    }   
  }

  if((buttonstate2==1)&&(change==1))
  {
    state=!state; 
    change=0;
  }
  if((buttonstate==1)&&(change==1))
  {
    change=0;
  }
  last_sw_state=sw_state;
}