/* In this code, for the first five seconds LED1 blinks after every 200
milliseconds while LED2 blinks after every second. In the next five seconds,
this is reversed and LED1 now blinks after every second while LED2 blinks 
after every 200 milliseconds. This repeats itself.
*/

uint8_t led1 = 12, led2 = 4;
int previousMillis1 = 0,previousMillis2 = 0 ;
int countA = 0, countB = 0 ;
int delay1 = 200, delay2 = 1000;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);

}

void loop() {
  if ((millis()- previousMillis1)> delay1){ // for the first 5seconds LED1 blinks after 200ms
    previousMillis1 = millis();
    digitalWrite(led1, !digitalRead(led1));

    countA++;
  }
  if (countA == 25){ // for the next 5sec, LED1 blinks after everysecond
    delay1 = 1000;
  }

  if (countA == 30){ // for the next 5sec LED1 blinks after every 200ms
    countA = 0; // Count is reset to enable the function to loop
    delay1 = 200;
  }

  if ((millis()- previousMillis2)> delay2){ //for the first 5sec LED2 blinks after every second
    previousMillis2 = millis();
    digitalWrite(led2, !digitalRead(led2));

    countB++;
  }
  if (countB == 5){ //for the next 5sec LED2 blinks after every 200ms
    delay2 = 200;
  }

  if (countB == 30){ //for the next 5sec LED2 blinks after every second
    countB = 0; //Count is reset to enable the function to loop
    delay2 = 1000;
  }

}