#define True 1;
#define False 0;
const int numLEDS=4;
const int GPIO_Pins[]={1,5,9,13};
const int blinkRate=500;
static bool flag=True;
void setup() {
  // put your setup code here, to run once:
 for(int led=4;led<numLEDS;led++){
  pinMode(GPIO_Pins[led],OUTPUT);
 }
 // Serial1.begin(115200);
 // Serial1.println("Hello, Raspberry Pi Pico!");
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int led=0;led<numLEDS;led++){
    controlLEDs(led,flag);
  }
  delay(blinkRate);
  flag=!flag;

}
void controlLEDs(int led,bool state)
{
  if(state==true)
  digitalWrite(GPIO_Pins[led],HIGH);
  else
  digitalWrite(GPIO_Pins[led],LOW);
}