Reddit traffic light blinker 1.0

/*
   Reddit traffic light controller --- August 17, 2020
   This just controls three LEDs using delays. It has no inputs at all.

*/

int red_led_pin = 10;
int yellow_led_pin = 9;
int green_led_pin = 8;

// Each LED has its own delay time set below.
unsigned long red_light_time = 5000;
unsigned long red_and_yellow_light_time = 2000;
unsigned long yellow_light_time = 3000;
unsigned long green_light_time = 3000;
// The delay() command can accept {int} and {unsigned int} values, but those only go up to 32 and 64 seconds (32,000 and 64,000).
// The {unsigned long} type can go up to about 4.2 million seconds, and it's the largest type that delay() accepts so I put it here.

// Normally I would say it's not a great idea to just use delays like this in a program,
//   but since all that this program does is blink some LEDs, delay() is good enough.

void setup() {
  pinMode(red_led_pin, OUTPUT);
  pinMode(yellow_led_pin, OUTPUT);
  pinMode(green_led_pin, OUTPUT);
  change_to_yellow(); // This makes the lights start with yellow only on.
}


void loop() {
  delay(yellow_light_time);

  change_to_red();
  delay(red_light_time);

  change_to_red_and_yellow();
  delay(red_and_yellow_light_time);

  change_to_green();
  delay(green_light_time);

  change_to_yellow();
}



void change_to_red() {
  changeLights(true, false, false);
}

void change_to_red_and_yellow() {
  changeLights(true, true, false);
}

void change_to_yellow() {
  changeLights(false, true, false);
}

void change_to_green() {
  changeLights(false, false, true);
}

void changeLights(bool red_on, bool yellow_on, bool green_on) {
  // This function accepts three boolean parameters.
  // The values set the red, yellow and green LED states in that order.
  digitalWrite(green_led_pin, green_on);
  digitalWrite(yellow_led_pin, yellow_on);
  digitalWrite(red_led_pin, red_on);
}


// [end of file]