/*
 * Pico minicodes: Richard 07/15/2024
 * Cascading LED Bar Graph [KnightRider]
*/
#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include <stdio.h>


// Define the GPIO pins for the LED bar graph
#define LED_COUNT 10
uint led_pins[LED_COUNT] = {0, 1, 2, 3, 4,
                            5, 6, 7, 8, 9};

void setup();
void knight_rider();
void first_half();
void second_half();

int main() {
  stdio_init_all();
  sleep_ms(1000);
  printf("KnightRider cascading LEDs...\n");
  sleep_ms(4000);
  setup();

  while (true) {
    knight_rider();
    sleep_ms(170);  

    //first_half();
    //sleep_ms(1000);

    //second_half();
    //sleep_ms(1000); 
  }

  return 0;
}

void setup() {
  // Initialize the LED pins as output
  for (int i = 0; i < LED_COUNT; i++) {
    gpio_init(led_pins[i]);
    gpio_set_dir(led_pins[i], GPIO_OUT);
  }
}

void knight_rider() {
  // 1 forward, -1 reverse
  static int direction = 1;  
  static int position = 0;

  // Turn off all LEDs
  for (int i = 0; i < LED_COUNT; i++) {
    gpio_put(led_pins[i], 0);
  }

  // Turn on the current LED
  gpio_put(led_pins[position], 1);

  // Update the position
  position += direction;
  if (position == LED_COUNT - 1 || position == 0) {
    // Change direction at the ends
    direction = -direction;  
  }
}


void first_half() {
  // light first 5 LEDs and turn off last 5
  for (int i = 0; i < LED_COUNT; i++) {
    if (i < 5) {
      gpio_put(led_pins[i], 1);
    } else {
      gpio_put(led_pins[i], 0);
    }
  }
}

void second_half() {
  for (int i = 0; i < LED_COUNT; i++) {
     if (i >= 5) {
      gpio_put(led_pins[i], 1);
    } else {
      gpio_put(led_pins[i], 0);
    }
  }
}