#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/pwm.h"

// Definition of LED pins
const uint LED_RED = 13;   // Pin for the red LED
const uint LED_BLUE = 12;  // Pin for the blue LED

// PWM settings
const uint16_t PERIOD_RED = 1000;   // PWM period for the red LED (1 kHz)
const uint16_t PERIOD_BLUE = 100;   // PWM period for the blue LED (10 kHz)
const float DIVIDER_PWM = 16.0;     // Fractional clock divider for PWM
const uint16_t MAX_DUTY_CYCLE = 100; // Maximum duty cycle (100%)

// Global variables
uint16_t red_duty_cycle = 5;   // Initial duty cycle for the red LED (5%)
uint16_t blue_duty_cycle = 5;  // Initial duty cycle for the blue LED (5%)
bool up_down = true;           // Variable to control the direction of the duty cycle

// Function to configure PWM for an LED
void setup_pwm(uint pin, uint16_t period) {
    uint slice = pwm_gpio_to_slice_num(pin); // Get the PWM slice associated with the pin
    gpio_set_function(pin, GPIO_FUNC_PWM);   // Configure the pin for PWM function
    pwm_set_clkdiv(slice, DIVIDER_PWM);      // Set the clock divider for PWM
    pwm_set_wrap(slice, period);             // Set the maximum counter value (PWM period)
    pwm_set_enabled(slice, true);            // Enable PWM on the corresponding slice
}

// Function to update the duty cycle of an LED
void update_duty_cycle(uint pin, uint16_t duty_cycle, uint16_t period) {
    uint16_t level = (duty_cycle * period) / 100; // Calculate the PWM level
    pwm_set_gpio_level(pin, level);              // Set the PWM level
}

// Main function
int main() {
    stdio_init_all(); // Initialize standard I/O

    // Configure PWM for the LEDs
    setup_pwm(LED_RED, PERIOD_RED);   // Configure PWM for the red LED (1 kHz)
    setup_pwm(LED_BLUE, PERIOD_BLUE); // Configure PWM for the blue LED (10 kHz)

    while (true) {
        // Update the duty cycle for the red LED
        update_duty_cycle(LED_RED, red_duty_cycle, PERIOD_RED);

        // Update the duty cycle for the blue LED
        update_duty_cycle(LED_BLUE, blue_duty_cycle, PERIOD_BLUE);

        // Wait for 2 seconds
        sleep_ms(2000);

        // Update the duty cycle (increment or decrement)
        if (up_down) {
            red_duty_cycle += 5;  // Increment the duty cycle for the red LED
            blue_duty_cycle += 5; // Increment the duty cycle for the blue LED
            if (red_duty_cycle >= MAX_DUTY_CYCLE || blue_duty_cycle >= MAX_DUTY_CYCLE) {
                up_down = false; // Change direction to decrement
            }
        } else {
            red_duty_cycle -= 5;  // Decrement the duty cycle for the red LED
            blue_duty_cycle -= 5; // Decrement the duty cycle for the blue LED
            if (red_duty_cycle <= 5 || blue_duty_cycle <= 5) {
                up_down = true; // Change direction to increment
            }
        }
    }
}