#include "pico/stdlib.h"
#include "hardware/i2c.h"
#include <stdio.h>

// Define I2C pins and DS1307 address
#define SDA_PIN 4  // GPIO pin for I2C SDA
#define SCL_PIN 5  // GPIO pin for I2C SCL
#define I2C_ADDR 0x68  // I2C address of the DS1307 RTC

// Function to set the date and time on the DS1307
void set_date_time() {
    // Arrays to store register addresses and corresponding values
    uint8_t second[2] = {0x00, 0x00};  // Register 0x00: Seconds (set to 0)
    uint8_t minute[2] = {0x01, 0x27};  // Register 0x01: Minutes (set to 27)
    uint8_t hour[2] = {0x02, 0x0D};    // Register 0x02: Hours (set to 13 in 24-hour format)
    uint8_t day[2] = {0x04, 0x24};     // Register 0x04: Day of the month (set to 24)
    uint8_t month[2] = {0x05, 0x09};   // Register 0x05: Month (set to September)
    uint8_t year[2] = {0x06, 0x24};    // Register 0x06: Year (set to 2024)

    // Array of pointers to the register-value pairs
    uint8_t *datetime[] = {second, minute, hour, day, month, year};

    // Iterate over the array and write each register-value pair to the DS1307
    for (int i = 0; i < 6; i++) {
        i2c_write_blocking(i2c0, I2C_ADDR, datetime[i], 2, false);
    }
}

// Function to read the date and time from the DS1307
void read_date_time(uint8_t *datetime) {
    uint8_t initial_register = 0x00;  // Start reading from register 0x00 (seconds)
    i2c_write_blocking(i2c0, I2C_ADDR, &initial_register, 1, true);  // Send the starting register address
    i2c_read_blocking(i2c0, I2C_ADDR, datetime, 7, false);  // Read 7 bytes (seconds, minutes, hours, day of week, day, month, year)
}

// Main function
int main() {
    stdio_init_all();  // Initialize standard I/O for USB communication
    i2c_init(i2c0, 100 * 1000);  // Initialize I2C with a 100 kHz clock speed
    gpio_set_function(SDA_PIN, GPIO_FUNC_I2C);  // Set SDA pin to I2C function
    gpio_set_function(SCL_PIN, GPIO_FUNC_I2C);  // Set SCL pin to I2C function
    gpio_pull_up(SDA_PIN);  // Enable pull-up resistor on SDA pin
    gpio_pull_up(SCL_PIN);  // Enable pull-up resistor on SCL pin

    set_date_time();  // Set the initial date and time on the DS1307

    while (true) {
        uint8_t datetime[7];  // Array to store the date and time values
        read_date_time(datetime);  // Read the current date and time from the DS1307

        // Print the date and time to the console
        printf("\nData: %02x/%02x/%02x - Horário: %02x:%02x:%02x\n",
               datetime[4], datetime[5], datetime[6],  // Day, Month, Year
               datetime[2], datetime[1], datetime[0]); // Hour, Minute, Second

        sleep_ms(5000);  // Wait for 5 seconds before reading again
    }
}