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

#include <string.h>
#include "hardware/gpio.h"

#define I2C_ADDR 0x68 // Endereço do dispositivo I2C

static void BCD(char *buf, uint8_t val);

int main() {
    stdio_init_all();

    i2c_init(i2c0, 100 * 1000); // Inicializa I2C0 a 100khz
    gpio_set_function(4, GPIO_FUNC_I2C); // SDA
    gpio_set_function(5, GPIO_FUNC_I2C); // SCL
    gpio_pull_up(4); // Habilita pull-up para SDA
    gpio_pull_up(5); // Habilita pull-up para SCL

    while(true) {
        uint8_t regs[7];
        uint8_t aux[2];
        uint16_t pos = 0;
        int tpos = 1;
        char leitura[] = "Data: xx/xx/xx Hora: xx:xx:xx\n";
    
        if (tpos == 2) {
            aux[0] = pos >> 8;
            aux[1] = pos & 0xFF;
            i2c_write_blocking (i2c0, I2C_ADDR, aux, 2, true);
        } else {
            aux[0] = pos & 0xFF;
            i2c_write_blocking (i2c0, I2C_ADDR, aux, 1, true);
        }
        i2c_read_blocking(i2c0, I2C_ADDR, regs, 7, false);

        BCD (leitura+6, regs[4]);
        BCD (leitura+9, regs[5]);
        BCD (leitura+12, regs[6]);
        BCD (leitura+21, regs[2] & 0x3F);
        BCD (leitura+24, regs[1]);
        BCD (leitura+27, regs[0] & 0x7F);
        printf (leitura);
        
        sleep_ms(5000);
    }
    
    return 0;
}

// Converte numero BDC para ASCII
static void BCD (char *buf, uint8_t val) {
    buf[0] = (char) ((val >> 4) + '0');
    buf[1] = (char) ((val & 0x0F) + '0');
}