// Sweep through all 7-bit I2C addresses, to see if any slaves are present on
// the I2C bus. Print out a table that looks like this:
#include <stdio.h>
#include "pico/stdlib.h"
#include "pico/binary_info.h"
#include "hardware/i2c.h"

#define PICO_I2C_SDA_PIN 20
#define PICO_I2C_SCL_PIN 21
#define i2c_type_default 0

// I2C reserves some addresses for special purposes. We exclude these from
// the scan.
// These are any addresses of the form 000 0xxx or 111 1xxx
bool reserved_addr(uint8_t addr) {
    return (addr & 0x78) == 0 || (addr & 0x78) == 0x78;
}

int main() {
    stdio_init_all();
    // This example will use I2C0 on the default SDA and SCL pins.
    i2c_init(i2c_type_default, 100 * 1000);

    gpio_set_function(PICO_I2C_SDA_PIN, GPIO_FUNC_I2C);
    gpio_set_function(PICO_I2C_SCL_PIN, GPIO_FUNC_I2C);
    gpio_pull_up(PICO_I2C_SDA_PIN);
    gpio_pull_up(PICO_I2C_SCL_PIN);

    printf("I2C Bus Scan\n");
    for (int addr = 0; addr < (1 << 7); ++addr) {
        // Skip over any reserved addresses.
        int ret;
        uint8_t rxdata;
        if (reserved_addr(addr))
            ret = PICO_ERROR_GENERIC;
        else
            ret = i2c_read_blocking(i2c_default, addr, &rxdata, 1, false);

        if (ret > 0) {
            printf("Dispositivo encontrado 0x%x\n", addr);
        }
    }
}