#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "unistd.h"

// Define pins
const uint8_t dataPin = 13;
const uint8_t latchPin = 14;
const uint8_t clockPin = 15;

const uint8_t pinCount = 16;

// Define bit strings
const char* bitStrings[] = {
    "0000000000000001",
    "0000000000000010",
    "0000000000000100",
    "0000000000001000",
    "0000000000010000",
    "0000000000100000",
    "0000000001000000",
    "0000000010000000",
    "0000000100000000",
    "0000001000000000",
    "0000010000000000",
    "0000100000000000",
    "0001000000000000",
    "0010000000000000",
    "0100000000000000",
    "1000000000000000",
};

// Function to shift data into the 74HC595 register
void shift(const char* data) {
    // Start data sending
    gpio_put(latchPin, 0);
    gpio_put(clockPin, 0);
    gpio_put(latchPin, 1);

    // Load data in reverse order
    for (int i = 0; i < pinCount; i++) {
        gpio_put(clockPin, 0);
        uint8_t val = (data[i] == '1') ? 1 : 0;
        gpio_put(dataPin, val);  // Check if the bit is '1'
        gpio_put(clockPin, 1);
    }

    // Store data on register
    gpio_put(latchPin, 0);
    gpio_put(latchPin, 1);
}

int main() {
    stdio_init_all();

    // Initialize GPIO pins
    gpio_init(dataPin);
    gpio_init(latchPin);
    gpio_init(clockPin);

    // Set GPIO pin directions
    gpio_set_dir(dataPin, GPIO_OUT);
    gpio_set_dir(latchPin, GPIO_OUT);
    gpio_set_dir(clockPin, GPIO_OUT);

    int i = 0;

    while (1) {
        if (i == sizeof(bitStrings) / sizeof(bitStrings[0]))
            i = 0;
        // Call the shift function
        shift(bitStrings[i]);

        i++;
        sleep_ms(500);
    }

    return 0;
}