#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/spi_master.h"

// Define the SPI bus and device configurations
#define SPI_BUS  VSPI_HOST
#define MAX7219_CS_PIN GPIO_NUM_5

// Define the SPI transaction configuration
spi_device_handle_t spi;

void initialize_spi() {
    // SPI bus configuration
    spi_bus_config_t bus_config = {
        .mosi_io_num = GPIO_NUM_27, // MOSI pin
        .sclk_io_num = GPIO_NUM_12, // CLK pin
    };

    // Initialize the SPI bus
    spi_bus_initialize(SPI_BUS, &bus_config, 0);

    // SPI device configuration
    spi_device_interface_config_t dev_config = {
        .mode = 0,                    // SPI mode 0
        .clock_speed_hz = 10000000,    // Clock speed (1 MHz)
        .spics_io_num = GPIO_NUM_14,  // CS pin
        .queue_size = 1,              // Queue size
    };

    // Add the SPI device to the bus
    spi_bus_add_device(SPI_BUS, &dev_config, &spi);
}

void set_first_dot() {
    uint8_t data[2] = {0x08, 0xFF}; // Address of the first digit (DIG0) and value to display (binary 1)

    spi_transaction_t t;
    memset(&t, 0, sizeof(t));
    t.length = 16;         // Total data length, in bits
    t.tx_buffer = data;    // Data buffer to transmit

    // Transmit the data
    spi_device_transmit(spi, &t);
}

extern "C" void app_main() {
    initialize_spi();
    set_first_dot();
    vTaskDelay(1000 / portTICK_RATE_MS); // Delay for 1 second to see the dot

    // Clean up and free SPI device
    spi_bus_remove_device(spi);
}