#include<stdio.h>
#include<stdlib.h>
#include<fcntl.h>
#include<unistd.h>
#include<sys/ioctl.h>
#include<linux/spi/spidev.h>
// Define the SPI device path
#define SPI_DEVICE“/dev/spidev0.0”
// Set the SPI mode
unsigned char spi_mode = SPI_MODE_0;
// Set the number of bits per word
unsigned char spi_bits_per_mode = 8;
// Set the maximum SPI transfer speed in Hz
int spi_max_speed_hz = 1000000;
// Initialize the SPI device
int spi_init()
{
int fd;
// Open the SPI device file
fd = open(SPI_DEVICE, O_RDWR);
if (fd < 0)
{
perror(“Failed to open SPI device”);
return –1;
}
// Set the SPI mode
if (ioctl(fd, SPI_IOC_WR_MODE, &spi_mode) < 0)
{
perror(“Failed to set SPI mode”);
close(fd);
return –1;
}
// Set the number of bits per word
if (ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &spi_bits_per_mode) < 0)
{
perror(“Failed to set bits per word”);
close(fd);
return –1;
}
// Set the maximum transfer speed
if (ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi_max_speed_hz) < 0)
{
perror(“Failed to set maximum transfer speed”);
close(fd);
return –1;
}
return fd;
}
// Send an SPI data packet
int spi_send(intfd, unsignedchar *tx_buffer, unsignedchar *rx_buffer, size_tlength)
{
structspi_ioc_transfer tr = {
.tx_buf = (unsignedlong)tx_buffer,
.rx_buf = (unsignedlong)rx_buffer,
.len = length,
.speed_hz = spi_max_speed_hz,
.bits_per_word = spi_bits_per_mode,
};
// Perform the SPI transfer
if (ioctl(fd, SPI_IOC_MESSAGE(1), &tr) < 0)
{
perror(“SPI transfer failed”);
return –1;
}
return0;
}
int main()
{
int fd;
unsigned char tx_buffer[8] = {0x83, 0xd4, 0x0f, 0x00};
unsigned char rx_buffer[sizeof(tx_buffer)];
size_t length = sizeof(tx_buffer);
// Initialize the SPI device
fd = spi_init();
if (fd < 0)
{
return –1;
}
// Print the data to be sent
printf(“Data to be sent: “);
for (size_t i = 0; i < length; i++)
{
printf(“%02X “, tx_buffer[i]);
}
printf(“\n”);
// Send the SPI data packet
if (spi_send(fd, tx_buffer, rx_buffer, length) < 0)
{
close(fd);
return –1;
}
// Print the received data
printf(“Received data: “);
for (size_t i = 0; i < length; i++)
{
printf(“%02X “, rx_buffer[i]);
}
printf(“\n”);
// Close the SPI device
close(fd);
return0;
}