MAX31865 Ошибка связи SPI

Question

У меня проблема с обменом данными с MAX31865. Я написал простое приложение linux, но когда я его запускаю, программа никогда не заканчивается. У меня нет ответа от MAX31865.

вот мой код (только конф):

static void transfer(int fd) 
{ 
    int ret; 
    uint8_t tx[] ={0x80}; 

    uint8_t rx[ARRAY_SIZE(tx)]; 
    struct spi_ioc_transfer tr = { 
     .tx_buf = (unsigned long)tx, 
     .rx_buf = (unsigned long)rx, 
     .len = ARRAY_SIZE(tx), 
     .delay_usecs = delay, 
     .speed_hz = 0, 
     .bits_per_word = 0, 
    }; 

    ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); 
    if (ret == 1) 
     pabort("can't send spi message"); 

} 

int main(int argc, char *argv[]) 
{ 
    int ret = 0; 
    int fd; 

    parse_opts(argc, argv); 

    fd = open(device, O_RDWR); 
    if (fd < 0) 
     pabort("can't open device"); 

    ret = ioctl(fd, SPI_IOC_WR_MODE, &mode); 
    if (ret == -1) 
     pabort("can't set spi mode"); 

    ret = ioctl(fd, SPI_IOC_RD_MODE, &mode); 
    if (ret == -1) 
     pabort("can't get spi mode"); 

    ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits); 
    if (ret == -1) 
     pabort("can't set bits per word"); 

    ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits); 
    if (ret == -1) 
     pabort("can't get bits per word"); 
    printf("%d",bits); 

    ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed); 
    if (ret == -1) 
     pabort("can't set max speed hz"); 

    ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed); 
    if (ret == -1) 
     pabort("can't get max speed hz"); 

    printf("spi mode: %d\n", mode); 
    printf("bits per word: %d\n", bits); 

    transfer(fd); 
    printf("max speed: %d Hz\n", speed); 

    transfer(fd); 

    close(fd); 

    return ret; 
} 

буду благодарен за любую помощь

Answer 1

Вот мой полный код. Я отмечаю, где проблема

#include <stdint.h> 
#include <unistd.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <getopt.h> 
#include <fcntl.h> 
#include <sys/ioctl.h> 
#include <linux/types.h> 
#include <linux/spi/spidev.h> 


static void pabort(const char *s) 
{ 
    perror(s); 
    abort(); 
} 

static const char *device = "/dev/spidev0.0"; 
static uint8_t mode = 3; 
static uint8_t bits = 8; 
static uint32_t speed = 1000000; 
static uint16_t delay; 

#define ARRAY_SIZE(a) (sizeof(a)/sizeof((a)[0])) 


static void transfer(int fd) 
{ 
    int ret; 
    uint8_t tx[] ={0x80}; 

    uint8_t rx[1]; 
    struct spi_ioc_transfer tr = { 
     .tx_buf = (unsigned long)tx, 
     .rx_buf = (unsigned long)rx, 
     .len = ARRAY_SIZE(tx), 
     .delay_usecs = delay, 
     .speed_hz = 0, 
     .bits_per_word = 0, 
    }; 

    ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); //->> this ioctl function makes problems 
    if (ret == 1) 
     pabort("can't send spi message"); 

} 

int main(int argc, char *argv[]) 
{ 
    int ret = 0; 
    int fd; 

    fd = open(device, O_RDWR); 
    if (fd < 0) 
     pabort("can't open device"); 

    ret = ioctl(fd, SPI_IOC_WR_MODE, &mode); 
    if (ret == -1) 
     pabort("can't set spi mode"); 

    ret = ioctl(fd, SPI_IOC_RD_MODE, &mode); 
    if (ret == -1) 
     pabort("can't get spi mode"); 

    ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits); 
    if (ret == -1) 
    pabort("can't set bits per word"); 

    ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits); 
    if (ret == -1) 
     pabort("can't get bits per word"); 
    printf("%d",bits); 

    ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed); 
    if (ret == -1) 
     pabort("can't set max speed hz"); 

    ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed); 
    if (ret == -1) 
     pabort("can't get max speed hz"); 

    printf("spi mode: %d\n", mode); 
    printf("bits per word: %d\n", bits); //---> This printf works fine 

    transfer(fd); 
    printf("max speed: %d Hz\n", speed); //--> This printf doesn't work 

    close(fd); 
}