RN7302芯片的SPI读写代码

以下是RN7302芯片的SPI读写代码示例（以C语言为例）：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/spi/spidev.h>

#define SPI_DEVICE "/dev/spidev0.0"
#define SPI_MODE SPI_MODE_0
#define SPI_BITS_PER_WORD 8
#define SPI_SPEED_HZ 1000000

int spi_fd;

void spi_init() {
    spi_fd = open(SPI_DEVICE, O_RDWR);
    if (spi_fd < 0) {
        fprintf(stderr, "Error opening SPI device: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }

    uint8_t mode = SPI_MODE;
    if (ioctl(spi_fd, SPI_IOC_WR_MODE, &mode) < 0) {
        fprintf(stderr, "Error setting SPI mode: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }

    uint8_t bits_per_word = SPI_BITS_PER_WORD;
    if (ioctl(spi_fd, SPI_IOC_WR_BITS_PER_WORD, &bits_per_word) < 0) {
        fprintf(stderr, "Error setting SPI bits per word: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }

    uint32_t speed_hz = SPI_SPEED_HZ;
    if (ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed_hz) < 0) {
        fprintf(stderr, "Error setting SPI speed: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
}

void spi_transfer(uint8_t *tx_buf, uint8_t *rx_buf, size_t len) {
    struct spi_ioc_transfer transfer = {
        .tx_buf = (unsigned long)tx_buf,
        .rx_buf = (unsigned long)rx_buf,
        .len = len,
        .delay_usecs = 0,
        .speed_hz = SPI_SPEED_HZ,
        .bits_per_word = SPI_BITS_PER_WORD,
    };

    if (ioctl(spi_fd, SPI_IOC_MESSAGE(1), &transfer) < 0) {
        fprintf(stderr, "Error during SPI transfer: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
}

void spi_close() {
    close(spi_fd);
}

int main(int argc, char *argv[]) {
    spi_init();

    uint8_t tx_buf[2] = {0x01, 0x23};
    uint8_t rx_buf[2];
    spi_transfer(tx_buf, rx_buf, 2);

    printf("Received: 0x%02x 0x%02x\n", rx_buf[0], rx_buf[1]);

    spi_close();
    return 0;
}

这段代码使用Linux系统提供的spidev驱动，通过SPI总线与RN7302芯片进行通信。开头的宏定义部分可以根据具体的硬件配置进行调整。`spi_init()`函数用于初始化SPI总线，`spi_transfer()`函数用于进行SPI读写操作，`spi_close()`函数用于关闭SPI总线。在主函数中，我们可以先构造需要发送的数据，然后调用`spi_transfer()`函数进行SPI读写操作。在SPI读写完成后，我们可以从`rx_buf`缓冲区中获取读取到的数据。