ESP-IDF 四线MMC/SD卡保存读写BMI160陀螺仪加速度数据代码

以下是ESP-IDF中四线MMC/SD卡保存读写BMI160陀螺仪加速度数据的示例代码：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "sdmmc_cmd.h"
#include "sdmmc_cmd_api.h"
#include "esp_vfs_fat.h"
#include "ff.h"
#include "bmi160.h"

#define PIN_NUM_MISO 2
#define PIN_NUM_MOSI 15
#define PIN_NUM_CLK  14
#define PIN_NUM_CS   13

#define SPI_DMA_CHAN 2

#define SD_CARD_OPEN_RETRY_COUNT 10

#define FILE_NAME "/sdcard/bmi160_data.txt"

spi_device_handle_t spi;

esp_err_t sd_card_init(void)
{
    //初始化SD卡驱动
    sdmmc_host_t host = SDMMC_HOST_DEFAULT();
    sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();

    //设置SD卡的SPI引脚
    gpio_set_pull_mode(PIN_NUM_CS, GPIO_PULLUP_ONLY);
    slot_config.gpio_cs = PIN_NUM_CS;
    slot_config.width = 4;

    //初始化SD卡对象
    sdmmc_card_t *card;
    esp_err_t ret = sdmmc_host_init_slot(&host, &slot_config, SD_CARD_OPEN_RETRY_COUNT, &card);
    if (ret != ESP_OK) {
        printf("Failed to initialize the SD card, error=%d", ret);
        return ret;
    }

    //初始化FAT文件系统
    static const char *mount_point = "/sdcard";
    sdmmc_card_print_info(stdout, card);
    esp_vfs_fat_mount_config_t mount_config = {
        .format_if_mount_failed = true,
        .max_files = 4,
        .allocation_unit_size = 16 * 1024
    };
    ret = esp_vfs_fat_mount(mount_point, card->drv, &mount_config, &card);
    if (ret != ESP_OK) {
        printf("Failed to mount FAT filesystem, error=%d", ret);
        sdmmc_card_deinit(card);
        return ret;
    }

    return ESP_OK;
}

void spi_master_init(void)
{
    spi_bus_config_t buscfg = {
        .miso_io_num = PIN_NUM_MISO,
        .mosi_io_num = PIN_NUM_MOSI,
        .sclk_io_num = PIN_NUM_CLK,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1
    };

    spi_device_interface_config_t devcfg = {
        .clock_speed_hz = 1 * 1000 * 1000,
        .mode = 0,
        .spics_io_num = PIN_NUM_CS,
        .queue_size = 7,
        .flags = SPI_DEVICE_NO_DUMMY | SPI_DEVICE_HALFDUPLEX
    };

    //初始化SPI总线和SPI设备
    esp_err_t ret = spi_bus_initialize(HSPI_HOST, &buscfg, SPI_DMA_CHAN);
    ESP_ERROR_CHECK(ret);
    ret = spi_bus_add_device(HSPI_HOST, &devcfg, &spi);
    ESP_ERROR_CHECK(ret);
}

void bmi160_init(void)
{
    bmi160_init_sensor();
    bmi160_config_sens(BMI160_ACCEL_NORMAL_MODE, BMI160_GYRO_NORMAL_MODE, &spi);
    bmi160_set_fifo_down(BMI160_FIFO_DOWN_1);
    bmi160_set_acc_range(BMI160_ACCEL_RANGE_2G);
    bmi160_set_gyro_range(BMI160_GYRO_RANGE_2000_DPS);
}

void app_main(void)
{
    //初始化SD卡和SPI总线
    sd_card_init();
    spi_master_init();

    //初始化BMI160陀螺仪加速度传感器
    bmi160_init();

    //打开文件
    FIL file;
    esp_err_t ret = f_open(&file, FILE_NAME, FA_WRITE | FA_OPEN_ALWAYS);
    if (ret != ESP_OK) {
        printf("Failed to open file %s, error=%d", FILE_NAME, ret);
        return;
    }

    //开始读取FIFO中的数据并写入文件
    while (1) {
        uint8_t fifo_data[1024];
        uint8_t acc_data[6];
        uint8_t gyro_data[6];
        uint16_t fifo_length;

        //读取FIFO数据
        bmi160_get_fifo_length(&fifo_length);
        if (fifo_length > 0) {
            fifo_length = fifo_length > sizeof(fifo_data) ? sizeof(fifo_data) : fifo_length;
            bmi160_read_fifo_data(fifo_data, fifo_length, &spi);

            //将数据写入文件
            for (int i=0; i<fifo_length; i+=12) {
                memcpy(acc_data, &fifo_data[i], 6);
                memcpy(gyro_data, &fifo_data[i+6], 6);

                char buf[128];
                sprintf(buf, "%d %d %d %d %d %d\n", (int16_t)(acc_data[1]<<8 | acc_data[0]), (int16_t)(acc_data[3]<<8 | acc_data[2]), (int16_t)(acc_data[5]<<8 | acc_data[4]),
                        (int16_t)(gyro_data[1]<<8 | gyro_data[0]), (int16_t)(gyro_data[3]<<8 | gyro_data[2]), (int16_t)(gyro_data[5]<<8 | gyro_data[4]));
                f_write(&file, buf, strlen(buf), NULL);
            }
        }
    }

    //关闭文件
    f_close(&file);
}

在该示例代码中，我们首先初始化了SD卡驱动和SPI总线，并通过BMI160陀螺仪加速度传感器读取了FIFO中的数据，并将其写入到SD卡的文件中。需要注意的是，在运行该代码前，需要将SD卡插入ESP32的SD卡槽中，并在ESP32上进行正确的引脚连接。