解释代码void I2C_reg_handle(uint8_t reg, uint8_t data) { if (reg < REG_LED0 || reg >= REG_NO_MAX) return; system_st.i2c_registers[reg] = data; if (reg == REG_WDI) system_st.emStateTmp = data; if (reg == REG_LED) { if (data) GPIO_WriteHigh(GPIOD, GPIO_PIN_4); else GPIO_WriteLow(GPIOD, GPIO_PIN_4); } if (reg == REG_SLEEP_START) { system_st.sleep_time_start[system_st.sleep_time_idx++] = data; if (system_st.sleep_time_idx >= 5) { system_st.sleep_time_idx = 0; system_st.sleep_time_start_cnt = system_st.sleep_time_start[0]*16*16*16*16 + system_st.sleep_time_start[1]*16*16*16 + system_st.sleep_time_start[2]*16*16 + system_st.sleep_time_start[3]*16 + system_st.sleep_time_start[4]; system_st.sleep_time_start_cnt *= 500; /* convert to jiffies counter */ main_st.sleep_time_start_jiffies = main_st.sys_jiffies; } } else if (reg == REG_SLEEP_STOP) { system_st.sleep_time_stop[system_st.sleep_time_idx++] = data; if (system_st.sleep_time_idx >= 5) { system_st.sleep_time_idx = 0; system_st.sleep_time_stop_cnt = system_st.sleep_time_stop[0]*16*16*16*16 + system_st.sleep_time_stop[1]*16*16*16 + system_st.sleep_time_stop[2]*16*16 + system_st.sleep_time_stop[3]*16 + system_st.sleep_time_stop[4]; system_st.sleep_time_stop_cnt *= 500; /* convert to jiffies counter */ main_st.sleep_time_stop_jiffies = main_st.sys_jiffies; } } }

这段代码是一个函数定义，函数名为 `I2C_reg_handle` ，接受两个参数 `reg` 和 `data` ，都是 uint8_t 类型。函数的作用是处理 I2C 寄存器的值。

首先，代码通过判断 `reg` 的取值范围，如果不在 `REG_LED0` 和 `REG_NO_MAX` 之间，则直接返回，不做任何处理。

然后，代码将 `data` 的值赋给 `system_st.i2c_registers[reg]` ，即将 I2C 寄存器的值更新为 `data` 。

接下来，代码根据不同的 `reg` 值做了一些特定的处理：
- 如果 `reg` 的值等于 `REG_WDI` ，则将 `data` 的值赋给 `system_st.emStateTmp` 。
- 如果 `reg` 的值等于 `REG_LED` ，则根据 `data` 的值来控制一个 LED 的状态。如果 `data` 为真，则将 GPIOD 的第 4 个引脚置高，否则将其置低。
- 如果 `reg` 的值等于 `REG_SLEEP_START` ，则将 `data` 的值存入 `system_st.sleep_time_start` 数组，并根据数组中的值计算出睡眠时间的计数器，并记录下当前的时间戳。
- 如果 `reg` 的值等于 `REG_SLEEP_STOP` ，则将 `data` 的值存入 `system_st.sleep_time_stop` 数组，并根据数组中的值计算出睡眠结束时间的计数器，并记录下当前的时间戳。

这段代码的作用是根据传入的寄存器和数据值，更新相应的状态和执行相应的操作。

相关问题

stm32如何使用HAL库实现硬件i2c

使用HAL库实现硬件I2C，需要按照以下步骤：

1. 初始化I2C总线，包括I2C的GPIO管脚初始化和I2C外设初始化。

2. 配置I2C的工作模式，包括传输速率、地址长度等。

3. 发送I2C起始信号。

4. 发送I2C设备地址和读写标志。

5. 写入数据或读取数据。

6. 发送I2C停止信号。

以下是一个使用HAL库实现I2C读写的例程：

#include "stm32f4xx_hal.h"

I2C_HandleTypeDef hi2c1;

void MX_I2C1_Init(void)
{
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 100000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
}

void HAL_I2C_MspInit(I2C_HandleTypeDef* i2cHandle)
{
  GPIO_InitTypeDef GPIO_InitStruct;
  if(i2cHandle->Instance==I2C1)
  {
    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_I2C1_CLK_ENABLE();

    GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF4_I2C1;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
  }
}

void HAL_I2C_MspDeInit(I2C_HandleTypeDef* i2cHandle)
{
  if(i2cHandle->Instance==I2C1)
  {
    __HAL_RCC_I2C1_FORCE_RESET();
    __HAL_RCC_I2C1_RELEASE_RESET();

    HAL_GPIO_DeInit(GPIOB, GPIO_PIN_6|GPIO_PIN_7);
  }
}

void I2C_Read(uint8_t address, uint8_t reg, uint8_t* data, uint16_t size)
{
  HAL_I2C_Mem_Read(&hi2c1, address, reg, I2C_MEMADD_SIZE_8BIT, data, size, 100);
}

void I2C_Write(uint8_t address, uint8_t reg, uint8_t* data, uint16_t size)
{
  HAL_I2C_Mem_Write(&hi2c1, address, reg, I2C_MEMADD_SIZE_8BIT, data, size, 100);
}

上述代码中，MX_I2C1_Init()函数进行I2C总线的初始化配置。I2C_Read()和I2C_Write()函数分别实现了I2C的读取和写入操作。具体实现可参考HAL库的API文档。

ESP32-IDF SDMMC读写BMI160保存陀螺仪加速度数据代码

以下是ESP32-IDF SDMMC读写BMI160保存陀螺仪加速度数据的示例代码：

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_err.h"
#include "driver/sdmmc_host.h"
#include "sdmmc_cmd.h"
#include "driver/gpio.h"
#include "driver/i2c.h"

#define SDMMC_PIN_NUM_MISO 2
#define SDMMC_PIN_NUM_MOSI 15
#define SDMMC_PIN_NUM_CLK  14
#define SDMMC_PIN_NUM_CS   13

#define I2C_MASTER_SCL_IO           22          /*!< gpio number for I2C master clock */
#define I2C_MASTER_SDA_IO           23          /*!< gpio number for I2C master data  */
#define I2C_MASTER_NUM              I2C_NUM_0   /*!< I2C port number for master dev */
#define I2C_MASTER_FREQ_HZ          100000      /*!< I2C master clock frequency */

#define BMI160_I2C_ADDR             0x68        /*!< I2C address of BMI160 */

#define SDMMC_CARD_INTR_GPIO        GPIO_NUM_34 /*!< GPIO number for SDMMC interrupt */

#define BUFFER_SIZE                512         /*!< Size of the buffer for SD card operations */

static sdmmc_card_t *card;

#define BMI160_REG_ACCD_X_LSB       0x12
#define BMI160_REG_ACCD_X_MSB       0x13
#define BMI160_REG_ACCD_Y_LSB       0x14
#define BMI160_REG_ACCD_Y_MSB       0x15
#define BMI160_REG_ACCD_Z_LSB       0x16
#define BMI160_REG_ACCD_Z_MSB       0x17
#define BMI160_REG_GYRD_X_LSB       0x0C
#define BMI160_REG_GYRD_X_MSB       0x0D
#define BMI160_REG_GYRD_Y_LSB       0x0E
#define BMI160_REG_GYRD_Y_MSB       0x0F
#define BMI160_REG_GYRD_Z_LSB       0x10
#define BMI160_REG_GYRD_Z_MSB       0x11

static esp_err_t i2c_master_init(void)
{
    int i2c_master_port = I2C_MASTER_NUM;
    i2c_config_t conf;
    conf.mode = I2C_MODE_MASTER;
    conf.sda_io_num = I2C_MASTER_SDA_IO;
    conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
    conf.scl_io_num = I2C_MASTER_SCL_IO;
    conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
    conf.master.clk_speed = I2C_MASTER_FREQ_HZ;
    i2c_param_config(i2c_master_port, &conf);
    return i2c_driver_install(i2c_master_port, conf.mode, 0, 0, 0);
}

static esp_err_t bmi160_write_reg(uint8_t reg_addr, uint8_t data)
{
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, BMI160_I2C_ADDR << 1 | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, reg_addr, true);
    i2c_master_write_byte(cmd, data, true);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    return ret;
}

static esp_err_t bmi160_read_reg(uint8_t reg_addr, uint8_t *data)
{
    if (data == NULL) {
        return ESP_ERR_INVALID_ARG;
    }
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, BMI160_I2C_ADDR << 1 | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, reg_addr, true);
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, BMI160_I2C_ADDR << 1 | I2C_MASTER_READ, true);
    i2c_master_read_byte(cmd, data, I2C_MASTER_NACK);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    return ret;
}

static void sdmmc_card_init()
{
    sdmmc_host_t host = SDMMC_HOST_DEFAULT();
    sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
    slot_config.gpio_cd = SDMMC_CARD_INTR_GPIO;
    slot_config.width = 1;
    sdmmc_card_t *card;
    esp_err_t ret = sdmmc_host_init_slot(&host, &slot_config, &card);
    if (ret != ESP_OK) {
        printf("Failed to initialize SD card.\n");
        return;
    }
    ret = sdmmc_card_init(&host, card);
    if (ret != ESP_OK) {
        printf("Failed to initialize SD card.\n");
        return;
    }
    ret = sdmmc_card_set_voltage(card, 3.3);
    if (ret != ESP_OK) {
        printf("Failed to set SD card voltage.\n");
        return;
    }
    printf("SD card initialized and ready to use.\n");
}

static void sdmmc_card_write(char *filename, void *data, size_t size)
{
    FILE *file = fopen(filename, "w");
    if (file == NULL) {
        printf("Failed to open file for writing.\n");
        return;
    }
    size_t write_size = fwrite(data, 1, size, file);
    if (write_size != size) {
        printf("Failed to write data to file.\n");
    } else {
        printf("Data written to file successfully.\n");
    }
    fclose(file);
}

void app_main()
{
    // Initialize I2C master
    esp_err_t ret = i2c_master_init();
    if (ret != ESP_OK) {
        printf("Failed to initialize I2C master.\n");
        return;
    }

    // Initialize SD card
    sdmmc_card_init();

    // Initialize BMI160
    bmi160_write_reg(0x7E, 0x15); // Reset
    vTaskDelay(100 / portTICK_RATE_MS);
    bmi160_write_reg(0x7E, 0x11); // Enable accelerometer and gyroscope
    bmi160_write_reg(0x41, 0x28); // Accelerometer normal mode, 100Hz
    bmi160_write_reg(0x42, 0x28); // Gyroscope normal mode, 100Hz

    // Read data from BMI160 and save to SD card
    while (1) {
        uint8_t buffer[BUFFER_SIZE];
        size_t buffer_size = 0;
        uint8_t data[6];
        bmi160_read_reg(BMI160_REG_ACCD_X_LSB, &data[0]);
        bmi160_read_reg(BMI160_REG_ACCD_X_MSB, &data[1]);
        bmi160_read_reg(BMI160_REG_ACCD_Y_LSB, &data[2]);
        bmi160_read_reg(BMI160_REG_ACCD_Y_MSB, &data[3]);
        bmi160_read_reg(BMI160_REG_ACCD_Z_LSB, &data[4]);
        bmi160_read_reg(BMI160_REG_ACCD_Z_MSB, &data[5]);
        buffer_size = sprintf((char *) buffer, "%d,%d,%d,%d,%d,%d\n", (int16_t) (data[1] << 8 | data[0]), (int16_t) (data[3] << 8 | data[2]), (int16_t) (data[5] << 8 | data[4]), 0, 0, 0);
        sdmmc_card_write("/sdcard/acc.txt", buffer, buffer_size);
        bmi160_read_reg(BMI160_REG_GYRD_X_LSB, &data[0]);
        bmi160_read_reg(BMI160_REG_GYRD_X_MSB, &data[1]);
        bmi160_read_reg(BMI160_REG_GYRD_Y_LSB, &data[2]);
        bmi160_read_reg(BMI160_REG_GYRD_Y_MSB, &data[3]);
        bmi160_read_reg(BMI160_REG_GYRD_Z_LSB, &data[4]);
        bmi160_read_reg(BMI160_REG_GYRD_Z_MSB, &data[5]);
        buffer_size = sprintf((char *) buffer, "%d,%d,%d,%d,%d,%d\n", 0, 0, 0, (int16_t) (data[1] << 8 | data[0]), (int16_t) (data[3] << 8 | data[2]), (int16_t) (data[5] << 8 | data[4]));
        sdmmc_card_write("/sdcard/gyr.txt", buffer, buffer_size);
        vTaskDelay(10 / portTICK_RATE_MS);
    }
}

该示例代码通过初始化I2C总线、SD卡和BMI160加速度计陀螺仪，然后在一个while循环中不断读取BMI160的数据，并将其存储至SD卡中。其中，BMI160的读写操作使用了ESP32的I2C API，而SD卡的读写操作使用了标准的C文件操作API。注意，在使用SD卡前，需要将其格式化并挂载到ESP32的文件系统中。