单片机GD32F303RCT6 (Macos环境)开发 （三十四）—— 数字加速度计 （ADXL345）

数字加速度计 （ADXL345）- 计算xyz轴重力值

1、i2c总线读取

1、接线
上一节的软件模式i2c的方式，选择PB10(SCL) PB11(SDA)。

	GD32                       ADXL345
	PB10      ---------------  SCL
	PB11      ---------------  SDA
	3.3       ---------------  3.3
	GND       ---------------  GND
	3.3       ---------------  CS

CS接高电平时，才会使能ADXL345 的i2c总线。

2、封装对寄存器读写函数。

可根据自己的平台换i2c读写函数，或者spi读写函数。

static void adxl345_write_reg(uint8_t reg,uint8_t data)
{
#if SW_IIC == 1
    swi2c_device_write_data(ADXL345_ADDR,®,1,&data,1);
#endif    
}

static void adxl345_read_reg(uint8_t reg,uint8_t *data)
{
#if SW_IIC == 1
    swi2c_device_read_data(ADXL345_ADDR,®,1,data,1);
#endif 
}

static void adxl345_get_x_y_z_data(uint8_t reg,uint8_t *data,uint16_t len)
{
#if SW_IIC == 1
    swi2c_device_read_data(ADXL345_ADDR,®,1,data,len);
#endif   
}

3、ADXL345的寄存器

上图看出，xyz轴的数据存在0x32-0x37寄存器中，所以我们通过设置其他寄存器去初始化ADXL345后，从这六个寄存器读取数据就好了。

4、ADXL345的初始化代码

每个寄存器的每个功能都有初始化，对着规格书很容易就能明白。

void adxl345_xyz_read_init()
{
    uint8_t id = 0;
    uint8_t reg;
    uint8_t watermark;
    uint8_t x_offset;
    uint8_t y_offset;
    uint8_t z_offset;
    uint8_t tap_threshold;
    uint8_t tap_duration;
    uint8_t tap_window;
    uint8_t latent;
    uint8_t action_threshold;
    uint8_t inaction_threshold;
    uint8_t inaction_time;
    uint8_t fall_threshold;
    uint8_t free_fall_time;
    adxl345_interrupt_active_level_t it_level;
    adxl345_bool_t auto_sleep_enable;
    adxl345_bool_t sleep_enable;
    adxl345_sleep_frequency_t sleep_freq;
    adxl345_mode_t fifo_mode;
    adxl345_interrupt_pin_t interrupt_pin;

    adxl345_get_device_id(&id);
    if (id == 0xe5)
    {
        adxl345_set_interrupt_active_level(ADXL345_INTERRUPT_ACTIVE_LEVEL_LOW);     // 设置中断为低电平
        adxl345_get_interrupt_active_level(&it_level);
        printf("adxl345_get_interrupt_active_level == 0x%02x\r\n",it_level);

        adxl345_set_auto_sleep(ADXL345_BOOL_FALSE);                                 // 设置自动休眠为关
        adxl345_get_auto_sleep(&auto_sleep_enable);
        printf("adxl345_get_auto_sleep == 0x%02x\r\n",auto_sleep_enable);

        adxl345_set_sleep(ADXL345_BOOL_FALSE);                                      // 置为0，普通工作模式，置为1 ，休眠模式
        adxl345_get_sleep(&sleep_enable);
        printf("adxl345_get_sleep == 0x%02x\r\n",sleep_enable);

        adxl345_set_sleep_frequency(ADXL345_SLEEP_FREQUENCY_1HZ);
        adxl345_get_sleep_frequency(&sleep_freq);
        printf("adxl345_get_sleep_frequency == 0x%02x\r\n",sleep_freq);

        adxl345_set_fifo_mode(ADXL345_MODE_BYPASS);
        adxl345_get_fifo_mode(&fifo_mode);
        printf("adxl345_get_fifo_mode == 0x%02x\r\n",fifo_mode);

        adxl345_set_trigger_pin(ADXL345_INTERRUPT_PIN1);
        adxl345_get_trigger_pin(&interrupt_pin);
        printf("adxl345_get_trigger_pin == 0x%02x\r\n",interrupt_pin);

        adxl345_set_watermark(0x1F);
        adxl345_get_watermark(&watermark);
        printf("adxl345_get_watermark == 0x%02x\r\n",watermark);

        //set x y z offset
        adxl345_offset_convert_to_register(0.0f,®);
        adxl345_set_offset(reg,reg,reg);
        adxl345_get_offset((uint8_t *)&x_offset,(uint8_t *)&y_offset,(uint8_t *)&z_offset);
        printf("x_offset == 0x%02x y_offset == 0x%02x z_offset= 0x%02x\r\n",x_offset,y_offset,z_offset);

        /* set threshold 3g */
        adxl345_tap_threshold_convert_to_register(3.0f,®);
        /* set tap threshold */
        adxl345_set_tap_threshold(reg);
        adxl345_get_tap_threshold(&tap_threshold);
        printf("adxl345_get_tap_threshold == 0x%02x\r\n",tap_threshold);

        /* set 10 ms */
        adxl345_duration_convert_to_register(10 * 1000, (uint8_t *)®);
        /* set duration */
        adxl345_set_duration(reg);
        adxl345_get_duration(&tap_duration);
        printf("adxl345_get_duration == 0x%02x\r\n",tap_duration);

        /* set 20 ms */
        adxl345_latent_convert_to_register(20.0f, (uint8_t *)®);
        /* set latent */
        adxl345_set_latent(reg);
        adxl345_get_latent(&latent);
        printf("adxl345_get_latent == 0x%02x\r\n",latent);

        /* set 80 ms */
        adxl345_window_convert_to_register(80.0f, (uint8_t *)®);
        /* set windows time */
        adxl345_set_window(reg);
        adxl345_get_window(&tap_window);
        printf("adxl345_get_window == 0x%02x\r\n",tap_window);

        /* set x axis */
        adxl345_set_tap_axis(ADXL345_TAP_AXIS_X, ADXL345_BOOL_FALSE);
        adxl345_get_tap_axis(ADXL345_TAP_AXIS_X,®);
        printf("adxl345_get_tap_x_axis == 0x%02x\r\n",reg);
  
        /* set y axis */
        adxl345_set_tap_axis(ADXL345_TAP_AXIS_Y, ADXL345_BOOL_FALSE);
        adxl345_get_tap_axis(ADXL345_TAP_AXIS_Y,®);
        printf("adxl345_get_tap_y_axis == 0x%02x\r\n",reg);
 
        /* set z axis */
        adxl345_set_tap_axis(ADXL345_TAP_AXIS_Z, ADXL345_BOOL_FALSE);
        adxl345_get_tap_axis(ADXL345_TAP_AXIS_Z,®);
        printf("adxl345_get_tap_z_axis == 0x%02x\r\n",reg);

        /* disable suppress */
        adxl345_set_tap_suppress(ADXL345_BOOL_FALSE);
        adxl345_get_tap_suppress(®);
        printf("adxl345_get_tap_suppress == 0x%02x\r\n",reg);

        /* map int 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_SINGLE_TAP, ADXL345_INTERRUPT_PIN1);
        adxl345_get_interrupt_map(ADXL345_INTERRUPT_SINGLE_TAP, ®);
        printf("adxl345_get_interrupt_map == 0x%02x\r\n",reg);

        /* set single tap */
        adxl345_set_interrupt(ADXL345_INTERRUPT_SINGLE_TAP, ADXL345_BOOL_FALSE);
        adxl345_get_interrupt(ADXL345_INTERRUPT_SINGLE_TAP,®);
        printf("adxl345_get_interrupt == 0x%02x\r\n",reg);

        /* map int 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_DOUBLE_TAP, ADXL345_INTERRUPT_PIN1);
        adxl345_get_interrupt_map(ADXL345_INTERRUPT_DOUBLE_TAP, ®);
        printf("adxl345_get_interrupt_map == 0x%02x\r\n",reg);

        /* set double tap */
        adxl345_set_interrupt(ADXL345_INTERRUPT_DOUBLE_TAP, ADXL345_BOOL_FALSE);
        adxl345_get_interrupt(ADXL345_INTERRUPT_DOUBLE_TAP,®);
        printf("adxl345_get_interrupt == 0x%02x\r\n",reg);

        /* link activity and inactivity */
        adxl345_set_link_activity_inactivity(ADXL345_BOOL_FALSE);
        adxl345_get_link_activity_inactivity(®);
        printf("adxl345_get_link_activity_inactivity == 0x%02x\r\n",reg);

        adxl345_action_threshold_convert_to_register(2.0f,(uint8_t *)®);
        adxl345_set_action_threshold(reg);
        adxl345_get_action_threshold(&action_threshold);
        printf("adxl345_get_action_threshold == 0x%02x\r\n",action_threshold);

        adxl345_inaction_threshold_convert_to_register(1.0f, (uint8_t *)®);
        /* set inaction threshold */
        adxl345_set_inaction_threshold( reg);
        adxl345_get_inaction_threshold(&inaction_threshold);
        printf("adxl345_get_inaction_threshold == 0x%02x\r\n",inaction_threshold);

        /* set 3 s */
        adxl345_inaction_time_convert_to_register(3, (uint8_t *)®); 
        /* set inaction time */
        adxl345_set_inaction_time(reg);
        adxl345_get_inaction_time(&inaction_time);
        printf("adxl345_get_inaction_time == 0x%02x\r\n",inaction_time);

        /* set action x */
        adxl345_set_action_inaction(ADXL345_ACTION_X, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_ACTION_X,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);

        /* set action y */
        adxl345_set_action_inaction(ADXL345_ACTION_Y, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_ACTION_Y,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);   
        
        /* set action z */
        adxl345_set_action_inaction(ADXL345_ACTION_Z, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_ACTION_Z,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);    
        
        /* set inaction x */
        adxl345_set_action_inaction(ADXL345_INACTION_X, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_INACTION_X,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);
        
        /* set inaction y */
        adxl345_set_action_inaction(ADXL345_INACTION_Y, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_INACTION_Y,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);    
        
        /* set inaction z */
        adxl345_set_action_inaction(ADXL345_INACTION_Z, ADXL345_BOOL_FALSE);
        adxl345_get_action_inaction(ADXL345_INACTION_Z,®);
        printf("adxl345_get_action_inaction == 0x%02x\r\n",reg);

        /* set action ac coupled */
        adxl345_set_action_coupled(ADXL345_COUPLED_AC);
        adxl345_get_action_coupled(®);
        printf("adxl345_get_action_coupled == 0x%02x\r\n",reg);

        /* set inaction dc coupled */
        adxl345_set_inaction_coupled(ADXL345_COUPLED_DC);
        adxl345_get_inaction_coupled(®);
        printf("adxl345_get_inaction_coupled == 0x%02x\r\n",reg);

        /* map int 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_ACTIVITY, ADXL345_INTERRUPT_PIN1);
        /* set activity */
        adxl345_set_interrupt(ADXL345_INTERRUPT_ACTIVITY, ADXL345_BOOL_FALSE);

        /* map int 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_INACTIVITY, ADXL345_INTERRUPT_PIN1);
        /* set inactivity */
        adxl345_set_interrupt(ADXL345_INTERRUPT_INACTIVITY, ADXL345_BOOL_FALSE);
   
        /* set free fall */
        adxl345_free_fall_threshold_convert_to_register( 0.8f, (uint8_t *)®);     
        /* set free fall threshold */
        adxl345_set_free_fall_threshold(reg);
        adxl345_get_free_fall_threshold(&fall_threshold);
        printf("adxl345_get_free_fall_threshold == 0x%02x\r\n",fall_threshold);

        /* set 10 ms */
        adxl345_free_fall_time_convert_to_register(10, (uint8_t *)®);
        /* set free fall time */
        adxl345_set_free_fall_time(reg);
        adxl345_get_free_fall_time(&free_fall_time);
        printf("adxl345_get_free_fall_time == 0x%02x\r\n",free_fall_time);

        /* set interrupt 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_FREE_FALL, ADXL345_INTERRUPT_PIN1);
   
        /* set fall */
        adxl345_set_interrupt(ADXL345_INTERRUPT_FREE_FALL, ADXL345_BOOL_FALSE);

        /* set interrupt 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_DATA_READY, ADXL345_INTERRUPT_PIN1);
        /* set data ready */
        adxl345_set_interrupt(ADXL345_INTERRUPT_DATA_READY, ADXL345_BOOL_FALSE);
   
        /* set interrupt 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_WATERMARK, ADXL345_INTERRUPT_PIN1);
        /* set water mark */
        adxl345_set_interrupt(ADXL345_INTERRUPT_WATERMARK, ADXL345_BOOL_FALSE);

        /* set interrupt 1 */
        adxl345_set_interrupt_map(ADXL345_INTERRUPT_OVERRUN, ADXL345_INTERRUPT_PIN1);
        /* set over run */
        adxl345_set_interrupt(ADXL345_INTERRUPT_OVERRUN, ADXL345_BOOL_FALSE);

        /* set justify right */
        adxl345_set_justify(ADXL345_JUSTIFY_RIGHT);
        adxl345_get_justify(®);
        printf("adxl345_get_justify == 0x%02x\r\n",reg);
        /* set 100 rate */
        adxl345_set_rate(ADXL345_RATE_100);
        adxl345_get_rate(®);
        printf("adxl345_get_rate == 0x%02x\r\n",reg);

        /* set full resolution */
        adxl345_set_full_resolution(ADXL345_BOOL_TRUE);
        adxl345_get_full_resolution(®);
        printf("adxl345_get_full_resolution == 0x%02x\r\n",reg);
        /* 2g */
        adxl345_set_range(ADXL345_RANGE_4G);
        adxl345_get_range(®);
        printf("adxl345_get_range == 0x%02x\r\n",reg);

        /* start measure */
        adxl345_set_measure(ADXL345_BOOL_TRUE);
    
        adxl345_get_measure(®);
        printf("adxl345_get_measure == 0x%02x\r\n",reg);

        uint8_t xyz_data[6] = {0};
        uint16_t x_data;
        uint16_t y_data;
        uint16_t z_data;

        while(1)
        {
            adxl345_get_x_y_z_data(ADXL345_REG_DATAX0,xyz_data,6);
            x_data = (int16_t)(xyz_data[1] << 8) | xyz_data[0];                                              /* set raw z */
            y_data = (int16_t)(xyz_data[3] << 8) | xyz_data[2];                                              /* set raw y */
            z_data = (int16_t)(xyz_data[5] << 8) | xyz_data[4];  
            
            printf("adxl345_get_x_data == %0.2f g\r\n",(float)x_data * 0.0039f);
            printf("adxl345_get_y_data == %0.2f g\r\n",(float)y_data * 0.0039f);
            printf("adxl345_get_z_data == %0.2f g\r\n",(float)z_data * 0.0039f);	
            
            delay_1ms(1000);
        }
    }  

5、各寄存器设置跟读取函数

/**
 * 获取设备ID的函数
*/
static void adxl345_get_device_id(uint8_t *id)
{
    adxl345_read_reg(ADXL345_REG_DEVID,id);
}

/**
 * 设置中断是高电平还是低电平的函数
*/
static uint8_t adxl345_set_interrupt_active_level(adxl345_interrupt_active_level_t active_level)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_DATA_FORMAT,&value);
    value &= ~(1 << 5);                                                                          /* clear config */
    value |= (active_level << 5); 
    delay_1ms(1);     
    adxl345_write_reg(ADXL345_REG_DATA_FORMAT,value);

    return 0;
}

static uint8_t adxl345_get_interrupt_active_level(adxl345_interrupt_active_level_t *active_level)
{
    uint8_t value = 0;
    adxl345_read_reg(ADXL345_REG_DATA_FORMAT,&value);
    value &= (0x01<<5);
    *active_level = (adxl345_interrupt_active_level_t )(value >> 5);
    return 0;
}

static uint8_t adxl345_set_auto_sleep(adxl345_bool_t enable)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);
    value &= ~(1 << 4);                                                                        /* clear config */
    value |= enable << 4;  
    delay_1ms(1);      
    adxl345_write_reg(ADXL345_REG_POWER_CTL,value);

    return 0;
}

static uint8_t adxl345_get_auto_sleep(adxl345_bool_t *enable)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);
    value &= (0x01 << 4);
    *enable = (adxl345_bool_t )(value >> 4);

    return 0;
}

static uint8_t adxl345_set_sleep(adxl345_bool_t enable)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);
    value &= ~(1 << 2);                                                                        /* clear config */
    value |= enable << 2;    
    delay_1ms(1);    
    adxl345_write_reg(ADXL345_REG_POWER_CTL,value);

    return 0;
}

static uint8_t adxl345_get_sleep(adxl345_bool_t *enable)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);

    value &= (0x01 << 2);                                                                        /* clear config */
    *enable = (adxl345_bool_t) (value >>2);
    return 0;
}

static uint8_t adxl345_set_sleep_frequency(adxl345_sleep_frequency_t sleep_frequency)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);
    value &= ~(0x03 << 0);                                                                        /* clear config */
    value |= (sleep_frequency << 0);    
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_POWER_CTL,value);
    return 0;
}

static uint8_t adxl345_get_sleep_frequency(adxl345_sleep_frequency_t *sleep_frequency)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_POWER_CTL,&value);
    value &= (0x03 << 0);                                                                        /* clear config */
    *sleep_frequency = (adxl345_sleep_frequency_t) (value >> 0);
    return 0;
}

static uint8_t adxl345_set_fifo_mode(adxl345_mode_t fifo_mode)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= ~(0x03 << 6);                                                                       /* clear config */
    value |= (fifo_mode << 6); 
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_FIFO_CTL,value);
    return 0;
}

static uint8_t adxl345_get_fifo_mode(adxl345_mode_t *fifo_mode)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= (0x03 << 6);                                                                       /* clear config */
    *fifo_mode = (adxl345_mode_t) value >> 6;
    return 0;
}

static uint8_t adxl345_set_trigger_pin(adxl345_interrupt_pin_t pin)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= ~(0x01<< 5);                                                                       /* clear config */
    value |= (pin << 5); 
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_FIFO_CTL,value);

    return 0;
}

static uint8_t adxl345_get_trigger_pin(adxl345_interrupt_pin_t *pin)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= (0x01<< 5);                                                                       /* clear config */
    *pin = (adxl345_interrupt_pin_t) value >> 5;
    return 0;
}

static uint8_t adxl345_set_watermark(uint8_t level)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= ~(0x1F<< 0);                                                                       /* clear config */
    value |= (level << 0); 
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_FIFO_CTL,value);
    return 0;
}

static uint8_t adxl345_get_watermark(uint8_t *level)
{
    int value = 0;
    adxl345_read_reg(ADXL345_REG_FIFO_CTL,&value);
    value &= (0x1F<< 0);                                                                       /* clear config */
    *level = value >> 0;
    return 0;
}

static uint8_t adxl345_offset_convert_to_register(float g, uint8_t *reg)
{
    *reg = (int8_t)(g / 0.0156f);    
    return 0;                                                                                   // 比例因子为15.6 mg/LSB(即0x7F = 2 g)。
}

static uint8_t adxl345_offset_convert_to_data(uint8_t reg, float *g)
{
    *g = (float)(reg) * 0.0156f;    
    return 0;
}

static uint8_t adxl345_set_offset(uint8_t x, uint8_t y, uint8_t z) 
{
    adxl345_write_reg(ADXL345_REG_OFSX,x);
    adxl345_write_reg(ADXL345_REG_OFSY,y);
    adxl345_write_reg(ADXL345_REG_OFSZ,z);

    return 0;
}

static uint8_t adxl345_get_offset(uint8_t *x, uint8_t *y, uint8_t *z) 
{
    adxl345_read_reg(ADXL345_REG_OFSX,x);
    adxl345_read_reg(ADXL345_REG_OFSY,y);
    adxl345_read_reg(ADXL345_REG_OFSZ,z);

    return 0;
}

static uint8_t adxl345_tap_threshold_convert_to_register(float g, uint8_t *reg)
{
    *reg = (uint8_t)(g / 0.0625f);        /* convert real data to register data */
    return 0;                             /* success return 0 */
}

static uint8_t adxl345_tap_threshold_convert_to_data(uint8_t reg, float *g)
{
    *g = (float)(reg) * 0.0625f;        /* convert raw data to real data */
    return 0;                           /* success return 0 */
}

static uint8_t adxl345_set_tap_threshold(uint8_t threshold)
{
    adxl345_write_reg(ADXL345_REG_THRESH_TAP ,threshold);        /* write config */
    return 0;
}

static uint8_t adxl345_get_tap_threshold(uint8_t *threshold)
{
    adxl345_read_reg(ADXL345_REG_THRESH_TAP ,threshold);       /* write config */
    return 0;
}

static uint8_t adxl345_duration_convert_to_register(uint32_t us, uint8_t *reg)
{
    *reg = (uint8_t)(us / 625);        /* convert real data to register data */
    return 0;                          /* success return 0 */
}

static uint8_t adxl345_duration_convert_to_data(uint8_t reg, uint32_t *us)
{
    *us = (uint32_t)((float)(reg) * 625.0f);        /* convert raw data to real data */
    return 0;                                       /* success return 0 */
}

static uint8_t adxl345_set_duration(uint8_t t) 
{
    adxl345_write_reg(ADXL345_REG_DUR, t);          /* write config */
    return 0;
}

static uint8_t adxl345_get_duration(uint8_t *t) 
{
    adxl345_read_reg(ADXL345_REG_DUR, t);          /* write config */
    return 0;
}

static uint8_t adxl345_latent_convert_to_register(float ms, uint8_t *reg)
{
    *reg = (uint8_t)(ms / 1.25f);        /* convert real data to register data */
    return 0;                            /* success return 0 */
}

static uint8_t adxl345_latent_convert_to_data(uint8_t reg, float *ms)
{
    *ms = (float)(reg) * 1.25f;        /* convert raw data to real data */
    return 0;                          /* success return 0 */
}

static uint8_t adxl345_set_latent(uint8_t t) 
{
    adxl345_write_reg(ADXL345_REG_LATENT, t);       /* write config */
    return 0;
}

static uint8_t adxl345_get_latent(uint8_t *t) 
{
    adxl345_read_reg(ADXL345_REG_LATENT, t);       /* write config */
    return 0;
}

static uint8_t adxl345_window_convert_to_register(float ms, uint8_t *reg)
{
    *reg = (uint8_t)(ms / 1.25f);        /* convert real data to register data */
    return 0;                            /* success return 0 */
}

static uint8_t adxl345_window_convert_to_data(uint8_t reg, float *ms)
{
    *ms = (float)(reg) * 1.25f;        /* convert raw data to real data */
    return 0;                          /* success return 0 */
}

uint8_t adxl345_set_window(uint8_t t)
{
    adxl345_write_reg(ADXL345_REG_WINDOW, t);       /* write config */
    return 0;
}

uint8_t adxl345_get_window(uint8_t *t)
{
    adxl345_read_reg(ADXL345_REG_WINDOW, t);       /* write config */
    return 0;
}

static uint8_t adxl345_set_tap_axis(adxl345_tap_axis_t axis, adxl345_bool_t enable)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_TAP_AXES,(uint8_t *)&prev);                        /* read config */
 
    prev &= ~(1 << axis);                                                                   /* clear axis */
    prev |= enable << axis;                                                                 /* set axis */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_TAP_AXES, prev);             /* write config */
    return 0;
}

static uint8_t adxl345_get_tap_axis(adxl345_tap_axis_t axis, adxl345_bool_t *enable)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_TAP_AXES,(uint8_t *)&prev);                                /* read config */  
    prev &= (1 << axis);                                                                   /* clear axis */
    *enable = (adxl345_bool_t)(prev >> axis);                                                            /* set axis */
    
    return 0;
}

static uint8_t adxl345_set_tap_suppress(adxl345_bool_t enable)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_TAP_AXES,(uint8_t *)&prev);                        /* read config */
 
    prev &= ~(1 << 3);                                                                       /* clear suppress */
    prev |= enable << 3;                                                                   /* set axis */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_TAP_AXES, prev);             /* write config */
    return 0;
}

static uint8_t adxl345_get_tap_suppress(adxl345_bool_t *enable)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_TAP_AXES,(uint8_t *)&prev);                                /* read config */  
    prev &= (1 << 3);                                                                      /* clear config */
    *enable = (adxl345_bool_t)(prev >> 3);   

    return 0;
}

static uint8_t adxl345_set_interrupt_map(adxl345_interrupt_t type, adxl345_interrupt_pin_t pin)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_INT_MAP, (uint8_t *)&prev);                                /* read config */

    prev &= ~(1 << type);                                                                   /* clear type */
    prev |= pin << type;  
    delay_1ms(1);            
    adxl345_write_reg(ADXL345_REG_INT_MAP, prev);                                          /* write config */
    return 0;
}

static uint8_t adxl345_get_interrupt_map(adxl345_interrupt_t type, adxl345_interrupt_pin_t *pin)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_INT_MAP, (uint8_t *)&prev);                                /* read config */
    prev &= (1 << type);                                                                    /* clear config */
    *pin = (adxl345_interrupt_pin_t)(prev >> type);   

    return 0;
}

static uint8_t adxl345_set_interrupt(adxl345_interrupt_t type, adxl345_bool_t enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_INT_ENABLE, (uint8_t *)&prev);                              /* read config */
 
    prev &= ~(1 << type);                                                                       /* clear interrupt */
    prev |= enable << type; 
    delay_1ms(1);                                                                    /* set interrupt */
    adxl345_write_reg(ADXL345_REG_INT_ENABLE, prev);                             /* write config */

    return 0;
}

static uint8_t adxl345_get_interrupt(adxl345_interrupt_t type, adxl345_bool_t *enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_INT_ENABLE, (uint8_t *)&prev);                              /* read config */
    
    prev &= (1 << type);                                                                     /* clear config */
    *enable = (adxl345_bool_t)(prev >> type);    

    return 0;
}

static uint8_t adxl345_set_link_activity_inactivity(adxl345_bool_t enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_POWER_CTL, (uint8_t *)&prev);                                  /* read config */
 
    prev &= ~(1 << 5);                                                                          /* clear config */
    prev |= enable << 5;    
    delay_1ms(1);                                                                    /* set interrupt */
    adxl345_write_reg(ADXL345_REG_POWER_CTL, prev);                                             /* write config */

    return 0;

}

static uint8_t adxl345_get_link_activity_inactivity(adxl345_bool_t *enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_POWER_CTL, (uint8_t *)&prev);                                  /* read config */
 
    prev &= 1 << 5;                                                                             /* get config */
    *enable = (adxl345_bool_t)(prev >> 5);   

    return 0;

}

static uint8_t adxl345_action_threshold_convert_to_register(float g, uint8_t *reg)
{
    *reg = (uint8_t)(g / 0.0625f);        /* convert real data to register data */
    return 0;                             /* success return 0 */
}

static uint8_t adxl345_action_threshold_convert_to_data(uint8_t reg, float *g)
{
    *g = (float)(reg) * 0.0625f;        /* convert raw data to real data */
    return 0;                           /* success return 0 */
}

static uint8_t adxl345_set_action_threshold(uint8_t threshold)
{
    adxl345_write_reg(ADXL345_REG_THRESH_ACT, threshold);       /* write config */
    return 0;
}

static uint8_t adxl345_get_action_threshold(uint8_t *threshold)
{
    adxl345_read_reg(ADXL345_REG_THRESH_ACT, threshold);       /* write config */
    return 0;
}

static uint8_t adxl345_inaction_threshold_convert_to_register(float g, uint8_t *reg)
{
    *reg = (uint8_t)(g / 0.0625f);        /* convert real data to register data */
    return 0;                             /* success return 0 */
}

static uint8_t adxl345_inaction_threshold_convert_to_data(uint8_t reg, float *g)
{
    *g = (float)(reg) * 0.0625f;        /* convert raw data to real data */
    return 0;                           /* success return 0 */
}

static uint8_t adxl345_set_inaction_threshold(uint8_t threshold)
{
    adxl345_write_reg(ADXL345_REG_THRESH_INACT, threshold);       /* write config */
    return 0;
}

static uint8_t adxl345_get_inaction_threshold(uint8_t *threshold)
{
    adxl345_read_reg(ADXL345_REG_THRESH_INACT, threshold);       /* read config */
    return 0;
}

static uint8_t adxl345_inaction_time_convert_to_register(uint8_t s, uint8_t *reg)
{
    *reg = s;                       /* convert real data to register data */
    return 0;                       /* success return 0 */
}

static uint8_t adxl345_inaction_time_convert_to_data(uint8_t reg, uint8_t *s)
{
    *s = reg;                       /* convert raw data to real data */
    return 0;                       /* success return 0 */
}

static void adxl345_set_inaction_time(uint8_t t)
{
    adxl345_write_reg(ADXL345_REG_TIME_INACT, t);       /* write config */
}

static void adxl345_get_inaction_time(uint8_t *t)
{
    adxl345_read_reg(ADXL345_REG_TIME_INACT, t);       /* write config */
}

static void adxl345_set_action_inaction(adxl345_action_inaction_t type, adxl345_bool_t enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);          /* read config */

    prev &= ~(1 << type);                                                                         /* clear type */
    prev |= (enable << type);                                                                     /* set type */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_ACT_INACT_CTL,prev);                          /* write config */
}

static void adxl345_get_action_inaction(adxl345_action_inaction_t type, adxl345_bool_t *enable)
{
    uint8_t prev;
    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);       /* read config */

    prev &= (1 << type);                                                                        /* get type */
    *enable = (adxl345_bool_t)(prev >> type);                                                   /* set type */                                                                                /* success return 0 */
}

static void adxl345_set_action_coupled(adxl345_coupled_t coupled)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);         /* read config */
 
    prev &= ~(1 << 7);                                                                            /* clear coupled */
    prev |= (coupled << 7);                                                                       /* set coupled */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_ACT_INACT_CTL,prev);       /* write config */
}

static void adxl345_get_action_coupled(adxl345_coupled_t *coupled)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);       /* read config */

    prev &= (1 << 7);                                                                           /* clear config */
    *coupled = (adxl345_coupled_t)(prev >> 7);                                                  /* set config */                                                                               /* success return 0 */
}

static void adxl345_set_inaction_coupled(adxl345_coupled_t coupled)
{
    uint8_t prev;

    
    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);       /* read config */

    prev &= ~(1 << 3);                                                                          /* clear config */
    prev |= (coupled << 3);                                                                     /* set inaction coupled */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_ACT_INACT_CTL, prev);     /* write config */
}

static void adxl345_get_inaction_coupled(adxl345_coupled_t *coupled)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_ACT_INACT_CTL, (uint8_t *)&prev);       /* read config */

    prev &= (1 << 3);                                                                           /* clear config */
    *coupled = (adxl345_coupled_t)(prev >> 3);                                                  /* set config */                                                                               /* success return 0 */
}

static void adxl345_free_fall_threshold_convert_to_register(float g, uint8_t *reg)
{
    *reg = (uint8_t)(g / 0.0625f);        /* convert real data to register data */
}

static void adxl345_free_fall_threshold_convert_to_data(uint8_t reg, float *g)
{
    *g = (float)(reg) * 0.0625f;        /* convert raw data to real data */
}

static void adxl345_set_free_fall_threshold(uint8_t threshold)
{
    adxl345_write_reg(ADXL345_REG_THRESH_FF, threshold);       /* write config */
}

static void adxl345_get_free_fall_threshold(uint8_t *threshold)
{
    adxl345_read_reg(ADXL345_REG_THRESH_FF, threshold);       /* write config */
}

static void adxl345_free_fall_time_convert_to_register(uint16_t ms, uint8_t *reg)
{
    *reg = (uint8_t)(ms / 5);        /* convert real data to register data */
}

static void adxl345_free_fall_time_convert_to_data(uint8_t reg, uint16_t *ms)
{
    *ms = reg * 5;                  /* convert raw data to real data */
}

static void adxl345_set_free_fall_time(uint8_t t)
{
    adxl345_write_reg(ADXL345_REG_TIME_FF, t);       /* write config */
}

static void adxl345_get_free_fall_time(uint8_t *t)
{
    adxl345_read_reg(ADXL345_REG_TIME_FF, t);       /* write config */
}

static void adxl345_set_justify(adxl345_justify_t enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);         /* read config */
    prev &= ~(1 << 2);                                                                          /* clear config */
    prev |= (enable << 2);                                                                      /* set justify */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_DATA_FORMAT, prev);       /* write config */
}

static void adxl345_get_justify(adxl345_justify_t *enable)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);                                /* read config */

    prev &= (1 << 2);                                                                         /* get config */
    *enable = (adxl345_justify_t)(prev >> 2);                                                 /* get justify */
}

static void adxl345_set_rate(adxl345_rate_t rate)
{
    uint8_t prev;
    
    adxl345_read_reg(ADXL345_REG_BW_RATE, (uint8_t *)&prev);                                    /* read config */

    prev &= ~(0x1F);                                                                            /* clear rate */
    prev |= rate;                                                                               /* set rate */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_BW_RATE, prev);                                               /* write config */
}

static void adxl345_get_rate(adxl345_rate_t *rate)
{
    uint8_t prev;

    adxl345_read_reg(ADXL345_REG_BW_RATE, (uint8_t *)&prev);                            /* read config */

    prev &= 0x1F;                                                                         /* clear config */
    *rate = (adxl345_rate_t)(prev);                                                       /* get rate */                                                                          /* success return 0 */
}

static void adxl345_set_full_resolution(adxl345_bool_t enable)
{
    uint8_t prev;
    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);         /* read config */
 
    prev &= ~(1 << 3);                                                                          /* clear resolution */
    prev |= (enable << 3);  
    delay_1ms(1);                                                                 /* set resolution */
    
    adxl345_write_reg(ADXL345_REG_DATA_FORMAT, prev );       /* write config */
}

static void adxl345_get_full_resolution(adxl345_bool_t *enable)
{
    uint8_t  prev;

    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);       /* read config */
    prev &= (1 << 3);                                                                         /* clear config */
    *enable = (adxl345_bool_t)(prev >> 3);                                                    /* set resolution */                                                                            /* success return 0 */
}

static void adxl345_set_range(adxl345_range_t range)
{
    uint8_t res, prev;
    

    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);         /* read config */

    prev &= ~(3 << 0);                                                                          /* clear config */
    prev |= (range << 0);                                                                       /* set range */
    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_DATA_FORMAT, prev);       /* write config */
}

static void adxl345_get_range(adxl345_range_t *range)
{
    uint8_t prev;
    adxl345_read_reg(ADXL345_REG_DATA_FORMAT, (uint8_t *)&prev);       /* read config */
    prev &= (3 << 0);                                                                         /* get config */
    *range = (adxl345_range_t)(prev >> 0);                                                    /* set range */
}

static void adxl345_set_measure(adxl345_bool_t enable)
{
    uint8_t prev;
    adxl345_read_reg(ADXL345_REG_POWER_CTL, (uint8_t *)&prev);                                  /* read config */

    prev &= ~(1 << 3);                                                                          /* clear config */
    prev |= enable << 3;                                                                        /* set measure */

    delay_1ms(1);
    adxl345_write_reg(ADXL345_REG_POWER_CTL,prev);                                              /* write config */
}

static void adxl345_get_measure(adxl345_bool_t *enable)
{
    uint8_t prev;
    adxl345_read_reg(ADXL345_REG_POWER_CTL, (uint8_t *)&prev);       /* read config */
    prev &= 1 << 3;                                                                         /* get config */
    *enable = (adxl345_bool_t)(prev >> 3);                                                  /* get measure */
}

6、头文件定义

#ifndef __ADXL345_H__
#define __ADXL345_H__

#include "gd32f30x.h"

#define ENABLE_ADXL345      1
#define ADXL345_ADDR        0xA6

#define ADXL345_REG_DEVID                 0x00        /**< device id register */
#define ADXL345_REG_THRESH_TAP            0x1D        /**< thresh tap register */
#define ADXL345_REG_OFSX                  0x1E        /**< x offset register */
#define ADXL345_REG_OFSY                  0x1F        /**< y offset register */
#define ADXL345_REG_OFSZ                  0x20        /**< z offset register */
#define ADXL345_REG_DUR                   0x21        /**< duration time register */
#define ADXL345_REG_LATENT                0x22        /**< latent register */
#define ADXL345_REG_WINDOW                0x23        /**< window register */
#define ADXL345_REG_THRESH_ACT            0x24        /**< act thresh register */
#define ADXL345_REG_THRESH_INACT          0x25        /**< inact thresh register */
#define ADXL345_REG_TIME_INACT            0x26        /**< inact time register */
#define ADXL345_REG_ACT_INACT_CTL         0x27        /**< act inact ctl register */
#define ADXL345_REG_THRESH_FF             0x28        /**< free fall thresh register */
#define ADXL345_REG_TIME_FF               0x29        /**< free fall time register */
#define ADXL345_REG_TAP_AXES              0x2A        /**< tap axes register */
#define ADXL345_REG_ACT_TAP_STATUS        0x2B        /**< act tap status register */
#define ADXL345_REG_BW_RATE               0x2C        /**< bandwidth rate register */
#define ADXL345_REG_POWER_CTL             0x2D        /**< power control register */
#define ADXL345_REG_INT_ENABLE            0x2E        /**< interrupt enable register */
#define ADXL345_REG_INT_MAP               0x2F        /**< interrupt map register */
#define ADXL345_REG_INT_SOURCE            0x30        /**< interrupt source register */
#define ADXL345_REG_DATA_FORMAT           0x31        /**< data format register */
#define ADXL345_REG_DATAX0                0x32        /**< data X0 register */
#define ADXL345_REG_DATAX1                0x33        /**< data X1 register */
#define ADXL345_REG_DATAY0                0x34        /**< data Y0 register */
#define ADXL345_REG_DATAY1                0x35        /**< data Y1 register */
#define ADXL345_REG_DATAZ0                0x36        /**< data Z0 register */
#define ADXL345_REG_DATAZ1                0x37        /**< data Z1 register */
#define ADXL345_REG_FIFO_CTL              0x38        /**< fifo control register */
#define ADXL345_REG_FIFO_STATUS           0x39        /**< fifo status register */

typedef enum
{
    ADXL345_BOOL_FALSE = 0x00,        /**< false */
    ADXL345_BOOL_TRUE  = 0x01,        /**< true */
} adxl345_bool_t;


typedef enum
{
    ADXL345_INTERRUPT_ACTIVE_LEVEL_HIGH = 0x00,        /**< interrupt active level high */
    ADXL345_INTERRUPT_ACTIVE_LEVEL_LOW  = 0x01,        /**< interrupt active level low */
} adxl345_interrupt_active_level_t;

/**
 * @brief adxl345 sleep frequency enumeration definition
 */
typedef enum
{
    ADXL345_SLEEP_FREQUENCY_8HZ = 0x00,        /**< sleep 8Hz */
    ADXL345_SLEEP_FREQUENCY_4HZ = 0x01,        /**< sleep 4Hz */
    ADXL345_SLEEP_FREQUENCY_2HZ = 0x02,        /**< sleep 2Hz */
    ADXL345_SLEEP_FREQUENCY_1HZ = 0x03,        /**< sleep 1Hz*/
} adxl345_sleep_frequency_t;

/**
 * @brief adxl345 mode enumeration definition
 */
typedef enum
{
    ADXL345_MODE_BYPASS  = 0x00,        /**< bypass mode */
    ADXL345_MODE_FIFO    = 0x01,        /**< fifo mode */
    ADXL345_MODE_STREAM  = 0x02,        /**< stream mode */
    ADXL345_MODE_TRIGGER = 0x03,        /**< trigger mode */
} adxl345_mode_t;

/**
 * @brief adxl345 interrupt pin enumeration definition
 */
typedef enum
{
    ADXL345_INTERRUPT_PIN1 = 0x00,        /**< interrupt pin 1 */
    ADXL345_INTERRUPT_PIN2 = 0x01,        /**< interrupt pin 2 */
} adxl345_interrupt_pin_t;

typedef enum
{
    ADXL345_TAP_AXIS_X = 0x02,        /**< x axis tap */
    ADXL345_TAP_AXIS_Y = 0x01,        /**< y axis tap */
    ADXL345_TAP_AXIS_Z = 0x00,        /**< z axis tap */
} adxl345_tap_axis_t;

typedef enum
{
    ADXL345_INTERRUPT_DATA_READY = 0x07,        /**< data ready */
    ADXL345_INTERRUPT_SINGLE_TAP = 0x06,        /**< single tap */
    ADXL345_INTERRUPT_DOUBLE_TAP = 0x05,        /**< double tap */
    ADXL345_INTERRUPT_ACTIVITY   = 0x04,        /**< activity */
    ADXL345_INTERRUPT_INACTIVITY = 0x03,        /**< inactivity */
    ADXL345_INTERRUPT_FREE_FALL  = 0x02,        /**< free fall */
    ADXL345_INTERRUPT_WATERMARK  = 0x01,        /**< watermark */
    ADXL345_INTERRUPT_OVERRUN    = 0x00,        /**< overrun */
} adxl345_interrupt_t;

typedef enum
{
    ADXL345_ACTION_X   = 0x06,        /**< x axis action */
    ADXL345_ACTION_Y   = 0x05,        /**< y axis action */
    ADXL345_ACTION_Z   = 0x04,        /**< z axis action */
    ADXL345_INACTION_X = 0x02,        /**< x axis inaction */
    ADXL345_INACTION_Y = 0x01,        /**< y axis inaction */
    ADXL345_INACTION_Z = 0x00,        /**< z axis inaction */
} adxl345_action_inaction_t;

typedef enum
{
    ADXL345_COUPLED_DC = 0x00,        /**< DC coupled */
    ADXL345_COUPLED_AC = 0x01,        /**< AC coupled */
} adxl345_coupled_t;

typedef enum
{
    ADXL345_JUSTIFY_RIGHT = 0x00,        /**< right justify */
    ADXL345_JUSTIFY_LEFT  = 0x01,        /**< left justify */
} adxl345_justify_t;

typedef enum
{
    ADXL345_RATE_0P1            = 0x00,        /**< 0.1Hz */
    ADXL345_RATE_0P2            = 0x01,        /**< 0.2Hz */
    ADXL345_RATE_0P39           = 0x02,        /**< 0.39Hz */
    ADXL345_RATE_0P78           = 0x03,        /**< 0.78Hz */
    ADXL345_RATE_1P56           = 0x04,        /**< 1.56Hz */
    ADXL345_RATE_3P13           = 0x05,        /**< 3.13Hz */
    ADXL345_RATE_6P25           = 0x06,        /**< 6.25Hz */
    ADXL345_RATE_12P5           = 0x07,        /**< 12.5Hz */
    ADXL345_RATE_25             = 0x08,        /**< 25Hz */
    ADXL345_RATE_50             = 0x09,        /**< 50Hz */
    ADXL345_RATE_100            = 0x0A,        /**< 100Hz */
    ADXL345_RATE_200            = 0x0B,        /**< 200Hz */
    ADXL345_RATE_400            = 0x0C,        /**< 400Hz */
    ADXL345_RATE_800            = 0x0D,        /**< 800Hz */
    ADXL345_RATE_1600           = 0x0E,        /**< 1600Hz */
    ADXL345_RATE_3200           = 0x0F,        /**< 3200Hz */
    ADXL345_LOW_POWER_RATE_12P5 = 0x17,        /**< low power 12.5Hz */
    ADXL345_LOW_POWER_RATE_25   = 0x18,        /**< low power 25Hz */
    ADXL345_LOW_POWER_RATE_50   = 0x19,        /**< low power 50Hz */
    ADXL345_LOW_POWER_RATE_100  = 0x1A,        /**< low power 100Hz */
    ADXL345_LOW_POWER_RATE_200  = 0x1B,        /**< low power 200Hz */
    ADXL345_LOW_POWER_RATE_400  = 0x1C,        /**< low power 400Hz */
} adxl345_rate_t;

typedef enum
{
    ADXL345_RANGE_2G  = 0x00,        /**< ±2G */
    ADXL345_RANGE_4G  = 0x01,        /**< ±4G */
    ADXL345_RANGE_8G  = 0x02,        /**< ±8G */
    ADXL345_RANGE_16G = 0x03,        /**< ±16G */
} adxl345_range_t;

void adxl345_xyz_read_init();
#endif

7、实验现象

main函数直接调用void adxl345_xyz_read_init()即可。

打印结果如下：

8、代码

代码路径：https://gitee.com/xiaoguo-tec_0/gd32-iap-code.git

9、注意

代码里要打印float数据，修改APPlication Makefile文件如下：

如果编译后文件太大，超出我们定义的50K，那么修改GD32F303RCTx_FLASH.ld文件，